I've gotten back into animating in Poser after a long hiatus, and recently noticed the dreaded "Shadow Spazz" (aka dancing, modulating, or noisy shadows) in an animation I created.  I've done quite a few animations lately and had not had the problem.  I use raytraced (softened raytraced) shadows for this reason, as in the past shadow maps would always cause this and ray-tracing elimated it.

I tracked the culprit down to Indirect Lighting. It effects both shadows on objects and the ground.  *(Although I have animations with IDL on and similar light set-ups and no Shadow Spazz.)  *When I turn IDL off and render out the animation, all is well.  

Is this simply a case of needing to crank up the IDL quality in the render settings?  Or do certain light types and IDL cause this issue?  Any insight someone can provide would be greatly appreciated.

Thanks,
Tim

PS> Things I've eliminated:  

• Thought maybe network rendering and IDL didn't mix (thought I read that somewhere), but that was not the isue.

• Tried both  AVI and Image Sequence ... doesn't matter.  (both in uncompressed formats, LAGS and PNG (and TIF) respectively.

IDL only produces occlusion shadows.  problems may be associated with directional lites.  post lite settings so that the experts might advise.

I came across this in the manual (and this is what I was thinking of when I mentioned the Network Rendering and IDL):  

**"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."
 **

That seems ridiculous that you would have to cripple your render speed just to render IDL.  I'm going to render a short section with a single thread/cpu to see what happens.  I'm having a hard time believing this is it, although the description does seem to jive.  If that IS it, looks like I'll be going back to doing most of my renders in Vue.

If that isn't it (which I'm hoping) I'll post back with that info.  Thanks!

Using one thread actually made it  look much worse!  (Weird.)  I am relieved actually, as using one thread instead of 8 sounded horrible.

I now have IDL at 64, and** Irradiance turned down to 10** which seemed to help quite a bit.  But there is still some noise when light from a light-emitting object is cast into a shadowed area.  Maybe I need to crank up my render samples to 8 (from 4)?  I'll give it a shot. 

In the meantime, here are my light settings:

IBL LIGHT : SHADOWS OFF, Ambient OCC ON (Strength = 0.7)

LIGHT 2 (SPOT) : SHADOWS ON (RAY TRACED) Blur Radius 3.0 (down from 5.0 earlier) Samples 20 (I think higher samples made it worse IIRC). Shad. Min Bias (0.8), Ambiamt OCC ON (0.7)

LIGHT 3 (INF.) : SHADOWS ON (RAY TRACED), rest same as LIGHT 2

Thanks,

Tim

Why do you have AO on all your lights? And if you're using IDL, AO should be off completely. Use one or the other, but not both.

Laurie

And why IBL when using IDL.  Although both can be used, careful tweaking should be considered.  AO is most beneficial on IBL, not all lights, as Laurie points out.  However, IDL does shut down light based AO, but evaluates it in materials when clicked on in the Mat Room.

i had an animation where the lighting was nuts like you describe, messed with it for nearly a day and discovered that i had a light i hadnt set to non animating and had moved it a few times while setting up the scene and had forgotten about it...lol

:O)

yes, make sure all directional lites are set to ray-trace, non-animating in frame 1, before doing anything else.   but it may still get shadow jitter.

Wow, thanks for all of the replies everyone!  I REALLY appreciate the input, and had a feeling I'd be embarrassing myself with my lack of lighting knowledge.  But I'm enjoying the crash course.

Ok, it's defintely not animating lights ... that is the first thing I do when I start an animation.  (In fact, my default scene for loading Poser has the lights locked down.)  

My tweaks in the render engine have gotten me a lot closer to noiseless shadows, and have improved the IDL areas (like internal parts of this object where object-based lights are casting strong IDL) but the shadow spazz remains.  

Thanks for the info on AO lights and IDL Laurie,  I think that could very well be the culprit.  That makes sense now that I think about it, because the areas with the most problems are the areas with most AO.

And thanks Hborre for the tip on IDL/IBL and the further explanation regarding the various interactions.  In both cases, I like the look offered by IBL but also needed the IDL for object-based lighting and glows, etc.  Same for with AO ... it is appropriate for for other objects where IDL is not really a factor.  

