VRAYforC4D: GI animation tut-02

[STRAT]

FLICKER FREE OBJECT ANIMATION

 

In tut-01 of my previous gi tutorial thread we discussed and went through the procedures of gi camera animation; animated scenes where only the camera moves. http://www.cgarchitect.com/vb/33137-vrayforc4d-gi-animation-tut-01-a.html

 

In this thread we'll look at object animation with gi. In my testing i've used a scenario which includes a fair amount of motion - camera movement, moving and colour changing lighting, moving meshes (some colour changing) etc etc. I've also used an internal scene, as these generally need more setting up and render slower than external scenes in the whole.

Also, i have not included a test scene as the settings described below should be fairly adaptable to suit your own scenes.

 

It should also be pointed out that whatever method you choose to adopt, render times are considerably slower for object animation than that of camera animation due to the nature of high settings and samples that are needed to eliminate flicker. The settings below aren't an example of uber quality, but best quality with usable render speed. I'm lucky enough to have a couple of oct processing computers at my disposal and the use of a render farm. Without these facilities i doubt i'd be writing this thread now

Saying that, as you'll see, render times are very pleasing indeed, and it's most common for professional users/studios to budget in the cost of the use of a render farm into their work flow these days.

 

My results are based on an animation of 250 frames at 25 frames per second at a 16:9 resolution of 1024x756 pixels. I've also used standard AA settings (as you'll see). AA is most subjective, and is a major cause of slow rendering. A lot of my rendering is for DVD and TV so i use nominal settings, but even for my high res still work i like to use regular standards. They really do work i assure you

The scene also includes a couple of glossy materials, and 1 huge area light for the general internal lighting. (samps@25). Most unorthodox, but in our opinion is a great method for still and animated rendering.

(also, any flicker you see in the example movies is purely down to movie compression)

 

 

OPTION 1 - IRRADIANCE MAP AND LIGHT CACHE

 

http://www.leedavid.co.uk/steve/IRandLC.mp4

 

Render time - 9.5 hours to precache, + 2.5 hours for final render.

 

IR and LC is considered the most popular stills or camera anim method by many. It is a great method, but ironically it takes a fair bit of experimenting with the settings to get it flicker free. It's always a case of finding the lowest/fastest settings you can against quality of render.

 

1 ) Render the IR map off. Go up to the main OUTPUT tab and change the resolution to 2/3 the size of the final resolution (1/2 might be passable, and full res would obviously be best, but 2/3 works good) and click on ALL FRAMES, but dont save anything.

 

2 ) in the vray tab, click on DONT RENDER FINAL IMAGE.

 

3 ) switch off all AA, and leave the dmc sampler as it is.

 

4 ) in the gi tab, change prim bounces to irradiance and secondarys to light cache. The irradiance settings are: min/max= -3/-2, HS=200, IS=30, IF=1, IT=0.3, NT=0.2, DT=0.3, set mode to ANIM PREPASS, and check the AutoSave button on Render End. Save the maps as, for example, IRPASS_

 

5 ) the light cache settings should be SD=2000, P=8 (or the no. of processors you have). I also turned off any lc filters and pre-filters. mode is SINGLE FRAME

 

6 ) hit render. It'll then render every frame off for the IR, at two thirds size. This might take a fair bit of time, so if you want to lower any of the said settings then please to so, but you'll then be more and more open to flicker.

 

7 ) once rendered, change the OUTPUT resolution back up to full size, type on a name to save your image sequence and turn off DONT RENDER FINAL IMAGE.

 

8 ) Turn on AA, i use aDMC @ 1x8x0.01 with a DISC filter @ 0.75

 

9 ) Change the IR mode to ANIM RENDER, then copy the name of the first file below into the LOAD FILE box. Switch off AUTO SAVE. Leave LC as it is.

 

10 ) change the INTERPOLATED FRAMES to 4. In my examples, a higher value slowed down rendering and lessened the gi effect, and less gave more flicker.

 

11 ) hit render again. Your final animation should now render with (hopefully) no or minimum gi flicker.

 

 

 

OPTION 2 - IRRADIANCE MAP AND BRUTE FORCE

 

http://www.leedavid.co.uk/steve/IRandBF.mp4

 

Render time - 15 hours to precache, + 3 hours for final render.

 

IR and BF requires almost exactly the same method of scene set up, and gives most pleasing results.

