bool is_back_facing(int tid)
{
Vector3d n = PreviewMesh.GetTriNormal(tid);
Vector3d c = PreviewMesh.GetTriCentroid(tid);
return((c - cameraFrameL.Origin).Dot(n) > -0.1);
}
public bool FindHitTriangle(Ray3f sceneRay, bool snap_to_center, ref Frame3f hitFrameS, ref int hitTID)
{
Ray3f objRay = SceneTransforms.SceneToObject(Target, sceneRay);
hitTID = PreviewSpatial.FindNearestHitTriangle(objRay);
if (hitTID == DMesh3.InvalidID)
{
return(false);
}
if (allow_backface_hits == false && is_back_facing(hitTID))
{
return(false);
}
var intr = MeshQueries.TriangleIntersection(PreviewMesh, hitTID, objRay);
if (snap_to_center)
{
Frame3f hitFrameL = new Frame3f(PreviewMesh.GetTriCentroid(hitTID), PreviewMesh.GetTriNormal(hitTID));
hitFrameS = SceneTransforms.ObjectToScene(previewSO, hitFrameL);
}
else
{
Vector3f hitPoint = objRay.PointAt((float)intr.RayParameter);
Frame3f hitFrameL = new Frame3f(hitPoint, PreviewMesh.GetTriNormal(hitTID));
hitFrameS = SceneTransforms.ObjectToScene(previewSO, hitFrameL);
}
return(true);
}
