Localyzed transparency

Hi, I am new in Blender, I come from Lightwave and in this software there’s a way to relate any gradient to a null object or empty object. What I’m trying to do is to create a localyzed transparency into a human body and, also, to be able to animate it (moving the empty object). For example I’d need to see the human body as normal, but a small transparency into the chest would allow me to show the heart.

Thank you so much.

F.

Cycles or BlenderInternal? there’re different solutions for that purpose…

I do this in the compositor with an animated mask:
->render out the body scene twice, once with skin, once with the organs behind, then create a mask for the alpha and animate it as desired for blending the 2 image sequences…

Thanks guys. Mobimo, the postproduction way is what I’m trying to avoid, just to learn the 3D way :slight_smile: Secrop, I’d like to do it into cycles. Thanks again.