 

1 ) Render the IR map off. Go up to the main OUTPUT tab and change the resolution to 2/3 the size of the final resolution (1/2 might be passable, and full res would obviously be best, but 2/3 works good) and click on ALL FRAMES, but dont save anything.

 

2 ) in the vray tab, click on DONT RENDER FINAL IMAGE.

 

3 ) switch off all AA, and leave the dmc sampler as it is.

 

4 ) in the gi tab, change prim bounces to irradiance and secondarys to brute force. The irradiance settings are: min/max= -3/-2, HS=200, IS=30, IF=1, IT=0.3, NT=0.2, DT=0.3, set mode to ANIM PREPASS, and check the AutoSave button on Render End. Save the maps as, for example, IRPASS_

 

5 ) the brute force settings are 6 and 3

 

6 ) hit render. It'll then render every frame off for the IR, at two thirds size. This might take a fair bit of time, so if you want to lower any of the said settings then please to so, but you'll then be more and more open to flicker.

 

7 ) once rendered, change the OUTPUT resolution back up to full size, type on a name to save your image sequence and turn off DONT RENDER FINAL IMAGE.

 

8 ) Turn on AA, i use aDMC @ 1x8x0.01 with a DISC filter @ 0.75

 

9 ) Change the IR mode to ANIM RENDER, then copy the name of the first file below into the LOAD FILE box. Switch off AUTO SAVE. Leave BF as it is.

 

10 ) change the INTERPOLATED FRAMES to 4. In my examples, a higher value slowed down rendering and lessened the gi effect, and less gave more flicker.

 

11 ) hit render again. Your final animation should now render with (hopefully) no or minimum gi flicker.

 

 

 

OPTION 3 - BRUTE FORCE AND LIGHT CACHE

 

http://www.leedavid.co.uk/steve/BFandLC.mp4

 

Render time - 2.5 hours complete for final render.

 

BF and LC is the prefered object animation mode if i had a choice. It renders smooth, clean, flicker free and very fast. The dmc controls together with altered AA give the grain a nice clean finish.

 

1 ) BF and LC is a 'live' or 'on the hoof' render method, so no pre-caching is needed. Go up to the main OUTPUT tab and change the resolution to the full final anim size. Also save the image sequence to your liking.

 

2 ) in the vray tab, leave DONT RENDER FINAL IMAGE unclicked

 

3 ) AA = aDMC 1x8x0.01 with PARZEN filter @ 1.5

 

4 ) DMC sampler: AM=0.9, NT=0.5, GSD=3, MS=8

 

5 ) in the GI tab, prims set to BF and seconds to LC. The BF settings are set to 14. LC is SD=2000, P=8 (or the no. of processors you have). I also turned off any lc filters and pre-filters. mode is SINGLE FRAME

 

6 ) hit render again. Your final animation should now render with (hopefully) no or minimum gi flicker.

 

 

 

OPTION 4 - BRUTE FORCE AND BRUTE FORCE

 

http://www.leedavid.co.uk/steve/BFandBF.mp4

 

Render time - 7 hours complete for final render.

 

BF and BF gives a very similar finish to the BF + LC option, only takes longer and needs more attention to settings.

 

1 ) BF and BF is a 'live' or 'on the hoof' render method, so no pre-caching is needed. Go up to the main OUTPUT tab and change the resolution to the full final anim size. Also save the image sequence to your liking.

 

2 ) in the vray tab, leave DONT RENDER FINAL IMAGE unclicked

 

3 ) AA = aDMC 1x8x0.01 with PARZEN filter @ 2

 

4 ) DMC sampler: AM=0.85, NT=0.5, GSD=1, MS=8

 

5 ) in the GI tab, prims set to BF and seconds to BF. The BF settings are set to 20 and 4.

 

6 ) hit render again. Your final animation should now render with (hopefully) no or minimum gi flicker.

 

 

These settings work nicely on my typical internal rendering, so hopefully should also work on yours. As can be seen, BF+LC is, imo, the nicest result, and it renders infinitely faster than the pre-cache methods of gi.

You'll also need to carefully play with your phys camera settings, saturation levels, contrasts, multipliers and colour mapping settings to get the correct visual outputs you're after. A single change of gi render method is not enough on it's own.

 

Anyway, i hope this tutorial will prove of help to you. It certainly tough me a lot and gave me a proper understanding of where i'm going. If i've made any step errors or missed out any points then please inform me and i'll correct it. Thanks especially to Stefan Laub (one of the creators) for a number of helpful direction pushes, and to Dann Stubbs and his RenderKing render farm