Digital Human Real-Time Rendering Setup

Intro

This page covers how to set up a realistic Digital Human in NVIDIA Omniverse using the RTX Real-Time Renderer.

DH_RT_Claire

RTX Real-Time Rendering With the “Claire” Digital Human Asset.

CLAIRE_HAIR_CUT

The Claire Asset in the Siggraph 2023 Hair Simulation Paper

Note

There is also a Siggraph 2022 Creating a Realistic Digital Human Portrait Tutorial for the RTX Path Tracing renderer.

Overview

Basic Stage Setup

Initial Setup

  • Set the viewport resolution to UHD(3840x2160) or HD1080P(1920x1080)

    Viewport_Res

    Set Viewport Resolution

    Note

    Set a higher resolution to get better detail in the render.

    Higher resolutions also provide better input for NVIDIA Deep Learning Super Sampling (DLSS)

  • Enable “Display UDIM Sequence”, to use <UDIM> file texture path

    FILEPICKER_UDIM

    File Browser GUI -> Top Right Corner Options Menu ->Display UDIM Sequence

Open Example Scene

A grey-shaded example USD scene is provided for you to start with.

To load the example scene:

  • Open USD Composer GUI

  • Open Example Tab: Window -> Browsers -> Examples

  • Double click the claire_lookdev_init to open the file

    LOAD_INIT_SCENE_GIF

    Open Initial Scene

    Window -> Browsers -> Examples -> Open claire_lookdev_init

  • Loaded scene:

    LOADED_INIT_SCENE

    Loaded Example Scene

Once opened, the scene should look like the image above, with the following assets included as Payload

  • Head model

  • Hair groom

  • Camera

  • Lighting

Note

The initial scene is read-only. Make sure to save a copy of it with a new name in your own file location.

Use the camera /World/Camera_60mm that’s included in the scene or create your own camera.

A light rig is also provided in the initial scene. To create your own lighting, you can hide or delete the prim /World/lightings in the stage.

Additionally, it sets “Render “Settings -> Real Time-> Common -> Geometry -> Curve Settings -> Global Number BVH Splits” to 4.

A higher BVH split number is less likely to crash with a heavy hair curve asset but uses more VRAM as a tradeoff.

BVH_SETTING

Curve BVH Split Setting

Important

If desired, a final example scene named claire_lookdev with fully setup materials can be opened through the “Example” tab.

Setting Up Materials

How to Create a New Material

Note

Omniverse ships with both built-in preset materials and Material Definition Language (MDL) graph material nodes if you want to build your own.

For this asset, using MDL graph nodes is preferred to have a finer level of control.

For more detail please go here

  • Open the MDL Graph Editor

    MDL_GRAPH_EDITOR_OPEN

    Open MDL Graph Editor

    Window -> Rendering -> MDL Material Graph

  • To create MDL graph nodes, search node type then drag to the work area:

    CREATE_MDL_NODES

    Search Node Type -> Drag to Work Area

Skin Materials

The skin material is built from multiple components:

Steps

Before

After

New Skin Material

Skin Normal

SKIN_NORMAL_BEFORE

SKIN_NORMAL_AFTER

Skin Diffuse and SSS

SKIN_DISSS_BEFORE

SKIN_DISSS_AFTER

Skin Spec

Skin Coat

SKIN_SPEC_BEFORE

SKIN_SPEC_AFTER

Skin Makeup

SKIN_MAKEUP_BEFORE

SKIN_MAKEUP_AFTER

Create New Material

  • Create a new material and name it “c_skin_graph”

  • Create an OmniSurfaceBase node and connect the outputs

    CREATE_NEW_MTL_GIF

    Create New material, Rename, Connect Outputs

  • Assign the material to

    /World/head_hi_model_published/char_model_hi/c_headWatertight_hi

Setup Skin Normal

The goal of the normal map node network is to:

  • Add the skin normal map

  • Blend in the skin micro detail

  • Emphasize normal strength in certain areas using masks, in this case areas other than the lips

TEMP_NORMAL_MAP_RESULT

The Normal Map

  • Add Normal map texture node

    NORMAL_NODE_GIF

    Add Normal Map Node

  • On the newly-created normal map node, set the skin normal map texture and properties

    SKIN_NORMAL_MAP_PROP

    Set Skin Normal Map and Properties:

    Normalmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_skin_geometryNormal.<UDIM>.exr

    Strength: 1.2

    Normal strength can be set to more than 1.0 to emphasize the surface bumpiness

    Flip V: OFF

    This texture is a right-handed normal map

  • Add another Normal map texture node, set the skin micro detail map texture map path

    SKIN_DETAIL_NORMAL_MAP_PROP

    Set Detail Normal Properties:

    Normalmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_skinMicro_geometryNormal.exr

    Tiling: 35

    To fit the scale of the micro detail

    Flip V: ON

    This texture is a left-handed normal map

  • Add a Bitmap texture node and name it “normal_blend_weight”. Set the skin normal weight map texture map path

    FILE_NODE_GIF

    Create Bitmap Texture Node

    SKIN_NORMAL_WEIGHT_PROP

    Skin Normal Weight Map and Properties

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_skin_geometryNormalWeight.<UDIM>.exr

  • Add a new Bitmap texture node and name it “file_texture_c_skin_lipsMask_1_invert”

