bool PxrUsdMayaTranslatorXformable::ConvertUsdMatrixToComponents(
const GfMatrix4d &usdMatrix,
GfVec3d *trans,
GfVec3d *rot,
GfVec3d *scale)
{
GfVec3d rotation, scaleVec, scaleOrientation;
_MatrixToVectorsWithPivotInvariant(
usdMatrix,
//const TransformRotationOrder rotationOrder, XYZ
GfVec3d(0,0,0), // const GfVec3d pivotPosition
GfVec3d(0,0,0), // const GfVec3d pivotOrientation
trans,
&rotation,
&scaleVec,
&scaleOrientation);
for (int i=0; i<3; ++i) {
// Note that setting rotation via Maya API takes radians, even though
// the MEL attribute itself is encoded in degrees. #wtf
(*rot)[i] = GfDegreesToRadians(rotation[i]);
(*scale)[i] = scaleVec[i];
}
return true;
}
void
GfCamera::SetPerspectiveFromAspectRatioAndFieldOfView(
float aspectRatio,
float fieldOfView,
GfCamera::FOVDirection direction,
float horizontalAperture)
{
// Perspective
_projection = Perspective;
// Set the vertical and horizontal aperture to achieve the aspect ratio
_horizontalAperture = horizontalAperture;
_verticalAperture = horizontalAperture /
(aspectRatio != 0.0 ? aspectRatio : 1.0);
// Pick the right dimension based on the direction parameter
const float aperture =
(direction == GfCamera::FOVHorizontal) ?
_horizontalAperture : _verticalAperture;
// Compute tangent for field of view
const float tanValue = tan(0.5 * GfDegreesToRadians(fieldOfView));
if (tanValue == 0) {
// To avoid division by zero, just set default value
_focalLength = 50.0;
return;
}
// Do the math for the focal length.
_focalLength =
aperture * GfCamera::APERTURE_UNIT /
( 2 * tanValue) / GfCamera::FOCAL_LENGTH_UNIT;
}
