suggestions for optimal vray settings when animating?

[stayinwonderland]

I'm about to render a small scene and this will be my first decent animation render in vray (because it takes so long I haven't bothered before, but now it's serious porfolio polishing time).

 

Here is a sample (note: just a test render, the final will not be as noisey):

 

 

There's a lot of soft reflections which means high reflection subdivs and on the rest renders there's obviously flickering.

 

I just want my final render to be as smooth as possible but like I say, have never used vray for animation before so don't know the methods for nice clean frame-by-frame renders.

 

I saw someone say to use brute force? I'm currently using irradiance with light cache.

 

Trying to keep frames down to sub 10 minutes for 720 x 406 x 270 frames @ 30fps.

 

Thoughts??

[Q-Bix]

Im no expert on animation but i would always render the Irradiance map and Light Cache out first individually to files with "dont render final image" on.

 

Once you have a good lighting calc to use from file, its easier to optimse settings to get the effect you want with a minimum render time per frame.

 

I guess with that resulution you would want to get a render time less than a minute per frame?

[stayinwonderland]

hmm, that's interesting. I'd like a short render time obviously, but right now I have a minute per frame at smaller than 720x406 and the very lowest settings, so that isn't a fair expectation.

 

I don't suppose you could elaborate on the technique you mentioned at all? I'm not familiar with that process. Much appreciated

[Q-Bix]

This is the tutorial i followed.

 

Hope it helps.

 

http://www.spot3d.com/vray/help/150SP1/tutorials_imap2.htm

[Corey Beaulieu]

Soft reflections and short render times don't exactly walk hand-in-hand for a high quality image. I'm used to waiting in the 15-20min range for slightly bigger (1280x720). You can save some extra time by reducing your frame rate to 24fps (23.976 actually).

 

The pre-calc IRR method is good. Place your secondary to light cache and set it to "Fly-through." Then set your IRR to "Multi-frame incremental" and set a place for it to save. Tick "don't render final image in the global settings and render every nth frame (n = 5-10 on faster cams, 1 or 2 per second of footage for slow cams). Then on the final render setup put secondary to "None" and IRR to "From File" and load your saved IRR (with light cache mind you- it stores in the IRR). Un-tick "Don't render Final Image" and set N back to 1.

 

If you are willing to wait a bit extra for an even higher quality, set your DMC to 2/8 or even 4/16. You can set the color threshold in the DMC to 0.005 as well.

 

Lastly, get a BUNCH of passes. They're free with the render and you never which one is going to save your project from a re-render.

 

All of this assumes the camera moving and not the objects by the way... Brute force and a lot of patience is how you render moving objects.

[stayinwonderland]

Cool. I think much of what you said Corey, is covered in the previous link. Which I'm going through now. Looks a tad complicated! So I expect I may be back with follow up questions. Cheers for the pointers, seems most useful. I was just gonna render it like I do with stills!

[Corey Beaulieu]

Cool. I think much of what you said Corey, is covered in the previous link.

 

It is... I've been through that a while back. I thought I'd give you the cliff notes. The one difference, and I hear it a lot, is that many say that you need to render a light cahe, save it, then load it into the IRR, save it, and then load both at final render. Light Cache store with the IRR file so just do them together. I have never had an issue.

 

Feel free to keep this thread going or PM me if you'd like. Animation render is an awkward start, but it becomes old-hat after a few.

[Andres del Castillo]

Hi Andy, I agree with Daniel, that is the concept. Additionally, you can use this script , wich make the same with an automated process. For a thight pipeline, you can use it, and after that you can go deeper with theory.

The basic is that you must not calculate gi in all frames, because it produces flickering. You should do it en steps or group of frames, with incremental mode. After that, save gi map, and turn on "from file" and render the animation. Of course this is a very summarized version, you should read the tutorial that Daniel mentions. I hope that helps.

[stayinwonderland]

Ok, was about to start on that journey when I did a couple of still renders to get my reflection subdivs working.

 

Problem is, on low settings a render = a couple of mins, on medium settings a render = 5-6 mins but to get rid of the noise I need to use high subdivs (like 64) which takes a still render up to 25 mins.

 

So what do I do there? Just find a way to avoid soft reflections? I'm also guessing any noise left in would flicker like mad in an animation.

 

Just want to get a nice still frame before I set out to render a sequence.

[Corey Beaulieu]

You should be able to get this done with lower Sub-d's. Like 24-32 max. With a Raw Ref pass you can gaussian blur it 1.0 or less to smooth the noise.

