Cinema4D R11 Just popped out and I've been trying to render a nice smooth animation lit completely by an image. Lighting by an image is a true test of a GI engine as it requires great precision, when you have interpolation like with Irradience you tend to get bad glitches and shadows that don't quite fit the corners of objects. Fortunately we have BruteForce and QMC which give the nice noisy versus blurry effect such as you might get with unbiased renderers like Maxwell.
So to summarize what I learned, use Irradience for most cases when dealing with large undetailed flat areas, but if you get problems with glitches and shadows not being sharp enough/meeting edges then switch to BruteForce
And remember that rendering 5x the size with Irradience will render at the same speed if you cache the GI, Brute Force however will take much much longer making it hard to justify for Print resolution work.
This render I did took all night but It's pretty good (the visible stepping is from compression):
Oooh ooh, I just found something, I thought this was coming in a future version but It's included and working right now! why did no one tell me!
You can use an image to power an area light:
1:17 Area Light (20) + Low GI + DMC AA 4
5:39 Brute Force (40) + Light Cache (1000) + DMC AA 4
2:53 Vray BruteForce
3:00 Vray Irradience
Vray's BruteForce isn't always better here It's over 4x times slower and visibly noisy so to get a smooth result would probably take twice as long again.
Even so, you can see the corners on the cube are sharper, but It's just not important here.
Also BruteForce solutions can't be saved and re-used. This is especially useful when rendering at very large sizes for print.
Vray Irradience - Rubbish but fast
Vray Irradience - Nicer but slow
Vray BruteForce - Spangly but even slower
I'm revisiting a bunch of old render I did years ago to use my new found skills, computer and rendering engine to make them sexy again by modern standards (I hope)
Versus the Old:
Versus the Old:
And while I'm doing all this revisiting, I just realized my website is full of bugs!!! Stuff I must have introduced when I 'fixed' it to smooth images thanks to a glaring omissions in Flash back when I created the site.
Oh well, I'll get round to that later, I did at least just add sorting my work by date, so now the newest stuff appears first which embarrassingly took an hour to do.