  • Set the lip mask texture and properties

    LIP_MASK_1_INVERT_PROP

    Lip Mask Map Properties

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_skin_lipsMask.<UDIM>.exr

    Invert Image: ON

    Goal is to add micro skin normal detail in areas other than the lips

  • Add a Blend Normals node. The node name defaults to “blend_normals”

    BLEND_NORMAL_NODE

    Add Blend Normal Node

  • Add a multiply float node and name it “multiply_02”

    • Multiply it by 3x, e.g. three times the default normal strength

  • Add another multiply float node and name it “multiply_05”

    • Connect “multiply_02”.out -> “multiply_05”.a (first input)

    • Connect “file_texture_c_skin_lipsMask_1_invert”.r -> “multiply_05”.b (second input)

  • Connect normal nodes:

    NORMAL_NODES_NETWORK

    Connect Normal Map Nodes

    Skin normal map.out -> blend_normals.base_normal

    Skin detail normal map.out -> blend_normals.detail_normal

    “multiply_01”.r -> blend_normals.detail_normal_weight

    “”normal_blend_weight”.r -> blend_normals.base_normal_weight

  • Connect the blend_normal to the OmniSurfaceBase node

    CONNECT_SKIN_NORMAL

    Connect Geometry Normal and Coat Normal

    blend_normal.out -> OmniSurfaceBase.geometryNormal

    blend_normal.out -> OmniSurfaceBase.coatGeometryNormal

Set Up Diffuse Reflection and Subsurface Scattering

  • Create a Bitmap texture node

  • Set the diffuseReflectionColor texture map file path and set color space to Raw

    Set_DIFFUSE_PATH

    DiffuseReflectionColor Texture Properties

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_skin_diffuseReflectionColor.<UDIM>.exr

    Bitmap file Color Space: raw

  • Connect the texture to the diffuseReflectionColor and subsurfaceScatteringColor slots of the OmniSurfaceBase node

    CONNECT_DIFFUSE_SSS

    Connect to DiffuseReflectionColor and SubsurfaceScatteringColor

  • Create a File Texture node and name it “file_texture_c_skin_specularReflectionColor_subsurfaceScatteringColor_specularReflectionRoughness”

  • Set the file path to the below combined utility map

    COMBINED_MAP_PROP

    Combined Utility Map Properties

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/combined/c_skin_specularReflectionColor-subsurfaceScatteringColor-specularReflectionRoughness.<UDIM>.exr

  • This utility map contains three separate maps, one in each channel:

    Red

    Green

    Blue

    COMBINED_MAP

    Red channel: specular roughness

    Green channel: subsurface weight

    Blue channel: specular weight

    We combined these into one map to save GPU resources

  • Set Subsurface Scattering settings:

    SKIN_SSS_SETTINGS

    Subsurface Properties:

    Enable Subsurface: ON

    Radius(mfp): (0.5955, 0.1525, 0.0664)

    Scale: 0.22

    0.22 means 2.2 millimeters for the scale

    Important

    On the OmniSurfaceBase material, the following inputs:

    • Subsurface Color

    • Subsurface Radius(mfp)

    • Subsurface Scale

    are used to calculate scattering color and absorption color under the hood.

    Subsurface Scale is scene and asset dependent, depending on the scale of the scene and the size of the object.

    By default the value is 1.0 (centimeter), which means the light penetrates the surface to a maximum depth of 10 millimeters.

    The example asset, however, has a height of roughly 25 centimeters. A value of 10 millimeters here is obviously too large for the skin.

    In this case, subsurface scale is set to 0.22, meaning the materials would allow 2.2 millimeters of scattering max.

    CLAIRE_HEAD_HEIGHT

    CLAIRE_SSS_SCALE_100

    CLAIRE_SSS_SCALE_022

    Asset Height

    Scale 1.0

    Scale 0.22

    More detail on Subsurface

  • Connect “file_texture_c_skin_specularReflectionColor_subsurfaceScatteringColor_specularReflectionRoughness”.g -> OmniSurfaceBase.”Subsurface Weight”

    CONNECT_SSS_WEIGHT

    Connect SSS Weight Result to the Material

Setup Specular Reflections

  • Connect “file_texture_c_skin_specularReflectionColor_subsurfaceScatteringColor_specularReflectionRoughness”.r -> OmniSurfaceBase.”Specular Roughness”

  • Create an Add Float Node. The node name defaults to “add”

  • Create a Bitmap texture node, name it “file_texture_c_skin_lipsMask_0_3”, and set the map file path to the same lip mask texture used previously

    LIP_MASK_0.3_PROP

    New Lip Mask, No Invert, 0.3 Brightness

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_skin_lipsMask.<UDIM>.exr

    Brightness: 0.3

    Invert Image: OFF

    Goal is to have more reflection weight on the lips.

  • Connect “file_texture_c_skin_specularReflectionColor_subsurfaceScatteringColor_specularReflectionRoughness”.b -> “add”.a (a is the first input)

  • Connect “file_texture_c_skin_lipsMask_0_3”.r -> “add”.b (b is the second input)

    • The goal is to give the lips area more specular reflection than the rest of the face

  • Connect “add”.output -> OmniSurfaceBase.”Specular Weight”

  • Skin Specular node network

    SKIN_SPEC_NETWORK

    Specular Node Network

Setup Coat Reflections

Note

Coat reflections are used here to add some wetness to the lips.

