Interior Animation Workflow and Questions

[kwok3d]

We are experiencing long rendering times in our 15-30 sec interior animation. So we were wondering if there is something we can change in our workflow to speed up the render times and maintain a similar quality level. I have included an image of the scene to help, please let me know if you need any further clarification. Thanks.

Current Workflow

1.Final output: LWF, 864x486, 30fps, 16-bit Tiff > CC > DVD
2.AA: AdaptiveSub, Mitchell or Area depending on scene
3.AA: -1,2 or 0,3
4.AA: Clr thresh 0.05
5.rQMC Nosie: 0.005
6.rQMC Global: 1.0
7.IR Map + LC, Load saved map > Render on BB
8.IR Map: Multiframe Incremental (every 30th)
Med-Animation, HSph=20 or 30, Interp=20.
Sample lookup: Density-based
9.LC: Fly-through, Scale=Screen, SubD=2000
SampleSize=0.03, Store with Direct Light
Pre-filter off, Filer=Nearest10, Use LC glossy-ray Checked
10.>>> RENDER IRMAP <<<
11.Load up the IR Map and turn off LC, send to BB.
12.>>> RENDER FINAL IMAGE <<<

Questions

Irradiance Map as 1st bounce
1.The frame seems to render a lot faster if we load up a saved IR map that was rendered with Reflect/Refractive in the global switches UNCHECKED. Is this ok to do?

Light cache as 2nd bounce
1.If we stick with Screen, and still getting noisy surface, should we keep raising the LC SubD?
2.If we switch to World Scale, how to we determine the sample size value?
3.LC seems to be burned on the IR Map that was saved out, so is it not necessary to save out the LC separately?
4.Since the LC seems to be burned onto the IR Map, is it ok to turn second bounce off for the final rendering? Or should we leave it on?

Lights
1.Should all lights be set to Store with IR map?
2.Should we use instance lights as much as possible?
3.When should we use No Decay?

Materials
1.Currently we don’t use interpolation. Should we stay away from using it?
2.If we don’t use interpolation, our materials require much higher subdivs when reflection glossiness is set to anything lower then 1.0. How high is too high for subdivs?
3.Should we set the material BRDF to Ward to exaggerate a lower reflection glossiness setting?

[DaForce]

Re: Interior Animation Workflow and Questions

Questions

Irradiance Map as 1st bounce
1.The frame seems to render a lot faster if we load up a saved IR map that was rendered with Reflect/Refractive in the global switches UNCHECKED. Is this ok to do?
In some cases yes. By default reflective is unticked anyway, unticked refractive means that "affect shadows" will no longer work. So it might be quicker as some glass wasnt having any light go thru it.

Light cache as 2nd bounce
1.If we stick with Screen, and still getting noisy surface, should we keep raising the LC SubD?
For animations use WORLD (see the tut in the help files)
http://www.spot3d.com/vray/help/150R...ials_imap2.htm

2.If we switch to World Scale, how to we determine the sample size value?
Trial and error, once you have done it a couple of times it becomes seconds nature. Also see link above.

3.LC seems to be burned on the IR Map that was saved out, so is it not necessary to save out the LC separately?
One of the only reasons to save out the LC seperately is if you have use LC for glossys or what ever its called.. ticked. But if you dont then yeah all the LC info is stored in the IRmap

4.Since the LC seems to be burned onto the IR Map, is it ok to turn second bounce off for the final rendering? Or should we leave it on?
Yes, but see the previous answer as well.

Lights
1.Should all lights be set to Store with IR map?
Depends, Stored with Irmap will be quick, but less quality. Not stored they will be more accurate but slower.

2.Should we use instance lights as much as possible?
I would say yes, but have no real reason behind it.

3.When should we use No Decay?
If you wnat things to be accurate you would use decay always. But in saying that, if you use a direct light and it hits a surface fairly close, then decay wont do much. I would suggest always using it.

Materials
1.Currently we don’t use interpolation. Should we stay away from using it?
Interpolation is a trade off between speed and quality. With it on, it will be quick but not look as nice. Often interpolation can cause problems with animations.

2.If we don’t use interpolation, our materials require much higher subdivs when reflection glossiness is set to anything lower then 1.0. How high is too high for subdivs?
How long is a piece of string, it depends on your AA and rQMC settings as well, so its hard to give a straight answer 8-20 should generally be enough. Test region renders will let you know what suits.

3.Should we set the material BRDF to Ward to exaggerate a lower reflection glossiness setting?
Again depends on other settings, and also material type..wood..metal..etc.

I hope that can help you without being too full of rubbish hehe

[kwok3d]

Thanks for the response. Thats what I thought for a lot of the answers but I wasn't sure. Its nice to have others to help you when you aren't sure.

Its just seems strange that the render times jumped up so much. We went from 15 min at the beginning to 4 hours towards the end. Thats what made me think there might be some problems with our workflow...

I completely forgot that they use world for LC in the tutorial.... duh
I will give it a try and see if that helps. Also we do have use LC for glossy rays ticked, so loading the LC at rendertime might help speed up some of the glossy calculations.

Thanks

[DaForce]

No problem, you will notice at the bottom of the first page of that tut, that it mentions the LC with glossy rays as well.
I think that may well help the speed.