Sounds like I need to do seperate render passes for these occasions and then composite.  I do a LOT of that anyway, so not a huge deal.  I just need to update my Python stuff for PP2012 and/or just use Vue.

Thanks!

-Tim

IDL with Irradiance Caching (IC) is a stochastic approximation. (Look up stochastic if it's not familiar. Without that word I'd have to say a hundred things.)

The more you rely on IC (for speed) the more error you should expect in the lighting. Since the error is stochastic, it's not the same error from one render to another.

Therefore, even if you're doing a still image, two renders in a row will not be the same.

IDL + IC contains artifacts, by definition. These artifacts will move in random ways, even if you change nothing.

It is possible to implement deterministic pseudo-randomness (repeatable, but still unpredictable), which would still have errors but they would not move around. I don't know why Poser is not implemented this way.

If you don't want stochastic approximation artifacts, set IC = 100. Prepare for very long renders.

IBL+AO is also stochastic.

Also, sometimes there is a reason that some renderers cost $8000.

Quote - Also, sometimes there is a reason that some renderers cost $8000.

LOL!  RIGHT!  Although, Vue, while not cheap, certainly handles things quite well as of late.  

Quote - IDL with Irradiance Caching (IC) is a stochastic approximation. (Look up stochastic if it's not familiar. Without that word I'd have to say a hundred things.)

Yes, I'm familiar with stochastic, and actually now that you mention it, I recall reading about this functionality of Poser, although I don't believe stochastic was ever used.  But basically it equates to randomness, and this explains a LOT why they don't recommend multiple processors with IDL (as each thread is getting a different result) and also why -- I would think for the EXACT same reason -- network rendering would not be recommended.

But from what you're saying, and from what I have observed, it sounds like (at least in Poser) IDL and Animation do not mix.  As even one still to another will be different, thus making it nearly impossible for any animation not to exude some type of "artifacting", correct?

Now, you mentioned cranking IC up to 100, but in my tests (and according to the Poser manual) the opposite is true ... lowering the IC (and to me, thus the depency on it as you mentioned) produced better results.  Still not great, but much better.  

It really seems like you can get fairly stable results using IDL with the right tweaks in the Firefly render engine, just as long as you don't have shadows interacting with it.   So ... it seems to me the logical thing to do would be to render a seperate shadow pass (without IDL) and then composite them together.  What do you think?

Thanks, Bill!

-Tim

The IC value represents the desired accuracy, which is inverse to how much the cache is used. When IC=100, you're saying you want 100% accuracy, which means 0% use of cached values. Lower values use the cache more, accepting less accuracy in exchange for greater speed.

When you lower the IC value, you're accepting huge inaccuracies, which predominantly express themselves as missing shadows in a lot of places. Which is another way to avoid shadows, right? So in a sense a very low IC does improve consistency, because it consistently fails to react to occlusion. This does not contradict anything I said, but does provide an alternative explanation to why you thought your results contradict what I said.

Basically you turn turn off small-scale occlusion when IC is set very low. If you elide all but the biggest and most obvious shadows, then yes it is very consistent. However, highly inaccurate.

Got it ... I think.  ;-)  Seriously, that makes sense ... particularly in this case where you have shadows, AO, and IDL all coalescing.  Yes, in sense, that is "avoiding" the shadows, lol.

Now "elide" ... there is a term I've not heard (or not often enough) before. ;-)  I imagine what I will do (although this is all somewhat theoretical until I can do some more tests) is use a normal IC setting (better accuracy) on a non-AO and/or non-IDL pass.  

I'll let you know what I find.

Thanks again!

All the best,
Tim

Hi again:

I did some further experiementing and can say with confidence that Bill was right on the money.  In summary, it appears to have everything to do with IDL and shadows, and seemed to be unaffected in any way by AO combo'd with IBL, multiple AO lights, etc.  Shadows remained smooth with IDL OFF but everything else as it was, actually.