Coat Weight Setup

  • Create a Multiply Float node, name it “multiply”

    • Connect “file_texture_c_skin_specularReflectionColor_subsurfaceScatteringColor_specularReflectionRoughness”.b -> “multiple”.a

    • Set “multiple” node’s b (second input) value to 0.35

    • Goal is to darken the blue value of the utility map

  • Add the above result together with the skin lip mask texture:

    • Create an Add Float node, name it “add_01”

    • Connect “multiply_float”’.out -> “add_01”.a

    • Connect “file_texture_c_skin_lipsMask_0_3”.r -> “add_01”.a

  • Connect “add_01”.out -> OmniSurfaceBase.”Coat Weight”

  • Coat weight node network:

    COAT_WEIGHT_NETWORK

    Coat Weight Node Network
Coat Roughness Setup

Note

Goal is to set lower roughness values for coat reflections, especially in the lips area.

  • Create a Multiply Float node and name it “multiply_03”

  • Set “multiply_03”.b (second input) value to 0.6

  • Create a new Multiply Float node and name it “multiply_04”

  • Create a new File Texture map using the same lip mask texture, and name it “file_texture_c_skin_lipsMask_0_4_invert”

    LIP_MASK_0.4_PROP

    file_texture_c_skin_lipsMask_0_4_invert properties:

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_skin_lipsMask.<UDIM>.exr

    Brightness : 0.4

    Invert Image: ON

    This mask gives less coat reflection roughness on the lips area

  • Connect file_texture_c_skin_lipsMask_0_4_invert.r -> multiply_04.r (first input)

  • Connect multiply_03.out -> multiply_04.b (second input)

  • Connect multiply_04.out -> OmniSurfaceBase.”Coat Roughness”

    COAT_ROUGHNESS_NETWORK

    Coat Roughness Node Network

Add Makeup

Note

The goal is to add a dark eyeliner material layer on top of the skin material layer

  • Create an “OmniSurfaceBlendBase” node to create the start of the blend material

    BLEND_MTL_NODE_GIF

    Create Blend Material Node

  • Create a “Bitmap texture node”, name it “makeup_mask”, and set the file path to the makeup mask texture

    MAKEUP_MASK_PROP

    Makeup Mask Properties

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_skin_makeupMask.<UDIM>.exr

  • Create a new OmniSurfaceBase node and name it “c_skin_makeup_mtl”

  • Edit the c_skin_makeup_mtl to set the properties of the black eyeliner material

    • Goal is to create a material that looks dark and glossy.

    MAKEUP_MTL_PROP

    Makeup Material Properties:

    diffuse_reflection_weight: 1.0

    diffuse_reflection_color: (0, 0, 0)

    diffuse_reflection_roughness: 0.59

    specular_reflection_weight: 0.51

    specular_reflection_roughness: 0.59

  • Makeup material node network:

    MAKEUP_BLEND_NETWORK

    Blend Makeup Materials Network

    “blend_normals”.out -> “c_skin_makeup_mtl”.geometryNormal *

    “OmniSurfaceBase”.out -> “OmniSurfaceBlendBase”.”Base Material”

    “c_skin_makeup_mtl”.out -> “OmniSurfaceBlendBase”.”Blend Material”

    “makeup_mask”.r -> “OmniSurfaceBlendBase”.”Blending weight”

    “OmniSurfaceBlendBase”.out -> “c_skin_graph”.mdl:surface
*

The makeup layer uses the same geometryNormal as the skin

Eyes Materials

EYES_MTLS_RESULT

The Eyes Materials

Steps

Before

After

Mesh Visibilities

Cornea Material

EYES_CORNEA_BEFORE

EYES_CORNEA_AFTER

Choroid Material

EYES_CHOROID_BEFORE

EYES_CHOROID_AFTER

Lens Material

Tearline Material

EYES_TEARLINE_BEFORE

EYES_TEARLINE_AFTER

Caruncle Material

EYES_CARUNCLE_BEFORE

EYES_CARUNCLE_AFTER

For the eye materials, several “OmniSurface” materials are used instead of MDL graph nodes since we don’t need the power and flexibility of the MDL graph here and these are simpler to work with.

To create an OmniSurface material:

CREATE_OMNISURFACE_MTL

Right Click on Stage View -> Create -> Material -> OmniSurface

Eyes Geometry Visibilities

Turn off visibility for the eyes aqueous meshes because they’re only needed for the Path Tracing Renderer

  • Mesh visibilities off:

    /World/head_hi_model_published/char_model_hi/l_eye_grp_hi/l_aqueous_hi
/World/head_hi_model_published/char_model_hi/r_eye_grp_hi/r_aqueous_hi

    EYES_GEO_VISIBILITY

    Hide Aqueous Meshes

Turn off “cast shadows” for the cornea meshes because RTX Real-Time Rendering doesn’t work well with transparent shadows just yet.

  • Mesh Cast Shadows OFF :

    /World/head_hi_model_published/char_model_hi/r_eye_grp_hi/r_cornea_hi
/World/head_hi_model_published/char_model_hi/l_eye_grp_hi/l_cornea_hi

    EYES_CONREA_CS_OFF

    Cast Shadows: OFF

Eyes Cornea Material

Note

The cornea material is a slightly modified glass material.

