Animation - Moving Objects

[jujubee]

I have a scene with moving objects. I've saved out a Lightcache and can render fast from that with the moving objects hidden.

My questions:

1) What is the best method to reinclude these moving objects within the scene using a different lighting method around these particular objects? I'd like to merge two different methods (ie lc/lc for the flythrough/speed and something else for the moving pieces that would approximate the lighting solution.)

2) I've read the walkthrough with moving objects on the spot3d help files. Vrayspherefade atmospheric is one possibility. However, using this would cause a sphere/radius incorporating a slightly different light solution. lc/lc for moving objects frame by frame causes an irregular edge to appear where the two portions are composited together. Plus lc/lc when it is not saved causes randomized samplings. You can't save a proper solution with moving objects without causing artifacts.

3) Is there a recommended/particular lighting method of rendering the moving objects/shadows that would work best in this situation? Anyone elses recommendations?

4) Is there a simpler way of compositing the two segments together other than using vrayspherefade? Ie. Alpha channels, mattes, objectID render elements? How could I simply go about this?

[Olli96]

What i did on my last project was to render out my camera with all animated objects hidden. then i created a copy of my scene, set all non-animated objects as a matte/shadow object (VRay Properties, alpha -1) and unhided my animated objects. then i rendered every frame of those animated objects and combinded them later in combustion, just make sure you save the alpha.
i never tried lc/lc for animation, but usually a irradiance map with the medium preset and qmc should work quite well for animated objects. it might be not the best workflow, but this way you can use any render engine for your animated objects.

[jujubee]

Thanks Olli. It's good to know - skip the frames which have motion involved. However unlike the vraysphere, you end up rendering the entire background/plate where the animation portion is involved. I guess you can average out the color and apply a blanket material to the rest of the scene if GI accuracy is not vital.

I'm beginning to wonder if the Vrayspherefade works with Object ID then one could simply key out the background with the sphere. Unfortunately, Vrayspherefade didn't work with Alpha channnels.

[joconnell]

Yeah I'm the same - cached irmap / lc for the environment and then qmc / lc for the animated objects with the environment objects set to matte -1.

[jujubee]

How are you guys compositing in the shadows?

[Clifton Santiago]

And also how are you compositing reflections of moving geometry

[mmikee]

I had to render a bedroom scene with an animated ceiling fan on my last
project. What I did was render the animation without the fan blades. Then
I used a per pixel camera map on all the geometry and unhid the blades.
Then I region rendered the fan blades using QMC/LC and comped it in post. The reason that I used the camera map was to be able to get the
reflections on the blades. And it rendered alot faster than a region render of the entire geometry. Of course, this was a very simple moving object.
Not sure if it would work for you.

Regards,
Mike