 

or...

 

Technically speaking you should be able to reduce the number of calculated subdivisions with the DMC Sampler. Going fully adaptive and upping the Min/Max values should divide calculated divisions across all cast rays. Meaning that if you were to go from a default of 4 in the max to 32 with your 64 subdivisions, then each cast ray is going to sample 2 subdivisions instead of 16 with the default in order to return the same result. The one stipulation is that you are casting more rays in this scenario so your scene would really need to be full of highly subdivided materials and lights in order to trade the increase of rays for the a shorter render time overall. The real control here is the threshold that you use for noise and color.

 

I've done a bunch of tests, but never a full stresser and found that it's tough to find/meet the point that you will trade cast rays and time, but I am always very impressed with the result. Often it will take a few minutes longer (when the point is not met), but the result is much better.

 

This is a good read when you feel up to a heavy one: http://www.interstation3d.com/tutorials/vray_dmc_sampler/demistyfing_dmc.html

 

As far as noise go in your final animation, I would un-tick time independent. Static noise (When left Ticked) always makes animations look like there is a grain filter on them.

Edited August 14, 2012 by CoreyMBeaulieu
Clarity

[stayinwonderland]

Ok, thanks everyone for the tips. I've been going through all of them (although will save the heavy reading for another time - but read I will!).

 

Here's what I have so far:

 

 

I saved 30 seconds by turning off secondary GI. Is that about right? It was 8:37 using light cache as secondary but 7:52 with that set to 'none'.

 

Ref subdivs are 32.

 

For a similar (smoother, less noise) result I was seeing 25 minute frames and that was with no pre saved GI files. Like a normal still render setting.

 

So yeah, I think this animation method is pretty sweet. Still quite long though, would have liked to have seen it around the 3-4 minute mark. At that rate I could render an 8ish second animation in two nights' render.

 

8 x 216 (24fps) = 28 hours

 

Thoughts?

[Corey Beaulieu]

I think it looks good. The last thing you'll want to consider is the fact that one typically adds a bit of motion blur in post. That will smooth out and soften what ever lingers.

 

AS to a shot, I think your sky could be a bit brighter. Other than that, I can't wait to see your Magenta/Orange/Blue (ish) color pallete after your do some post. I think it's going to look really sweet.

[stayinwonderland]

Cheers I think I'll separate out the sky for post - providing the alpha separation is clean at such low res. I also have some rain falling on the lense which I did with a still practise shot before hand. Subtle though - not cheesy.

 

Motion blur won't work because the camera move is slow and smooth.

 

I'll try to remember to post the results here - although it will take a little while :/

[stayinwonderland]

Oh, one more question. My vray alpha render element is just coming out as noise - mainly just plain white with sparse black dots. Any ideas??

[Corey Beaulieu]

First off, I'd say render it with a background that is black anyway. You will experience far less pre-multiplied, alpha fringing that way. By this I mean, where your rendered sky and your replacement sky different in color will turn funny colors in post. If you want it for GI and Reflection, just use the environment overrides.

 

But, my only thoughts are 1) that something got corrupt with the first one you added, delete it and add a new one. 2) that you are using some sort of fog, which always screws up the alpha channel, and/or 3) that you may be rendering in 16-bit or better and saying it looks that way from a frame buffer view. I see this a lot with Multi-mattes and alpha's, but it always goes away in a legitimate image viewing program like PS or AE.

[stayinwonderland]

Hmm, you sure black would be the answer? I thought you try to best match whatever the sky would be? So in this case, medium grey?

 

Ok, so 1) I tried that and it didn't change 2) not using fog. 3) Ah, now it does say 16bit on the frame buffer and when I save it (jpeg) and open it in photoshop.... it's pure white :/

[Corey Beaulieu]

it's pure white :/

 

An alpha should be pure white, but will never alias correctly as a jpeg. Jpeg's are lossy. Save a 16-bit Tiff if you want and tick "store alpha." When you open that in PS you'll be able to ctrl+click the alpha channel and have a perfect selection.

 

The best match system would work in solving the potential problem I mentioned for sure, but image a scenario where you switch the sky choice after you render it...Black is just always the best bet for clean alpha channels.

[stayinwonderland]

Ok, I set the bg to black and the alpha works. Maybe it doesn't like HDR backgrounds and treats them like solids? I also tried a quick composite in photoshop and it works a treat - even with a much lighter sky.

