precalc'd or single frame IR map for animation?

[highpoly]

I know that in the tutorial "rendering a walk-through animation", the method was to use LC for both primary and secondary GI, calc it for whole animation and load it. Then make IR the primary, calc for the whole scene at every Nth frame, load it, and then render. This was just moving camera only.

Would this method work for a scene with moving objects as well? can you not use IR map when doing animations of moving objects? I know a lot of people say you have to use QMC for animations of moving object.

What would be the difference (aside from speed) using a multiframe pre-rendered and loaded IR map as opposed to single frame, in terms of flickering? I guess I am trying to find a way to use IR for animations since its so much smoother result in large flat areas. If not, brute force it is...

thoughts?

[vlado]

You cannot use a pre-saved irradiance map for moving objects due to the fact that the samples in a pre-saved map are fixed in time and space, rather than following the objects.

One possible way to handle the situation is to use the method described in this tutorial:

http://www.spot3d.com/vray/help/150R...rials_anim.htm

Best regards,
Vlado

[Yohan]

I dont think that a pre-rendered IR-map will work when working with moving objects.

I always use pre-rendered LC and IR map when working with ie flythroughs with no moving objects and it gives a great an non-flickering result.

I would probarbly render the moving object in a seperate render and put it together when both renders are complete.

[highpoly]

I see..that makes sense. I know the method in that tutorial is the preferred one.

But would the same hold true for 'single frame' at rendertime (ie non calc'd) IR map? Reason I ask is trying to understand limitations of IR map better.

For arguments sake, assuming there was no way to do comping later, would a single frame IR map setting still not work or have to use direct/brute force computation instead to get the moving object and the scene in one shot?

sorry for beating a dead GI horse...

[Clifton Santiago]

If its a single frame, there is no movement so it doesn't matter. For moving objects try QMC/QMC or QMC/LC

[highpoly]

thanks bro...

bit unclear language on my part, I meant single frame in the IR mode (single frame, incremental, etc..) with an animation..not single frame of rendering.

I guess QMC in the first bounce would be the safest (and slowest and potentially noisiest, but flicker-free) for animations eh?

I will try that...

[RErender]

with DE and high enough irmap settings it should work, haven't tested it though

[highpoly]

thanks...I am gonna do some tests with all the settings mentioned and that tutorial Vlado mentioned..

[Neilg]

IR map tends to look awful on single frame, even with fairly high settings. Its pretty blotchy, you just dont notice when you have nothing to compare it directly to.

QMC/LC works well for moving objects though.

[highpoly]

I did this scene as a simple test for the kind of rendering I'm talking about. In this scene, there really is no enviroment per se (just a vray plane) so rendering in passes to separtate background and animated objects wouldnt help that much in this case I think...

in this test, its just a greebled box, vray plane, and vray light with some environment light contributing. I think since its open environment, 2nd bounce isnt contributing much?

I tried both with IR/QMC and QMC/LC. Needless to say the QMC came out better but took like 6 times longer to render. Did I overdo the settings on the QMC? here are the settings for both setups. I can post the max file if anyone is interested. Is there a happy medium between these 2 settings/results?

IR/QMC
------------------------------
quicktime below
http://www.geocities.com/highpoly/BLOG/ir-test4.rar

Vray light: 16 subs, Store in IR=off
Adapt Sub AA = 0/3, normal checked on
Enrvir= 0.5 mult
IR map= high (animation), 50 Hsph, 20 inter samples
rQMC= 0.85, 0.002, 8, 2.0
time: 50 min at 320 x 240


QMC/LC
----------------------------------
quicktime below
http://www.geocities.com/highpoly/BLOG/test4.rar

Vray light: 16 subs, Store in IR=off
Adapt Sub AA = 0/3, normal checked on , AA filter = OFF
Enrvir= 0.5 mult
LC = 1000, 0.02, screen, store direct = on, filter:nearest. samples=10
rQMC= 0.85, 0.002, 8, 16.0 (so much grain so went high on this)
time: 5 hours at 320 x 240


And lastly here is a really stupid question, but...
If using IR map for primary, and STORE IN IR is OFF in lights plus its off in the Vray materials, is the IR map being used at all? or is that basically just direct comp?

thanks,
Marc

[ene.xis]

well...
i dunno why u woudn t use the lc in flythrough mode...
nevertheless if ur calc lc every frame then i d reduce drasticly the amounts of samples....they re wayyyyy too much for that scene!


still there might be some room for other settings adjustments!

[highpoly]

hmm...
i guess I thought you cant use a pre-calculated IR or LC map when dealing with animated objects..i thought it all had to be frame by frame..

I am finding that in order to get the IR map to look anywhere near the QMC, its taking similiar time so might as well just use QMC, but like you siad, pull back the samples..you mean the LC samples, not the rQMC global samples right?

sigh, i wish i were smarter so all this were easier!

[ene.xis]

yeah the lc samples i ment!

in fact i m not sure if flythrough mode would be correct to use in moving objects...
but if u reduce ur samples to 200-300 i think they re enough and ur render time will reduce drasticly id suppose!

[highpoly]

just wanted to say that tutorial for 'animation with moving objects' is amazing...answers a lot of questions...thanks to the writers!