I've made an animated scene with 2,000 frames, which rendered fine but then I worked a bit harder on later frames and for some reason it now has shadow artefacts when rendering later frames! Help, any ideas please?! Stills look fine but animated you can see the shadows strobing inconsistently (see gif below).

via GIPHY

Link is here if that gif doesn't work

Lighting is consistent (not animated), what would cause these artefacts to appear? Can't understand it. I'm using Poser Pro 2012.

This should just be a simple pan past little yellow house models, so strobing shadows shouldn't happen. I haven't changed subsurface or IBL or shading rate or anything, can't figure out what would cause these shadow issues.

The only thing I changed between when the pans rendered fine and now, is I added 3D figures (about 3 full cartoon figures, animated poses), and a few props but nothing major. There's about 10 characters and 200 props in the scene, but that isn't unusual. I've cleared shadow maps, restarted the laptop (I know that's irrelevant but you know...), everything

Shadow maps? Ah, you're using depth mapped shadows? That's most likely your problem.

Did you render with IDL enabled? These look like IDL artefacts between frames.

If you are using IDL as Tony alludes to, then this is from the manual and may explain why your shadows are jittering:

Animation Considerations: When rendering out an animation while using IDL, make sure that multi-threaded rendering is not being used (set Number of Threads to 1 in the Render tab of the General Preferences dialog). If you leave the setting at 2 or higher, your renders will come out jittery, as the shadows and lighting will not line up from frame to frame.

Thanks so much for the help everyone.

This is PP2012 so there's no IDL options, but your hint did lead me towards the IBL light which I've turned off, another light had depth map shadows, and between those two changes it does seem to be fixed. Was excited by the 'threads' suggestion too, but that had no effect in this case. It must be a change I made in the scene which triggered it, because the first thousand frames rendered with zero artefacts.

Thanks again, nightmare having that kind of thing happen near the deadline for a video project! I need to get my work to buy the latest PP really, perhaps if this video goes well, they will :)

I say fixed it. It hasn't, but the artefacts are now faint enough that I think I can hide them with brightness/contrast in post, so I'm going to do that as I don't have time to start again with this scene.

This is PoserPro2012, the highlighted bit in the render settings is for IDL - InDirect Lighting.

Small nitpick - the D stands for Diffuse

Raven - no way, I'd never spotted that before! Haha funny what your eyes don't see :)

However, despite you being exactly right, in this case that box wasn't ticked anyway, so I can't turn it off. Here's my current sort-of-works equivalent (ie. mostly default):

No probs BB, happy to be corrected. Although this quote from the PP2012 manual is the reason I said it the way I did :)

Light Emitting Objects: We changed the face of rendering in Poser when we introduced Indirect Lighting (IDL).

dt00swc - he he, eyes do have a way of playing tricks on us :)