public Matrix4x4[] ComputeInstanceMatrices(Scene scene, string primPath)
{
var prim = scene.GetPrimAtPath(primPath);
var pi = new pxr.UsdGeomPointInstancer(prim);
var xforms = new pxr.VtMatrix4dArray();
pi.ComputeInstanceTransformsAtTime(xforms, scene.Time == null ? pxr.UsdTimeCode.Default() : scene.Time, 0);
// Slow, but works.
var matrices = new Matrix4x4[xforms.size()];
for (int i = 0; i < xforms.size(); i++)
{
matrices[i] = UnityTypeConverter.FromMatrix(xforms[i]);
}
return(matrices);
}
public static void CreatePointInstancerManualTest()
{
var scene = USD.NET.Scene.Create();
var stageWeakRef = new pxr.UsdStageWeakPtr(scene.Stage);
var pi = pxr.UsdGeomPointInstancer.Define(stageWeakRef, new pxr.SdfPath("/Instancer"));
var cube = pxr.UsdGeomCube.Define(stageWeakRef, new pxr.SdfPath("/Instancer/Cube"));
// The cube is the only prototype.
pi.CreatePrototypesRel().AddTarget(cube.GetPath());
// Create three instances of the cube (proto index=0).
var intArray = new pxr.VtIntArray(3, 0);
pi.CreateProtoIndicesAttr().Set(intArray);
var mesh = new pxr.UsdGeomMesh();
var meshSamples = new USD.NET.Unity.MeshSample[0];
// Create three positions.
var vec3fArray = new pxr.VtVec3fArray(3);
vec3fArray[0] = new pxr.GfVec3f(-2.5f, 0, 0);
vec3fArray[1] = new pxr.GfVec3f(0, 0, 0);
vec3fArray[2] = new pxr.GfVec3f(2.5f, 0, 0);
pi.CreatePositionsAttr().Set(vec3fArray);
scene.Stage.Export("D:\\instancer.usda");
//
// Compute the root transform for each instance.
//
var xforms = new pxr.VtMatrix4dArray(3);
pi.ComputeInstanceTransformsAtTime(xforms, time: 1.0, baseTime: 0.0);
for (int i = 0; i < xforms.size(); i++)
{
Console.WriteLine(xforms[i]);
}
}