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Old 13-04-2004, 02:41 AM   #1
Fade
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Question Volumetric light problem

I have a small room with a window, on the outside of the window i've set up a light facing the window and activated the volumetric options. I've set the height of the volumetric light so that it goes into about the middle of the room, my intention being that when i render the scene the only volumetric light will be that which is getting in through the window hole, the rest should be blocked by the surrounding wall.

However, on rendering I'm getting volumetric light in the room for the entire shape of the (spot)light's cone, not just through the window. As if its just passing straight through the wall. I've also tried this with a distant light, and the same thing seems to be happening.

Any idea why this is happening? Surely it should only come through the window?
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Old 13-04-2004, 03:11 AM   #2
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Default heres a pic

Heres a picture to better illustrate the prob....
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File Type: jpg volprob.jpg (49.9 KB, 59 views)
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Old 13-04-2004, 10:58 AM   #3
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Be sure to switch on shadow casting for the light or else it will simply pass straight through your objects (This may actually need to be ray traced shadows too rather than shadow maps - can't remember, sorry).
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Old 13-04-2004, 12:14 PM   #4
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its on but i'm still getting the same results, i can't figure it out Any ideas?
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Old 13-04-2004, 12:22 PM   #5
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do you have ray traced shadows turned on in the render options tab
and on the light type make sure the shadow type is ray trace

Last edited by sspikedudley; 13-04-2004 at 12:25 PM.
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Old 13-04-2004, 09:26 PM   #6
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ok, i've made sure that i had all those settings that were recommended, i'm now getting the following very strange effect... the light IS now coming through the hole as it is supposed to, however where the light should be hitting the back of the wall, its now still showing right through the wall in black. I have absolutely no idea why this is happening. I've posted the scene file and object in the following post for y'all to have a look at to see if anyone can solve this.

Note: If i set the color of the object to black, then you can't see the black sections coming through, but for the purposes of the scene i'm working on, i don't want this surface to be just black.
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Old 13-04-2004, 09:29 PM   #7
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And heres the scene file and object.....
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File Type: zip volumetric_prob.zip (2.5 KB, 4 views)

Last edited by Fade; 14-04-2004 at 04:23 PM.
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Old 13-04-2004, 11:12 PM   #8
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Fade.. Go into your Volumetric options and try these settings. It maybe what your looking for.

Greg
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File Type: jpg volumetric_01.jpg (51.4 KB, 42 views)
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Old 14-04-2004, 11:02 AM   #9
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all you need to do to get rid of the black outline is turn your opacity down to 0 for a and then lower your luminosity setting or lower the density for a softer light
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Old 14-04-2004, 04:15 PM   #10
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Sir_Pro_View, sspikedudley, Thanks a lot! I finally got it sorted.
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Old 14-04-2004, 05:08 PM   #11
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oh, and you too Mark, sorry
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