View Full Version : Thought I'd share a story, written funny but true!

04-04-2005, 08:14 PM
A Beast Named Radiosity

Some say it was the raytrace recursions equals four, others believe that using caustics was my down fall. Nobody was ready for the horrible truth. But I could face it. I knew going into this render that I was playing with a dangerous beast. I knew the consequences could result in utter emptiness. I was not going to be stop by anything less than the blue screen of death himself. Render lights using Radiosity..... Enable! I was going for it!

Early the next morning I woke, expecting to find a full blown version of a three dimensional coaxial cable connector. Instead, to my great surprise arose the monstrous beast called Segment One of Two, Pass Three of Nine. Radiosity had struck again! The horrible truth is, Radiosity is a resource hog and we as Wam Bammers of the 21st century have no time to fiddle with such things. But I had to know.


04-05-2005, 12:39 AM
You need to optimse your scene and do small tests beofre you commit to the final render times.

Give Fprime a whirl for quick rad test renders.

Captain Obvious
04-05-2005, 04:53 AM
And never ever use Monte Carlo in Lightwave's renderer! ;)

04-05-2005, 05:00 AM
Or better yet, but F-Prime. ;)

04-05-2005, 06:06 AM
I think Matt means 'BUY Fprime'.

It really is very VERY good :)

04-05-2005, 06:19 AM
LOL!!! Yep, "buy" F-Prime!

04-05-2005, 07:51 AM
A Beast Named Radiosity...

I use Backdrop Radiosity + Textured Environment all the time. The Textured Environment mimicks the indirect light that normally bounces off of the sky and ground, and it makes my non-celshaded renders look drop-dead gorgeous with a minor render hit. Use a Gradient with an Input Parameter of "Pitch" to accomplish this effect.

Also, drop your Radiosity to 3x9. The default of 4x12 is major overkill and not worth the render hit. You can even drop it to 2x6 if you bump up the AntiAliasing to Enhanced High.

Keep experimenting. You'll love the stuff.

04-05-2005, 09:40 AM
Also if you do have "high reflective - less diffusive" objects (like metal and glass), using radiosity to them might be having not that big impact on quality but more on render times....

04-05-2005, 04:58 PM
Backdrop rad' is quite usuable, MC isn't, IMO!

But then, I use FPrime now anyway!

04-05-2005, 08:28 PM
Backdrop rad' is quite usuable, MC isn't, IMO!

But then, I use FPrime now anyway!

I'm too much of a wuss to touch LightWave's Monte Carlo, especially when I'm on a tight deadline.

I've seen other folks go for it, though. A supervisor once insisted on Monte Carlo. The huge render farm took care of the render times then.

I also saw another guy use it on two occasions. One instance was when he only needed to render out a still, so Monte Carlo's render hit didn't bug him at all. The other instance was when FPrime 1.02's render quality didn't look half as good as a native LightWave render.

FPrime 1.02 failed him when rendering a scene using this space station (http://www.celshader.com/dj/gallery/SpaceStation-50-003.jpg) and the planet Earth with three-bounce Monte Carlo rendering. He let it cook for weeks and weeks, and the noise never went away.

I'm certain that FPrime 1.5 would have handled the problem more quickly and gracefully on his dual-Opteron machine, but he did not have that option at that time. So, he turned on 3x9 Monte Carlo radiosity. With Enhanced Medium AA and Dithered Motion Blur, render times were 5 hours a frame.

A few days later he did another render test. He dropped the 3x9 Monte Carlo radiosity to 2x6 and bumped up the AA to Enhanced High. The 2x6 radiosity calculated much more quickly than 3x9. The extra AA passes smoothed over both the grainier radiosity and the Dithered Motion Blur. The render times dropped from 5 hours to just under 4 hours a frame, and they looked a lot better, too!

It'd be interesting to dust off that old scene and see if FPrime 1.5 does a less-noisy job with it. Still, if FPrime ever gets grainy, it's nice to have the LightWave render engine as backup. :D

04-06-2005, 07:03 PM
You guys are way over my head here but I'm going to play with this stuff and see what I get. Thank you all for the serious lessons!!


04-07-2005, 05:13 AM
You guys are way over my head here

Don't worry, man, it will come. ;)