Omni PhysX Zero Gravity

Overview

This extension provides a toolbar button to enable “Zero Gravity” for physically accurate placement of geometry in a USD stage.

Zero Gravity

Press the “Zero Gravity” toolbar button or the ‘X’ key press to enable.

Set Markers on Geometry

With “Zero Gravity” enabled, use the right mouse click context menu, you can “Set Dynamic Marker” or “Set Static Marker” with different levels of precision to define the collision approximations. You can also “Clear Marker” to allow the geometry to not be interactable with physics.

Translate or Rotate Geometry

With “Zero Gravity” enabled, use the standard Transform Gizmo for translating or rotating objects. This will move geometry with physical accurate responsiveness to your edits. You must first set objects to be wither static or dynamic using the right click context menu options on selected objects. You can also undo/redo any changes you make.

Drop Geometry

With “Zero Gravity” enabled, you can hold the ‘END’ key to drop geometry with gravity applied. Dropped objects will fall and collide with other geometry that have physics set on them.

Drag Geometry

With “Zero Gravity” enabled, you can hold SHIFT + mouse cursor drag to arbitrarily drag them around the stage. Dragged objects will physically interact with other objects that have physics set on them.

Saving Zero Gravity Mode Changes

Any physics markers set in “Zero Gravity” are saved USD stage in meta-data. Saving your USD will not persist the actual physics applied. However, it will save the new transformations of any geometry that has been moved around the stage.