Here is a Volume Render result, how to interact with other 3D object

Question

I've implemented the volume render using ray-casting in CUDA. Now I need to add other 3D objects (like 3D terrain in my case) in the scene and then make it interact with the volume-render result. For example, when I move the volume-render result overlapping the terrain, I wish to modulate the volume render result such as clipping the overlapping part in the volume render result.

However, the volume render result comes from a ray accumulating color, so it is a 2D picture with no depth. So how to implement the interaction makes me very confuse. Somebody can give me a hint?

Answer 1

Actually, I think the result of ray-casting is a 2D image, it cannot interact with other 3D objects as the usual way. So my solution is to take the ray-casting 2D image as a texture and blend it in the 3D scene. If I can control the view position and direction, we can map the ray-casting result in the exact place in the 3D scene. I'm still trying to implement this solution, but I think this idea is all right!

Answer 2

First you render your 3D rasterized objects. Then you take the depth buffer and use it as an additional data source in the volume raycaster as additional constraint on the integration limits.