View Full Version : Volumetric light issue

06-22-2017, 01:39 PM
I'm baffled by this. I get a very dark to light area where my volumetric distant light height stops during an F9 render. :screwy: Looks fine in VPR. What is going on? Any assistance would be much appreciated.


06-22-2017, 02:50 PM
render panel, raytrace transparency perhaps.

you also got affect diffuse and specular off, that may not be it though.

06-22-2017, 03:14 PM
On a second thought...that may not be the issue, and I recall having the same issues myself when doing some volumetric light shafts on exterior rocks, but I canīrecall what it was was really...I solved though, something in the render panel or the global illumination, not sure about ray recursion.

06-22-2017, 03:40 PM
directional rays may be something to look in to in global illumination, that can yield completly different shading and rendering between vpr and final render, activate it to match, or uncheck it and it may differ but it becomes faster to render.

06-22-2017, 05:49 PM
If you don't render with passes you can do the final render with vpr.
Be sure you don't have the draft mode active for vpr.

06-22-2017, 10:15 PM
Figured it out! Apparently the cone or disc that defines the shape and size of the volumetric area is an "object" and therefore is calculated in the use of any ambient occlusion node on your materials. As far as I can tell there is no falloff either so its a very abrupt darkening. Doesn't matter which ambient occlusion node is used. This has to be a bug?

06-23-2017, 02:59 PM
Yes, easy to reproduce and your description seems to be the case. It has the same effect on the Occlusion nodes when the Light type is set to Point with a Volumetric sphere. I certainly don't think it's correct behavior, so I'd call it a bug.