That is unfortunate, because it would seem it is impossible to get non-spazzing shadows and have glow effects at the same time.  I suspect, and correct me if I'm wrong, that doing this in Vue using Luminous materials and GR will produce the same problem, right?  I mean **IDL **Poser is similar to GR in Vue, and I would think it would have the same issues with shadows, unless it (hopefully) handles it in a different way.

I don't suppose using hi-res shadow maps would avoid this problem, would it?  As I said, in my experience, dancing shadows were the defualt behaviour of mapped shadows, and is why I have been using ray-traced for some time in animation.

Thanks for any further help.  I'll be doing some renders in Vue in the meantime to see what can be achieved there.  Just not looking forward to setting up all my materials properly.  

Best,
Tim

I was right about Vue ... it does not like glowing objects and shadows either when using GR.  It did a MUCH better job than Poser, and the distortions are -- oddly enough -- happening on a wall far behind the object with the glowing materials.  They (the glowing materials) are not casting shadows on the wall either.

I'm not sure if a boost to GR quality would fix it or not, but for now I think I'll just do seperate render passes, unless someone has some ideas.  Maybe a post to the Vue forum is in order at this point, as I can pretty much conclude that Poser just is not capable of rendering not-spazz shadows.

-Tim

I've rendered animation with IDL set to 1 thread and my usual 8...and no matter what adjustments you make, the shadows will jitter.  My advice is to turn off IDL entirely and just make yourself a set of lights that have shadows set low and some off completely and do your best to simulate the IDL effects.  Otherwise it's jitter city.

You do realize this thread is a year old.

Quote - You do realize this thread is a year old.

Who cares? So what's your point?  I don't care if the thread is 5 years old (or 10) ... useful input is useful input.   He was providing useful information to a question I had asked ... so again, who cares how old the post is.  

I can't stand "Post-Nazi's" like you who make these imature posts about how old a post is ... it's a trend I see happening on lots of boards, but I didn't think I'd see it here.  Seems to come from the "I'm too cool for the Internet" generation.

Quote - I've rendered animation with IDL set to 1 thread and my usual 8...and no matter what adjustments you make, the shadows will jitter.  My advice is to turn off IDL entirely and just make yourself a set of lights that have shadows set low and some off completely and do your best to simulate the IDL effects.  Otherwise it's jitter city.

Thanks for the info/confirmation, JAG.  Yeah, or just try to avoid rendering in Poser (animation anyway) unless aboslutely necessary.  Or definitely not anything with IDL and animation.  I managed to get it around it rendering in Vue.  I just did a separate pass for the areas where flickering was caused with the IDL lights off.

what about exporting to luxrender for animation rendering?

Actually, I was just inquiring about that not too long ago.  It is certainly possible ... especially facilitated with the plugin available at RDNA's site (the name escapes me at the moment).  However, while it makes it less complicated, it would still be a major undertaking.  I definitely would consider it for any of my professional work that required hyper-realism and some element that required Poser.

     It may be quicker to render the animation out twice (or even thrice) and then compose the results as layers of even opacity weight, adjusting individual frames fo best results.  It's a crude workaround, but I've found it useful.

Yeah, that's pretty much what I did with the Vue renders.  The object with IBL/IDL looked mostly fine itself, oddly enough.  However, a wall waaaay in the background was producing flickering/spazzing shadows interestingly enough.  So I just rendered in two passes (got off easy on this one, eh?) and all was well.  There is some MINOR flicker on the object itself, but only noticeable because I am really looking for it.

     Vue has a rendering option specifically for reducing randomly-seeded IDL flicker in animations;  did you use that?

Hmmm ... in which version was this introduced?  I have had trouble keepimg up with all the amazing additions to that program.  I have 9.5 through the latest version.  Do you remember what it is called/where it is?

Thanks.

     Open the render options.  Click Advanced animation options, then look for flicker reduction.

Oh yeah, ok that one ... yeah, that's been around a LONG time ... I have version Infinite V5 as well, and I believe it was there way back then.  Unfortunately, I don't think that helps much.  I think I leave that on by default, but I could revisit the project and double-check and if it was off, see if that helps.  Maybe they have upgraded it in recent versions.

there's the Reality 3 at rdna.

there's also the pose2lux to atleast give it a try without investing.  Lux does caustics, iirc.