That time increase is very odd. See how you go with the LC. Fingers crossed that it sorts it out for you.

What part of HK are you in BTW?

[gilpo]

Since you weren't specific as to where your time increase was, here are a few suggestions as we've recently had similar problems. If you've already answered one of these and I didn't see it, I apologize.

1. Make sure no object (especially the floor or walls) got cloned on top of themselves. This happened once to us and because we had the secondary ray bias increased, we didn't see the problem anywhere but the render times.

2. Is the time increase seen when rendering the frame from a saved irradiance map versus just rendering a single frame with a new irradiance map and LC? If so, your IrMap could be corrupt and a redo will fix.

3. If your LC is taking longer, make sure you don't have it set to show the LC while it calc's it. This sends render times through the roof for large scenes.

4. We always used Adaptive QMC for sampling. Never had much luck getting render times under control with Adaptive Sub.

5. Are you using static or dynamic memory? If you are using static, I just read somewhere in the forum that proxies still use the dynamic memory amount, so try setting it higher (if you are using proxies). If your using dynamic, also try increasing it.

6. Are you using any photometric lights or lights with IES webs? These increase times. Try using vray lights instead.

What are your render system specs? I've never had render times go that high on a render that size and your scene contents and settings are pretty close to what we always do. I don't think I've even broken 30min/frame. There sounds like a problem somewhere. Might try merging everything into a new file - this has been known to fix some things.

Something I've had to do was just start hiding objects until the times improved and that tells me where the problem is. Also try rendering with a plain gray material to see if it's texture/material related.

Good luck.

[DaForce]

Just to go into finer detail on Gilpo's point 5.
Proxies are always dynamic. So increasing the dynamic memory limit wether you are using static or dynamic memory might help.

But ideally you should only use proxies and dynamic memory as a last resort as your render will be slower BUT it will use less memory.

[percydaman]

Just to clarify something you said Daforce, I believe the OP is referring to the reflection/refraction override in the globals tab, not the GI tab. So if he creates an irrad map with those unchecked, yes he will have a smaller irrad map, and hence faster render times per se, but if he has like a wall mirror, whatever is reflected in the wall mirror wont have received any gi samples and will have issues. I know this from experience

[kwok3d]

We are using static memory for this scene.

There are some IES lights but they were in the part that rendered fast. Farther down the hallway there aren't any IES lights and thats when render times are jumping.

I will take a look at the geometry to see if there are multiple objects/faces. Most of it is from CAD so they might not have been modeled correctly...

As far as the image sampler goes, we have used both QMC and subdivision in the past. Usually our scenes don t have a lot of what i would call fine detail so we usually go with adaptive subdivision, but i will give it a try on QMC and see if that helps.

Personally I am hoping it is due to bad geometry so we can fix it quickly. These settings are pretty typical for us and we have never had a problem like this before... *fingers crossed*

[vlado]

If the scene is not heavy on RAM, you can try to increase the ray caster settings: set the "Max. level" to 100 and the "Face/level coeff" to 1.0 - it might make things somewhat faster.

Best regards,
Vlado

[DaForce]

Ahh yeah missed that rather important bit of information, was running on a handfull of sleep at that point (as I also am now) and must have glazed over it.
Thanks muchly for clarifying

[RErender]

Your getting sleepy, sleepy, sleeeeepy...

[DaForce]

dont need that. could fall asleep right here on the keyboard at work.
Didnt sleep at all last night.
And it wasnt because I was playing Supreme Commander all night long with 3 other mates.
.. it wasnt.. really.

[percydaman]

i recently saw some cool screenshots of that game. Is it pretty good?

[DaForce]

Yeah its really cool. Its a very good RTS. Prepare to loose alot of hours to it.
Had a 3 hour game last night (amongst others) and ended up playing thru the night.

Lots of depth to it, im still learning all the finer details of it.
II would highly recommend it if you like those sort of games.
Its the sequel to Total Annihilation.

[m_hinks]

I came across this post last week, and it know appears that it will be very useful in my next animation. However, without going over old ground, I would like to ask some more questions on this subject.

I have been rendering out very large stills from an interior scene, a tube station, and have been using IR (High preset base but with Hsph 120, interp samples 40, -4, -1 passes) and Light cache (650, size 0.04 screen, interp samples 20). The render times are high but the results are spot on.

However, I am now charged with the task of producing a 3 minute animation, a single cam walkthrough of the station from above ground, through the station, and in to the platform. The cams pretty much set up and Ive been doing some test render over the weekend. I have a lot of glossys and 60+ lights. Ive been trying with AA fixed 2, and seems to get not bad results but 3 would be best. I've not yet compared with adaptive and DMC for quality and render time.

My main concern is with the lighting. I realise I need to change from screen to world for LC, but the workflow to pre calc the LC and IR for a single cam 3 minute path is my problem!

Could someone explain the correct method. I am assuming I need to maybe work out the LC first on walkthought mode, with a load of samples, then save it, and use to the pre calc the IR, every 25th frameish?

However after reading this thread, should I be setting the LC as is, and just pre calc the IR, then load the IR and turn off the secondary?

Id be very gratfull for help in this.

Cheers