  • Create an OmniSurface material and name it “c_cornea_mtl”

  • Assign it to the prims:

    /World/head_hi_model_published/char_model_hi/r_eye_grp_hi/r_cornea_hi
/World/head_hi_model_published/char_model_hi/l_eye_grp_hi/l_cornea_hi

  • Cornea material properties:

    EYES_CONREA_MTL_PROP

    Cornea Material Properties:

    Specular Roughness (specular_reflection_roughness): 0.05

    to create an almost but not quite perfect reflection

    IOR: 1.38

    A value of 1.376 is often quoted in medical publications

    Enable Transmisson: ON

    Transmission weight: 1

Eyes Choroid Material

  • Create an OmniSurface material and name it “c_choroid_mtl”

  • Assign it to the prims:

    /World/head_hi_model_published/char_model_hi/r_eye_grp_hi/r_choroid_hi
/World/head_hi_model_published/char_model_hi/l_eye_grp_hi/l_choroid_hi

  • Choroid material properties:

    EYES_CHOROID_MTL_PROP

    Choroid Material Properties:

    Color image: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_eye_diffuseReflectionColor_rt.1013.exr

    Color Image Color Space: raw

    Base weight: 1

    Specular weight: 0

    Speculare reflection is effectively turned off. All the eyeball reflection colors are calculated from the Eyes_Cornea_Mtl

Eyes Lens Material

Note

The lens material is also a slightly modified glass material.

  • Create an OmniSurface Mtl and name it “c_lens_mtl”

  • Assign it to the prims:

    /World/head_hi_model_published/char_model_hi/r_eye_grp_hi/r_lens_hi
/World/head_hi_model_published/char_model_hi/l_eye_grp_hi/l_lens_hi

  • Lens materials properties:

    EYES_LENS_MTL_PROP

    Lens Material Properties:

    Enable Transmission: ON

    Transmission weight: 1

Eyes Tearline Material

Note

The Tearline Material is essentially a glass-like material with a noisy bump added

  • Create a new material in the MDL Graph Editor and name it “c_tearline_graph”

  • Add a new OmniSurfaceBase material, and connect outputs

  • Assign the material to:

    /World/head_hi_model_published/char_model_hi/l_tearline_hi
/World/head_hi_model_published/char_model_hi/r_tearline_hi

  • “Cast Shadows” OFF on the tearline meshes

    EYES_CONREA_CS_OFF

    Cast Shadows: OFF

  • Set the OmniSurfaceBase material properties:

    EYES_EW_MTL_PROP

    Tearline Material Properties:

    Specular roughtness: 0.05

    Enable Transmission

    Transmission weight: 1

    Transmission color (1, 0.8876, 0.8876)

  • Add a Bitmap texture node and name it “file_texture_c_eye_tearlinesMask”

    • This sets the tearline mask texture opacity, transitioning from center to the edge, fading the visibility of the mesh at the edges.

    EYES_EW_MASK_PROP

    Tearline Mask Properties

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_eye_tearlinesMask.exr

  • Create a Perlin Noise Bump Texture node. The node name defaults to “perlin_noise_bump_texture”

    • This adds a bit of bumpiness to the tearline material

    EYES_EW_NOISE_PROP

    Tearline Noise Properties:

    Bump strength: 0.5

    Tiling: (30, 10, 30)

  • Connect the texture and normal map

    EYES_EW_NETWORK_PROP

    Tearline Opacity and Normal Network:

    “perlin_noise_bump_texture”.out -> OmniSurfaceBase.”Geometry Normal”

    “file_texture_c_eye_tearlinesMask”.r -> OmniSurfaceBase.”Opacity”

Eyes Caruncle Material

Note

The goal is to create a fleshy material. This material uses texture maps but it could also be done with dark red/pink colors and a noise bump.

  • Create a new material in the MDL Graph Editor and name it “c_caruncle_graph”

  • Assign the materials to the prims:

/World/head_hi_model_published/char_model_hi/l_caruncle_hi
/World/head_hi_model_published/char_model_hi/l_caruncle_hi

  • Create an OmniSurfaceBase node, connect to “c_caruncle_graph” inputs

  • Set OmniSurfaceBase Material properties

    EYES_CARUNCLE_MTL_PROP

    Eyes Caruncle Material Properties:

    Specular weight: 0

    Subsurface weight: 0.82

    Subsurface radius color: (0.5274, 0.2435, 0.2280)

    Subsurface scale: 0.12

    1.2 millimeters scale for the caruncle

  • Create a File Texture node, name it “file_texture_c_eye_diffuseReflectionColor” and set the file name path.

  • Set color texture and properties

    EYES_CARUNCLE_TEXTURE_PROP

    Eyes Caruncle Texture Properties

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_eye_diffuseReflectionColor.<UDIM>.exr

  • Connect the “file_texture_c_eye_diffuseReflectionColor” to OmniSurfaceBase

    EYES_CARUNCLE_COLOR_CONNECT

    Eyes Caruncle Color Texture Connects To:

    “file_texture_c_eye_diffuseReflectionColor”.color -> OmniSurfaceBase.diffuseReflectionCOlor

    “file_texture_c_eye_diffuseReflectionColor”.color -> OmniSurfaceBase.subsurfaceScatteringColor

  • Create a Normal map texture node

    • Set the normal map file path. In this case it’s the same file path as the eyes normal map.

