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radiosity without radiosity


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  • Hash Fellow

I'm reading Jeremy Birn's book "Digital Lighting and Rendering" and trying some of the stuff he talks about.

 

This is a room lit with just simple z-buffered kleig lights. This renders in 75 seconds.

 

RoomTestB0.jpg

 

 

The one in the book is much better but I'll get there.

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  • Hash Fellow

Here's the book. It's the world's foremost guide to CG lighting. He says so in the introduction. ;)

 

It's not a set of step-by-step tutorials but more of a discussion of concepts and how basic techniques are used for different purposes. It's mostly application non-specific, but after I finish it I may write a set of annotations to translate the few things that are different in A:M. For example, what he calls a "point light" is a "bulb light" in A:M. The good news is that A:M seems not to be lacking in CG lighting tools.

 

I'm only on the second chapter but I'd recommend it to someone who is wondering about lighting. Make sure you get the second edition.

 

 

Here are the lights in my shot

 

roomChor.png

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  • Hash Fellow

Here's another tactic. This uses a light on a spline in the shape of the spot of sun on the ground for the bounce off the floor and another traversing a hemisphere spline outside the window for the sky light. Fewer lights but they are jittered over more angles. Still just Z-buffered Kleig Lights

 

roomWire.png

 

 

more passes gets smoother results

 

16 passes 1:27

RoomTestJ_16passes__1min_27sec.jpg

 

 

49 passes 3:44

RoomTestJ_49_passes_3min_44sec.jpg

 

 

100 passes 7:25

RoomTestJ_100_passes_7min25sec_.jpg

 

 

256 passes 19:14

RoomTestJ_256_passes_19min14sec.jpg

 

 

Those are not bad times for nuanced lighting effects. It's entirely possible that with more lighting skill those times could be cut down.

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  • Hash Fellow
is there possible to get the file?

 

It's very basic. I'm sure you'd enjoy making you're own. ;)

 

but here you go:

 

Room09c_AllEmbedded.prj

 

 

 

 

 

 

Here's an actual radiosity render of the scene, lit by just the light hitting the floor. This takes 1 hour 27 minutes.

 

RadTestA.jpg

 

I'm sure this could be improved if I added the light of the sky coming thru the window. I suppose I'd have to do a skydome for that. But I can look at this and see how close I came with my artificial lighting to what the simulation did and adjust my lighting to mimic it more closely if I like the simulation.

 

But even the 256 pass render is quite a bit faster than the radiosity render for a similar effect. That's very interesting to me.

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  • 5 years later...

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