 

Thanks for all your input. I'm not just about ready to hit render and go to bed!

[stayinwonderland]

Damn. Still having problems.

 

 

So this is how the alpha renders in max. When it's opened in say photoshop, it just looks black and white without the noise.. but... when you save the diffuse as a tga with alpha, the noise we see in the above image gets applied to it - and it looks really noisy.

 

Save it as a normal jpeg and it's fine but it seems these black dots are carrying through to the alpha when saved as 32 bit tgas.

 

EDIT: another issue... I have two lights that animate on in the scene. As I've precalculated the light, rather than being off at the start, there's still light coming off them from the cached files. Any advice?

Edited August 15, 2012 by stayinwonderland

[Corey Beaulieu]

So animated lights become animated objects, which is to say, not something that you can render with IRR/Light Cache. You have to Brute force them. Brute force is noisy and slow and I'd doubt it will meet your standards.

 

One way around this would be to render the lights off, no animation from 0 - the frame they finish animating on and the render a separate version with the light totally on from the frame the light starts to the end. This will give you proper GI and you can just fade between.

 

or...

 

You can render them entirely off. Then go back in and turn GI off and render the scene with a couple "Light Select" passes. Just place the lights in the element list and you should get a separate element for each light. "Add" these in post and animate the opacity coming on. This is not perfect GI, but since your base has it, it is really close. One thing about comping it though is talked about on this thread: http://forums.cgarchitect.com/70280-vray-light-select-element-workflows.html

 

Hope this helps.

[stayinwonderland]

Ok, I've been trying to find the answer to this to save bugging you but can't quite get the answer I'm looking for.

 

I've had some pretty good results using IRR (+ saved map) + brute force. But that's just a total guess as I don't know how to properly set up for brute force i.e. do I use it as both primary and secondary or just secondary and if so can i use IRR for primary and if so should I calculate it every frame etc.

[Corey Beaulieu]

I've never done an IRR+Brute Force Before...

 

A usual BF setup would be Brute Force Primary and Light Cache Secondary. You put Light Cache to single frame and render. No Pre-calc. Then you get yourself a hobby and start learning how knit or something because its going to be a while.

 

Brute force is all about Noise/Color Threshold as well as the Subdiv's. 24 is high-is, but good. Truthfully, the softness of Brute Force is realistic as can be, but we 3D guys always call it overly noisy.

[Nic H]

Yep looks like you have animated lights so you will need to do them separately and comp them over (which I recommend) or take the hit and use brute force / brute force or LC (slow and noisey)

 

Id pre calculate IRR/LC for the base image with ambient environment light then seperately do a brute force pass with only the animated lights and screen it over in post.

 

Also see you are rendering to 30fps and you live in the UK which is PAL (25fps)!

 

Make lots of elements - multimattes! zdepth! specular! lighting! reflection for starters. Allows for a lot of flexibility in post.

Sounds like this is going to be a somewhat steep learning curve but its worth trying and doing these things it will improve the quality of your work out of sight.

[stayinwonderland]

Ok guys, here's what I have after rendering overnight. I take on board your comments about seperate passes and wanted to just try this on for size.

 

http://www.stayinwonderland.com/images/sketchbook/3d/IRR+bruteForce.mov

 

This is just like 2-3 seconds and it's comped in AE.

 

I actually used IRR in primary (from file) and Brute in secondary. The BF alone was very noisy but when I turned on IRR too, it was fine and with not much difference in render time. Time for lights-out frames is sub 10 minutes and lights on is about 12-14.

 

BF subdivs are 8 (16 saw hardly any change) and DMC is 4/12 where less than 4 saw a fair bit of change in terms of noise. Noise threshold is set to 0.005.

 

What I'm gonna try next is to render IRR+LC for the until frames and see if that speeds things up.

 

Frame rate is actually 24. I'm not intending on showing this anywhere but vimeo really.

 

So, thoughts on quality/noise etc.?

[Corey Beaulieu]

I think that you have a nice and clean looking render there. It has a video softness that is realistic and the cleanliness of the lights is good.

 

I think that the first light comes on better. Maybe its in my mind, but there is a pop at the end of the animation of the second light that isn't there in the first.

 

The only other comments I would have are that I feel that the grey quality of the right side of the video should be a blue-is purple kind of color and that there should be a bit more contrast overall.

 

I like what you're getting though. It's looking good.