    • Connect the normal map output -> OmniSurfaceBase.”Geometry Normal”

    EYES_CARUNCLE_NORMAL_PROP

    Eyes Caruncle Normal Map Properties

    Normalmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_eye_geometryNormal.<UDIM>.exr

Dental And Tongue Materials

Dental Material

DENTAL_MTL_RESULT

The Dental Materials

  • Create a new material in the MDL Graph Editor and name it “c_dental_graph”

  • Assign the material to the prims:

/World/head_hi_model_published/char_model_hi/c_mouth_grp_hi/c_topDenture_hi
/World/head_hi_model_published/char_model_hi/c_mouth_grp_hi/c_bottomDenture_hi

  • Create an OmniSurfaceBase node, connect to outputs

  • Create a File texture node and name it “file_texture_c_dental_diffuseReflectionColor”

  • Set the dental diffuse texture file map path

    DENTAL_DIFFUSE_PROP

    Dental Diffuse Texture Properties:

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_dental_diffuseReflectionColor.<UDIM>.exr

  • Create a new Bitmap file Texture node and name defaults to “file_texture”

    • Set the dental ambient occlusion texture map file path

    DENTAL_AO_PROP

    Dental Ambient Occlusion Texture

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_dental_ambientOcclusion.<UDIM>.png

    Note

    Ambient occlusion maps are used to add some shadow to the dental meshes. This minimized the number of shadow samples needed inside the mouth.

  • Create a blend color node and name it “blend_colors”,

  • Connect the above two texture nodes to the blend colors node

    DENTAL_BLEND_PROP

    Blend Colors Node Properties

    “tongue_diffuse_texture”.color -> “blend_colors”.”Color 1”

    “file_texture”.color -> “blend_colors”.”Color 2”

    Blend weight: 0.3

    “blend_colors”.color -> OmniSurfaceBase.diffuseReflectionColor

    “blend_colors”.color -> OmniSurfaceBase.subsurfaceScatteringColor

  • Create a Normal map texture node and set the normal map texture file map path

    DENTAL_NORMAL_PROP

    Dental GeometryNormal Texture

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_dental_geometryNormal.<UDIM>.exr

    • Connect the normal texture to the geometery normal slot of the material

  • Set OmniSurfaceBase Material properties

    DENTAL_MTL_PROP

    Dental Material Properties:

    Specular Roughness: 0.08

    Specular IOR: 1.4

    Enable Subsurface: ON

    Subsurface Weight: 1

    Subsurface Color: connected diffuse texture

    Subsurface Radius Color: (0.60828, 0.38164, 0.29058)

    Subsurface Scale: 0.225

    Coat Weight: 0.6

    Coat Roughness: 0.112

    Coat IOR: 1.5

Tongue Material

Note

In this asset the tongue and dental meshes share the same diffuse and normal maps. Your setup may be different.

The tongue material uses a similar ambient occlusion setup as the rest of the mouth

  • Create a new material in the MDL Graph Editor and name it “c_tongue_graph”

  • Assign the material to the prims:

/World/head_hi_model_published/char_model_hi/c_mouth_grp_hi/c_tongue_hi

  • Create an OmniSurfaceBase node, connect to outputs

  • Create a Bitmap file Texture and name it “tongue_normal_texture”

    • Use the same geometryNormal texture map file path as the dental material

    TONGUE_NORMAL_PROP

    Dental Normal Texture

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_dental_geometryNormal.<UDIM>.exr

    “tongue_normal_texture”.color -> OmniSurfaceBase.geometryNormal

  • Create a Bitmap file Texture node and name it “tongue_diffuse_texture”

    • Use the same diffuseReflectionColor textures as the dental material but with the brightness toned down.

    TONGUE_DIFFUSE_PROP

    Tongue Diffuse Texture

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_dental_diffuseReflectionColor.<UDIM>.exr

    Brightness: 0.73

    Make it a bit darker by setting the Brightness to 0.73

  • Create a Bitmap file Texture node and name it “tongue_ao_texture”

    • Set the ambient occlusion texture map file path

    TONGUE_AO_PROP

    Tongue Ambient Occlusion Texture

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_tongue_ambientOcclusion.1003.exr

  • Create a blend color node and name it “tongue_blend_colors1”

    TONGUE_DIFFUSE_BLEND_PROP

    Tongue Blend Colors 1

    “tongue_diffuse_texture”.color -> “tongue_blend_colors1”.”Color 1”

    Color 2: (0.19426751, 0.039595928, 0.039595928)

    Blend weight: 0.31

  • Create a new blend color node and name it “tongue_blend_colors2”

    TONGUE_AO_BLEND_PROP

    Tongue Blend Colors 2

    “tongue_blend_colors1” -> “tongue_blend_colors2”.”Color 1”

    “tongue_ao_texture” -> “tongue_blend_colors2”.”Color 2”

    Blend weight: 0.2

  • Connect “tongue_blend_colors2” to “OmniSurfaceBase”

    • “tongue_blend_colors2” -> “OmniSurfaceBase”.diffuseReflectionColor

    • “tongue_blend_colors2” -> “OmniSurfaceBase”.subsurfaceScatteringColor

  • Set the OmniSurfaceBase materials properties

    TONGUE_MTL_PROP

    Tongue Material Properties:

    Specular Roughness: 0.12

    Enable Subsurface, weight 1

    Subsurface radius color: (0.5828, 0.2923, 0.27656)

    Subsurface scale: 0.2

  • Tongue Node Network

    TONGUE_NODE_NETWORK

    Tongue Node Network

Hair Materials

Note

Omniverse has 2 UV sets for hair:

  1. uvset0, u value interpolates from 0 at the root to 1 at the tip

    HAIR_UV0_VIS

    Hair UV0 visualized. Color is red at the root, blue at the tip

  2. uvset1, based on the head uv’s

    HAIR_UV1_VIS

    Hair UV1 visualized. Color is based on uv’s from the head mesh

More detail on exporting hair with UVs here .

