usdgeom-extent#
Code |
VG.002 |
---|---|
Validator |
|
Compatibility |
openusd |
Tags |
🚀 |
Summary#
Boundable geometry primitives should have valid extent values.
Description#
The extent of a geometry primitive represents its bounding box in local space. For time-varying geometry, the extent must be computed at each time sample where the geometry changes, but should only be authored when it differs from the previous time sample’s extent to minimize data storage.
Why is it required?#
Performance optimization in rendering
Performance optimization in other operations which perform spatial queries
Examples#
#usda 1.0
# Invalid: Incorrect extent on static geometry
def Mesh "MeshWithIncorrectExtent" {
point3f[] points = [(0,0,0), (1,1,1)]
float3[] extent = [(-1,-1,-1), (1,1,1)]
}
# Invalid: Missing extent on time-varying geometry
def Mesh "MeshWithoutExtent" {
float[] times = [0, 1]
point3f[] points.timeSamples = {
0: [(0,0,0), (1,1,1)],
1: [(0,0,0), (2,2,2)]
}
# Missing extent attribute
}
# Valid: Extent authored only when it changes
def Mesh "MeshWithExtent" {
float[] times = [0, 1]
point3f[] points.timeSamples = {
0: [(0,0,0), (1,1,1)],
1: [(0,0,0), (2,2,2)]
}
float3[] extent.timeSamples = {
0: [(0,0,0), (1,1,1)], # Initial extent
1: [(0,0,0), (2,2,2)] # Extent changes with geometry
}
}
How to comply#
Author extent for boundable geometry
For time-varying geometry:
Compute extent at each time sample of attributes which may influence the extent. See
ComputeExtent
andComputeExtentFromPlugins
in UsdGeomBoundable for more information.Only author when value changes