You may have read that the World Volume puts a volume effect in the whole world space and so it tends not to be useful for daylight because even at low densities it blocks all the light. This is true for a simple setup. But it turns out it is quite possible to restrict the area were the volume is defined in the world space and to define density and density variations within that space.
I was doubtful myself when I experimented with this but it works. I will supply the blend file below for anyone to experiment with.
What this World Does.
- We define a band in the z direction - this will be a mask for the area were the volume will be applied.
- We calculate distance from origin in xy and means o control this distance as a factor for density.
- We add facility for noise variation on the defined volume z band and on the final defined density distribution.
- The world can then be given a background surface eg sky.
The result is that it is quite possible to define a slice in world space where the volume rendering will take place.
Im sure much much more control over were density is rendered could be achieved. essentially im just proving to myself here that it can be done as I hadnt come across anything which showed that it could be done or how to do it.
I hope this might be of interest to someone.
The blend is setup with all the nodes and the world background setup as described. The volume shows up in camera view but the volume doesnt show trying other views.
There is a ground plane and Ive put a block at some distance from the camera. The block is there so the renderer isnt searching the volume at too long distances. It will render if you remove or hide the cube but the render is much slower. Ideally I want to develop the nodes so that I can cut the volume off also at a certain distances from the camera.
No fancy visual here this is simply about controlling and defining areas in the world volume. It may not even be that practically useful. But who said experiments had to be useful?