My bezier clipping engine tests back
(L) [2006/07/04] [lmv] [My bezier clipping engine tests] Wayback!Handwritten trimmed beziers, sphere and triangle
<IMG title="" height=400 src="http://pics.livejournal.com/1xolmc1/pic/000101sf" width=400 border=1>
Couple Lightwave models converted to beziers:
Rhino, 163441 control points, 18150 bezier patches.
(model from MODO distribution, as far as I remember)
<IMG title="" height=300 src="http://pics.livejournal.com/1xolmc1/pic/00011w44" width=400 border=1>
Skullbot, 57655 CPs, 6396 bezier patches.
(free model from [LINK http://features.cgsociety.org/story_custom.php?story_id=1115&page=])
<IMG title="" height=600 src="http://pics.livejournal.com/1xolmc1/pic/00012r7h" width=600 border=1>
Elven queen, ~ half million CPs, ~100 or 200 thousand beziers.
This cutie was very detailed [SMILEY Smile]
<IMG title="" height=450 src="http://pics.livejournal.com/1xolmc1/pic/00013cy7" width=600 border=1>
(L) [2006/07/04] [Phantom] [My bezier clipping engine tests] Wayback!Image viewing was a bit difficult, but the images look fantastic... Welcome on the forum by the way!
Could you give some technical info on these images? What did you use to render them, and how much time did that take?
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Whatever
(L) [2006/07/04] [lmv] [My bezier clipping engine tests] Wayback!Thank you!
I'm sorry, what's wrong with images? They take too long to load?
These are outputs of my spare time engine which raytraces trimmed Bezier patches directly using Nishita's "Bezier clipping" algorithm.
I've rewritten it for SSE and added kD-tree to handle complex scenes. The main advantage - it takes a very little memory for storing complex scene, saving space for other things like photon map, etc.
But since there is no polygonization, splines remain smooth at any resolution.
Of course it's not realtime, but now it's fast enough for my experiments and I believe its speed can be improved in the future. Right now its just very basic program without complex materials, textures, etc. and I've just started to work on GI and realistic camera stuff.
Each scene has 64 point lights to test shadow ray speed... Kinda soft shadows [SMILEY Smile]
I can't remember info for Elven Queen right now.
For the first scene it takes about a minute 1200 x 1200.
For other images:
Rhino - 1600 x 1600
maximum tree depth: 21
Tree building took: 702 msec
Time spent: 04 min 11 sec 898 msec
Skull_bot - 2400 x 2400
maximum depth: 18
Tree building took: 327 msec
Time spent: 09 min 43 sec 636 msec
(L) [2006/07/04] [Phantom] [My bezier clipping engine tests] Wayback!Usually the forum software shows images directly when you put links in the message. In your case the urls are indirect, so I had to copy and paste them.
About the figures you mentioned: Tree building is very fast, especially that sub-second time for a 500k patch scene. Rendering times seem to be less optimal (even for 64 shadow rays per pixel); may I assume that you didn't use SAH for the kd-tree? Did you read about the recent avalanche of papers on a mix of kd-trees and bounding volumes? These structures can be build in times comparable to yours, but the speed is up to par with kd/sah. The hierarchy builder is also very easy to implement. Traversal is almost identical to kd-tree traversal, so I bet you can apply it in very little time to your tracer. That might be an easy way to speed up rendering.
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Whatever
(L) [2006/07/04] [Phantom] [My bezier clipping engine tests] Wayback!Hm... When I reply I *do* get to see your images automatically. Odd.
And about the faq: Sorry, there isn't one, we are just a friendly bunch of developers and researchers with an ad-hoc and informal forum and a passion for ray tracing. [SMILEY Smile]
About your timings: Seems I was wrong, if you use sah your build times are very respectable. I can't judge the other timings, I only have experience with triangles. But I believe Carsten Benthin mentioned rendering bezier patches, and he got pretty decent intersection speed. Then again, these weren't your trimmed beziers.
I really like that first image. Don't add textures please.
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Whatever
(L) [2006/07/05] [Phantom] [My bezier clipping engine tests] Wayback!Right here:
[LINK http://graphics.cs.uni-sb.de/~benthin/final.pdf]
There's more interesting recent material in the 'links and papers' section.
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Whatever
(L) [2006/07/05] [lmv] [My bezier clipping engine tests] Wayback!Thank you for information, it's just nice to find out something new about raytracing splines!
This site is a great source of information and I see cool people here!
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