Tutorial: Simulating Self-Illumination Materials

[jpl1040]

Here's another tutorial we created to help understand the best ways to use Self-Illumination in VRay 1.5 final:

http://www.trinity3d.com/tutorials/v...ls/index.shtml

[Rhys]

Thanks thats really useful, When you use light cache over qmc as secondary bounce do you pre calculate this with every nth frame being around 3 ?

[jpl1040]

Precalculating Light Cache

If I need to precalculate my light cache, I will set nth frame to 1 and set it to render a single frame. (as opposed to "active time segment" or "range") Then I go to time configuration and set the start and end to the duration of the segment i want to precalculate.

Go to your indirect illumination tab and select the light cache parameters. Change the mode to "flythrough" and set it to auto-save somewhere on your harddrive. Then go to the v-ray tab and check "don't render final image" since you don't need the rendered frame, just the light cache.

When you click render, you will see a smear-looking image if you have "show calc. phase" checked. That's your lightcache.

^^^ FROM MATT TYREE FOR JIM LAMMERS AT TRINITY ANIMATION

[Rhys]

does that work with moving objects thought, dont you get a strange trail of color where the shape moves ?

for scene with not moving obecjts i usually set the active time segment say 1-300 then set dont render final image, put both primary and second boucnes to light cache, set about 3000 light cache samples on screen 0,01 and then set auto save.

but with moving objects i thought you had to choose a nth frame.

[jpl1040]

LC precalc

Are you using only lightcache for your render or are you switching your primary back to IRmap after you precompute the lightcache?

I don't use nth frame for the light cache because when you set it to flythrough, it samples every frame in your time configuration frame range, even though you have set it to single frame. And its really fast so you can afford to do it without skipping frames.

I always set my primary and secondary to light cache when i'm precalculating a light cache, but I switch primary to IRmap afterwords. You can precalc your irmap while using the already precalculated lightcache.

I've never had any strange trails of color for moving objects. As long as you use irradiance map blending, it should be nice and flicker free.

I've never set my LC samples above 1600. Check "autosave", and also "switch to saved cache"

Hopefully that helps.

^^^FROM MATT TYREE, FOR JIM LAMMERS AT TRINITY ANIMATION