Note

The hair material presets shipped with OmniHairBase provide a good starting point.

Presets can be accessed when creating OmniHair materials.

For Claire, the majority of the hair materials have only slightly different Melanin and Melanin Redness(Pheomelanin) values.

  • To create hair materials with a preset:

    • Right Click on Stage view -> Create -> Material -> OmniHairPresets -> Pick one from the options

    HAIR_MTL_PRESETS

    Preset OmniHair Materials

  • To pick melanin preset values:

    • Pick from the “Melanin Presets” dropdown options on the OmniHairBase material

    MELANIN_PRESETS

    Preset OmniHair Melanin Values

Eyebrow Material

Note

The Eyebrow Material is the default OmniHair Material with the Melanin value set to 1 - all black

EYES_BROW_RESULT

The Eyebrow Materials

EYES_BROW_MTL_PROP

Eyebrow Materials Properties:

Melanin: 1

All black in color

Specular Roughness: 0.15

A bit more roughness than the default value

Eyelash Material

Note

The Eyelash Material is the default OmniHair Material with the Melanin value set to 0.94

EYES_LASH_RESULT

The Eyelash Material

EYES_LASH_MTL_PROP

Eyelash Material Properties

Melanin: 0.94

Dark color but a bit lighter than the eyebrows

Facial Hair Material

Note

The Facial Hair Material is the default OmniHair Material with the Melanin value set to 0.7

FACIAL_HAIR_RESULT

The Facial Hair Material, Circled in Red

FACIAL_HAIR_MTL_PROP

Facial Hair Material Properties:

Melanin: 0.7

Baby Hair Material

Note

The Baby Hair is the thin hair on Claire’s forehead defining the hairline.

BABY_HAIR_RESULT

The Baby Hair Material

BABY_HAIR_MTL_PROP

Baby Hair Material Properties

Melanin: 0.7

Hair color

Anistropic Roughness: ON

Azimuthal Roughness: 0.13

More detail on Azimuthal Roughness

Main Hair Material Graph

The Main Hair Material graph is more complex than the other hair materials. It breaks down into the following steps:

  • Set a color gradient from hair root to tip (uvset0)

  • Blend in noise colors based on the head UV’s (uvset1)

  • Set the result to hair base color

  • Set diffuse color to a noise texture

    • adds some dryness to the hair here and there. Higher diffuse values create dryer looking hair.

  • Add noise to the hair geometryNormal

  • Additional settings on OmniHairBase material

MAIN_HAIR_RESULT

The Main Hair Material
Detailed Steps

  • In the MDL Graph Editor, create an OmniHairBase material and name it “c_hair_main_graph”

    OMNIHAIRBASE_NODE_GIF

    Create OmniHairBase Node

  • Connect outputs

  • Create a texture coordinate 2d node. The node name defaults to “texture_coordinate_2d”

    • set it to use index 0 to access uvset0.

  • Create a float2.X node. The node name defaults to “x”

  • Connect “texture_coordinate_2d”.out -> “x”.a, to access the U value of the uvset0.

  • Create a power node and name it “pow”,

  • Connect “x”.out -> “pow”.a (“a” means first input of the power node)

  • Set the “pow”.b (power value) to 2.5

    • The goal is to be able to squeeze/expand the u value range. A bigger value gives a tighter root to tip color range

    HAIR_U_POW1

    Power Value: 1

    HAIR_U_POW2.5

    Power Value: 2.5

  • Create a Bitmap Texture node and name it “file_texture_c_hair_noise”

    • Load a noisy texture map and use the second uvset:

    HAIR_NOISE_TEXTIRE_PROP

    Hair Noise Texture Properties:

    Bitmap file: https://omniverse-content-production.s3.us-west-2.amazonaws.com/Samples/Examples/2023_1/Rendering/Claire/sourceimages/claire_rt/c_hair_noise.png

    UV Space Index: 1

    “1” means second uvset

    Brightness: 0.36

  • Create a Lerp Color node. The node name defaults to “lerp”

    • Set the lerp node to interpolate between the above noise texture and a pink color.

    HAIR_LERP_NOISE_RED_PROP

    Lerp Node Properties:

    Connect “file_texture_c_hair_noise”.color -> “lerp”.a

    b: (0.8991, 0.6075, 0.5312)

    Connect “pow”.out -> “lerp”.I (“I” means interpolation value)

  • Create two other worley noise texture nodes and blend in the above lerp result with two other colors

    W_NOISE_A

    W_NOISE_B

    Name: “worley_noise_texture”

    Color 1 connected to lerp node

    Cell type: crystal_cells

    Cell shape: crystal_cells

    Color 2: (0.4357, 0.0843, 0.7695)

    Lower threshold: 0.87

    Upper threshold: 0.98

    UV space index: 1

    Tiling: 6000

    Name: “worley_noise_texture_01”

    Color 1: connected to worley_noise_a

    Cell type: crystal_cells

    Cell shape: crystal_cells

    Color 2: (0.192, 0.93, 0.04)

