// matrix to transform point on a primitive from bake space into space of the shape
static float4x4 GetPrimitiveBakeToShapeMatrix(
float4x4 localToWorld, float4x4 shapeToWorld, ref float3 center, ref EulerAngles orientation, float3 scale, int3 basisPriority
)
{
if (
basisPriority.x == basisPriority.y ||
basisPriority.x == basisPriority.z ||
basisPriority.y == basisPriority.z
)
{
throw new ArgumentException(nameof(basisPriority));
}
var localToBasis = float4x4.TRS(center, orientation, scale);
// correct for imprecision in cases of no scale to prevent e.g., convex radius from being altered
if (scale.Equals(new float3(1f)))
{
localToBasis.c0 = math.normalizesafe(localToBasis.c0);
localToBasis.c1 = math.normalizesafe(localToBasis.c1);
localToBasis.c2 = math.normalizesafe(localToBasis.c2);
}
var localToBake = math.mul(localToWorld, localToBasis);
if (localToBake.HasNonUniformScale() || localToBake.HasShear())
{
// deskew second longest axis with respect to longest axis
localToBake[basisPriority[1]] =
DeskewSecondaryAxis(localToBake[basisPriority[0]], localToBake[basisPriority[1]]);
// recompute third axes from first two
var n2 = math.normalizesafe(
new float4(math.cross(localToBake[basisPriority[0]].xyz, localToBake[basisPriority[1]].xyz), 0f)
);
localToBake[basisPriority[2]] = n2 * math.dot(localToBake[basisPriority[2]], n2);
}
var bakeToShape = math.mul(math.inverse(shapeToWorld), localToBake);
// transform baked center/orientation (i.e. primitive basis) into shape space
orientation.SetValue(
quaternion.LookRotationSafe(bakeToShape[basisPriority[0]].xyz, bakeToShape[basisPriority[1]].xyz)
);
center = bakeToShape.c3.xyz;
return(bakeToShape);
}
