View Full Version : Instance soft shadows & motion blur

04-16-2012, 04:34 PM
Hey all,

Running into a show stopper issue with Native instancing in LW11 build 2238.

It seems the only way to get instanced geometry to have motion blur is by setting the motion blur passes (using perspec. camera). It's an easy work-around but in previous versions you could have 10 AA on a shot with 1 pass of photo real MB and still get decent motion blur. Now with instancing, regardless of your min / max samples, you have to have high motion blur passes for it to look decent. The interesting thing here is that regardless of how many MB passes you set your scene to, MB on the instanced geometry doesn't get picked up in any of the render buffers.

I'm currently trying to render out an RGB pass and a separate shadow pass. The shadows for the geometry look semi-correct (not as soft as the shadows really are in the RGB render), but the shadows for the instanced geometry are hard, as if it came from a distant light. We're using 2 dome lights with about 45 degress and the other at 90.

I've tried a workaround of having a shadow catch object with it's alpha set to shadow density. This produces the same result as the shadow pass from the buffer export.

The image below shows the RGB render on the left with nice soft shadows. The right side of the image shows the same spot while looking at the shadow output of the compositing buffer export. The difference becomes pretty obvious.


Apologies for the small image, it's all I can show and I don't have time to set up a different scene.

Has anyone else run into these issues? I love a lot of the native instancing but there's definitely a lot of issues.