Basic Lighting Question

[RoyBU]

I am trying to get the effect of a light shining through a doorway into a very large dark room. The doorway won't be visible, but that seemed like the easiest way to change the light cone's shape from a circle to a rectangle. The problem I'm having is that if I turn volumetric on for the light, then the light rays are visible as they cut through the air in the dark room (which is what I want), but the doorway does not block any of the light. If I turn on shadows for the light, then the doorway blocks the light as I want but now the light cone is no longer visible. How do I get both shadows and volumetrics to work at the same time?

[J.Bruce]

http://www.hash.com/forums/index.php?showtopic=13456&hl=

 

That might help. If the wall that your door is cut out of is only one plane / patch then the volumetrics won't read it as a solid object (to my understanding). Therefore, if you make the wall an actual wall it should react to the lights a little better. Hope that helps.

 

J

[RoyBU]

Thanks, that thread is really helpful.

[RoyBU]

As a follow-up, I have been experimenting with lighting and thought I had discovered that volumetric would not work when shadows were turned on. In fact, I was doing a one-frame render to include as an attachment to a posting about this "problem" when I discovered that when I did the render-to-disk the volumetric DOES work with shadows, even though it would not show up in quick (shift-Q) render. So I am glad to finally understand this, but am left wondering why volumetric doesn't show up in quick render with shadows turned on.

[RoyBU]

OK, now I'm even more confused. As I said in my above post, I rendered out a simple scene using volumetric (on a klieg light) and shadows and both worked as expected even though in quick render the volumetric did not show up. After posting the above, I went back to experimenting and discovered that now, post render, volumetric DOES show up in quick render. Wondering if I had changed a setting and not realized it, I opened another project (the one I'm actually trying to use volumetric in) and did a quick render. As before, volumetric did not show up even though it was on. Then I rendered one frame to disk and, as with my simple test project, volumetric appeared in the render. Then I went back to my choreography, did a quick render and - lo and behold! - now the volumetric shows up in quick render. However, after saving, exiting A:M, and then restarting and reopening my project, it's back to where I was before -- volumetric will only show up in quick render if shadows are turned off. Am I missing something here?