I am new user here so sorry if this issue is already solved earlier. I have no issues to use png texture with out background on flat surface. This Kettlebell surface just wont work.
Hope there is easy way to solve this but I just cant figure out .
You can UV mapping (SketchUV) the sphere and use a Blend material in V-ray. But also need to prepare the logo texture before inserting (to wrap the sphere exactly, including distortions)