Hi MostHost!
Thanks a lot for your answer! Before seeing this response, I tried to render the mask directly (instead of sampling the local-bone positions from a texture, I used the sphere mask in the unwrapping step with the original positions). The render target is now updated using the “additive” mode from the scene capture component. However, I’m still getting seams (but a lot less evident as before).
I’ll check what you said and see if it improves. Lots of thanks!