I have some custom plants intermixed with stock VW plants(the ones in the rightmost rectangle)   When I export them to TwinMotion using C4D, note how some of the object have a black background where it should be transparent.   The image props were constructed by masking a photograph in Photoshop and/or Affinity Photo to create a texture and saved as PNG with a transparent background.  The imageprops were created in VW by using the aforementioned texture file with