    Lower threshold: 0.85

    Upper threshold: 0.91

    UV space index: 1

    Tiling: 6000

  • Connect “worley_noise_texture_01”.color -> OmniHairBase.”base color”

  • Connect “pow”.out -> OmniHairBase.”Base Color Weight”

  • Add a multiply color node. The node name defaults to “multiply”

    • Connect “file_texture_c_hair_noise”.color -> “multiply”.a (“a” means first color input)

    • Set “multiply” node’s second input color to dark red, e.g (0.1338, 0.0817, 0.0341)

  • Connect “multiply”.out -> OmniHairBase.”Diffuse Color”

  • Create a Perlin noise bump texture node. The node name defaults to “perlin_noise_bump_texture”

    • This adds a subtle normal variation from root to tip on the hair curves

    P_NOISE_BUMP_PROP

    Perlin Noise Bump Node Properties:

    Bump Strength : 2

    Upper threshold: 0.64

    Levels: 3

    Connect “perlin_noise_bump_texture”.out -> OmniHairBase.”geometryNormal”

  • Set OmniHairBase material properties:

    MAIN_HAIR_MTL_PROP

    Main Hair Material Properties

    Base Color: Connected to Noise Color Input

    Specular Roughness: 0.19

    Melanin: 1

    Anistropic Roughness: ON

    Azimuthal Roughness: 0.13

    Diffuse Color: Connected to Noise Color node Input

  • The main hair node graph network should look similar to this:

    HAIR_MAIN_NETWORK

    “c_hair_main_graph” network

Setup Post Processing and Render Settings

Setup Tone Mapping

Note

For this asset we preferred not to use any tone mapping and instead applied our own color corrections in the post processing settings.

  • Set Render Setting->Post Processing-> Tone Mapping-> Tone Mapping Operator to “Linear(Off)”

    Tonemapping_Linear

    Tone Mapping Operator : Linear(Off)

    Means no tone mapping is used

Post Processing

Note

The goal of this section is to:

  • Add some contrast to the final render as well as some subtle real-life imperfections including chromatic aberration, vignetting, and bloom

Not that post processing settings are subjective, based on your preferences. These values are only suggestions. Experiment!

  • Before and After

ALL_MTLS_RESULT_SM

ALL_TOGETHER_SM

Before

After

PP_CC

Color Correct Properties

Gamma: (0.91066283, 0.9106537, 0.9106537)

Saturation: (0.9267516, 0.87448156, 0.8500142)

PP_CG

Color Grading Properties

Black Point: (0.051543683, 0.06724222, 0.105095565)

white Point: (0.9798271, 0.9798173, 0.9798173)

Lift: (0.06369424, 0.0636936, 0.0636936)

Gain: (0.96496814, 0.9649585, 0.9649585)

Offset: (0.0159234, 0.015923483, 0.01592356)

Gamma: (0.9267516, 0.9267423, 0.9267423)

PP_CA

Chromatic Aberration Properties

Strength Red: -0.01

Strength Green: 0

Strength Blue: 0.01

Algorithm Red/Green/Blue: Barrel

PP_BLOOM

Bloom Properties

Scale: 0.1

PP_VA

Vignetting Properties

Enable Vignetting: ON

Vignetting Size: 106.08

Vignetting Strength: 0.02

Enable Film Grain: OFF

 
#usda 1.0
(
    customLayerData = {
        dictionary renderSettings = {
            bool "rtx:ambientOcclusion:enabled" = 0
            int "rtx:domeLight:upperLowerStrategy" = 3
            bool "rtx:hydra:materialSyncLoads" = 0
            bool "rtx:hydra:mdlMaterialWarmup" = 0
            bool "rtx:indirectDiffuse:enabled" = 0
            int "rtx:indirectDiffuse:updateSampleCount" = 0
            double "rtx:lightspeed:NRD_Common:denoisingRange" = 100000
            double "rtx:lightspeed:NRD_Common:disocclusionThreshold" = 0.00005
            int "rtx:lightspeed:NRD_ReLAX:diffuseFastHistoryFrames" = 2
            int "rtx:lightspeed:NRD_ReLAX:diffuseHistoryFrames" = 15
            double "rtx:lightspeed:NRD_ReLAX:diffusePhiLuminance" = 1
            int "rtx:lightspeed:NRD_ReLAX:specularFastHistoryFrames" = 0
            int "rtx:lightspeed:NRD_ReLAX:specularHistoryFrames" = 0
            bool "rtx:materialDb:syncLoads" = 0
            bool "rtx:multiThreading:enabled" = 1
            bool "rtx:post:chromaticAberration:enabled" = 1
            int "rtx:post:chromaticAberration:modeB" = 1
            int "rtx:post:chromaticAberration:modeG" = 1
            int "rtx:post:chromaticAberration:modeR" = 1
            double "rtx:post:chromaticAberration:strengthB" = 0.01
            double "rtx:post:chromaticAberration:strengthG" = 0
            double "rtx:post:chromaticAberration:strengthR" = -0.01
            bool "rtx:post:colorcorr:enabled" = 1
            float3 "rtx:post:colorcorr:gamma" = (0.91066283, 0.9106537, 0.9106537)
            float3 "rtx:post:colorcorr:saturation" = (0.9267516, 0.87448156, 0.8500142)
            float3 "rtx:post:colorgrad:blackpoint" = (0.051543683, 0.06724222, 0.105095565)
            float3 "rtx:post:colorgrad:contrast" = (1, 0.99999, 0.99999)
            bool "rtx:post:colorgrad:enabled" = 1
            float3 "rtx:post:colorgrad:gain" = (0.96496814, 0.9649585, 0.9649585)
            float3 "rtx:post:colorgrad:gamma" = (0.9267516, 0.9267423, 0.9267423)
            float3 "rtx:post:colorgrad:lift" = (0.06369424, 0.0636936, 0.0636936)
            float3 "rtx:post:colorgrad:offset" = (0.0159234, 0.015923483, 0.01592356)
            float3 "rtx:post:colorgrad:whitepoint" = (0.9798271, 0.9798173, 0.9798173)
            int "rtx:post:dlss:execMode" = 0
            double "rtx:post:dof:fNumber" = 20
            double "rtx:post:dof:subjectDistance" = 220
            double "rtx:post:histogram:whiteScale" = 17.639999605715275
            bool "rtx:post:lensFlares:enabled" = 1
            double "rtx:post:lensFlares:flareScale" = 0.1
            double "rtx:post:lensFlares:haloFlareWeight" = 0.01
            double "rtx:post:tonemap:dither" = 0.01
            int "rtx:post:tonemap:op" = 1
            double "rtx:post:tvNoise:colorAmount" = 0.9999999776482582
            bool "rtx:post:tvNoise:enableFilmGrain" = 0
            bool "rtx:post:tvNoise:enableVignetting" = 1
            bool "rtx:post:tvNoise:enabled" = 1
            double "rtx:post:tvNoise:grainAmount" = 0.03999999910593033
            double "rtx:post:tvNoise:lumAmount" = 0.549999987706542
            double "rtx:post:tvNoise:vignettingSize" = 106.07999801635742
            double "rtx:post:tvNoise:vignettingStrength" = 0.019999999552965164
            bool "rtx:raytracing:cached:enabled" = 0
            bool "rtx:raytracing:fractionalCutoutOpacity" = 1
            bool "rtx:raytracing:hair:fixAliasing" = 1
            bool "rtx:raytracing:subsurface:enabled" = 1
            int "rtx:raytracing:subsurface:maxSamplePerFrame" = 16
            bool "rtx:raytracing:subsurface:transmission:ReSTIR:enabled" = 1
            int "rtx:raytracing:subsurface:transmission:bsdfSampleCount" = 4
            bool "rtx:raytracing:subsurface:transmission:denoiser:enabled" = 0
            int "rtx:raytracing:subsurface:transmission:perBsdfScatteringSampleCount" = 6
            bool "rtx:realtime:mgpu:enabled" = 0
            double "rtx:reflections:maxRoughness" = 0.4
            int "rtx:shaderDb:cachePermutationIndex" = -1
            bool "rtx:shaderDb:driverAppShaderCacheDirPerDriver" = 0
            bool "rtx:shadows:constantSeed" = 0
            bool "rtx:shadows:denoiser:quarterRes" = 0
            bool "rtx:shadows:enableSpatialFiltering" = 0
            int "rtx:shadows:sampleCount" = 2
            bool "rtx:shadows:stratifySamples" = 0
        }
    }
)

Additional Render Settings

Note

Several Real-Time Rendering settings are set to optimize the balance between performance and quality.

The RTX Real-Time Renderer is still being actively developed. Some of the settings covered here may be deprecated once DLSS-D is ready. We’ll keep this section updated when things change.

Setting

Value

Notes

Ray Tracing->NVIDIA DLSS->Frame Generation

vary

Frame Generation uses deep learning technology to generate a higher frame rate than what’s actually rendered.

Ray Tracing->Direct Lighting->Non-Sampled Lighting Settings->Shadow Samples Per Pixel

2

Trades render time for more shadow samples, providing a better input for the denoiser to work with.

Ray Tracing->Direct Lighting->Non-Sampled Lighting Settings->Low Resolution Shadow Denoiser

OFF

Low resolution shadows reduce shadow quality and detail. Enabling this setting can provide extra performance but for our high quality digital human head scene we turned it off.

Ray Tracing->Indirect Diffuse Lighting->Ambient Occlusion

OFF

Ambient Occlusion is an artistic way to add shadowing to the nooks and crannies of geometry but we decided to turn it off for this scene.

Ray Tracing->Reflectons-> Roughness Cache Threshold

0.4

Roughness threshold above which reflections are approximated. Higher values result in better quality but worse performance. We chose an in-between value which we thought optimal for the scene.

Ray Tracing->Translucency->Fractional Cutout Opacity

ON

We used fractional opacity to render the eyes.

Ray Tracing->Subsurface Scattering->Max Samples Per Frame

16

This is a scene-dependent parameter. Higher samples didn’t result in obvious quality improvement for this particular scene.

Ray Tracing->Subsurface Scattering->Transmission->BSDF Sample Count

Ray Tracing->Subsurface Scattering->Transmission->Denoiser

Ray Tracing->Subsurface Scattering->Transmission->Samples per BSDF Sample

4

OFF

6

We increased the default sample count for transmission and disabled the denoiser to get a better translucency effect for subsurface materials while retaining sharp details

Ray Tracing->Subsurface Scattering->Transmission->Sample Guiding

ON

Sample guiding helps the renderer acquire better samples for subsurface. It’s particularly useful in creating a more noise-free result without the denoiser enabled