peliosis Posted January 12, 2006 Share Posted January 12, 2006 I have never used prman and probably this will continue for some time:), but I'm interested how fast it's raytracing is when compared to mantra. As they have accelerated raytracing, are all these gi, caustic, sss things comparable to new speed standards set by vray? Mantra GI is a bit slow yet (compared to renderman compliant AIR for example), but how does it look when compared to prman. If somebody could make a fast comparison between mantra and prman in houdini I'd be grateful. Quote Link to comment Share on other sites More sharing options...
deecue Posted January 12, 2006 Share Posted January 12, 2006 check out the houini 9 wish list thread: http://odforce.net/forum/index.php?showtopic=3472&st=110 Quote Link to comment Share on other sites More sharing options...
Jason Posted January 12, 2006 Share Posted January 12, 2006 check out the houini 9 wish list thread:http://odforce.net/forum/index.php?showtopic=3472&st=110 23610[/snapback] I have this from an old test I've done with: Mantra 8.0.473 * RAM: 517mb * Time: 30:13 Prman 12.5.2 * RAM: 740mb * Time: 31:05 Scene: ~900k polygons 64 samples ambient occlusion no motion blur Conclusion: Without any acceleration at all in Mantra or Renderman (i.e. no cache), Mantra is a little faster and uses less RAM for *very* comparable quality renders. Not bad! Quote Link to comment Share on other sites More sharing options...
peliosis Posted January 13, 2006 Author Share Posted January 13, 2006 Wow, what are the reasons to use prman instead of mantra than(if not motion blur)? Do you use prman in production of such great commercials like guiness or is mantra sufficient? Until I tried houdini I didn't think occlusion is such a big rendering deal, I used xsi and there is a dirtmap shader to calculate occlusion. The whole thing was so fast that I never really had a look at rendering time. Thanks for a comparison Jason, It's sort of prman demistify for me:) Quote Link to comment Share on other sites More sharing options...
Jason Posted January 13, 2006 Share Posted January 13, 2006 I can post a motionblurred version for you too, no problem. Gimme 40 mins. From Houdini we use Mantra 95% of the time - only reverting to Renderman for rendering deepshadows that get fed into Terragen, Storm and to mesh with renders from Maya/MTOR. Quote Link to comment Share on other sites More sharing options...
Jason Posted January 13, 2006 Share Posted January 13, 2006 Motionblurred version, 6x6 samples Mantra: * RAM: 509mb * Time: 49:56 PrMan: * RAM: 748mb * Time: 1:16:47 Quote Link to comment Share on other sites More sharing options...
DaJuice Posted January 13, 2006 Share Posted January 13, 2006 nice! I'm surprised how few samples you can get away with for such an amount of mblur. Mantra's motion-blur always struck me as pretty fast, I guess this confirms it, what with prman's reputation for fast mblur. Quote Link to comment Share on other sites More sharing options...
Jason Posted January 13, 2006 Share Posted January 13, 2006 nice! I'm surprised how few samples you can get away with for such an amount of mblur. Mantra's motion-blur always struck me as pretty fast, I guess this confirms it, what with prman's reputation for fast mblur. 23641[/snapback] Thats true. Mantra's quality and speed have leapt forward since version 8 and to be honest, I prefer the quality of the image. I find the there is slightly less noise and better sampling in Mantra than in Prman now. I think with version 8 that Mantra is a real contender in the PrMan world. Another challenge for everyone is to test motionblur and DOF combined and compare the differences. I've had great results with this in Mantra 8... try it. Quote Link to comment Share on other sites More sharing options...
Andz Posted January 13, 2006 Share Posted January 13, 2006 I prefer the quality of the image. I find the there is slightly less noise and better sampling in Mantra than in Prman now. 23642[/snapback] I agree about the less noise in Mantra image. Is that a blueshift on mantras motion blur? Quote Link to comment Share on other sites More sharing options...
stu Posted January 13, 2006 Share Posted January 13, 2006 I completely agree that prman doesn't have an advantage over mantra when it comes to hard bodied surfaces. Where the current incarnation of mantra starts to suffer is in the very complex - hairy characters, grassy fields, multiples of millions of primitives, etc. I understand that this will be addressed in the next release however... Quote Link to comment Share on other sites More sharing options...
peliosis Posted January 13, 2006 Author Share Posted January 13, 2006 That are very good news. But still for a small studio rendertime exceeding 10 minutes per frame can be fatal:) I hope next mantra will have faster GI and raytracing, so we could use only houdini for rendering. Have enough using that bloody max just for vray. Quote Link to comment Share on other sites More sharing options...
Jason Posted January 13, 2006 Share Posted January 13, 2006 That are very good news.But still for a small studio rendertime exceeding 10 minutes per frame can be fatal:) I hope next mantra will have faster GI and raytracing, so we could use only houdini for rendering. Have enough using that bloody max just for vray. 23658[/snapback] I think Mantra will only be getting better from here - there is a undeniable value in improving mantra further in this area. Quote Link to comment Share on other sites More sharing options...
keltuzar Posted January 13, 2006 Share Posted January 13, 2006 hmmm regarding the motion blurred test.... if you used prman's pcmap baking method, wouldnt that not reduce ur rendering time to like half? for objects that arent deforming at all baking out an occlusion pass and using it agian is probably more efficient since both manta and prman are reyes primarily.... Quote Link to comment Share on other sites More sharing options...
Jason Posted January 13, 2006 Share Posted January 13, 2006 hmmm regarding the motion blurred test.... if you used prman's pcmap baking method, wouldnt that not reduce ur rendering time to like half?for objects that arent deforming at all baking out an occlusion pass and using it agian is probably more efficient since both manta and prman are reyes primarily.... 23665[/snapback] The intention of these tests here was to compare raw architecture. Both renderers have very good caching methods which both require various level of tweaking and could very well speed up renders 2-3x easily. I am not familiar enough with the latest renderman techniques for accelerating renders and don't have the time it takes to get the optimum speed out of it. It wouldn't be fair for me to use mantra caching methods and not renderman, right? This is basically a display of brute force raytracing and motion-blur algorithms in action. Quote Link to comment Share on other sites More sharing options...
Jason Posted January 13, 2006 Share Posted January 13, 2006 Here is a DOF test - no motionblur, 8x8 samples, 1 keylight with shadowmapping. Mantra and PrMan both did it in ~3:20s, Mantra with the same RAM difference as the previous tests. These images are extraordinarily similar, quality wise. Quote Link to comment Share on other sites More sharing options...
keltuzar Posted January 13, 2006 Share Posted January 13, 2006 my intensions was to see how long it would take when a test with baked occlusions was used in both the renderers.... also I found a very odd artifact when I use prman that shows up in your ship renders; is the white outline at the base where it nearly touches the ground.... Quote Link to comment Share on other sites More sharing options...
peliosis Posted January 13, 2006 Author Share Posted January 13, 2006 my intensions was to see how long it would take when a test with baked occlusions was used in both the renderers....also I found a very odd artifact when I use prman that shows up in your ship renders; is the white outline at the base where it nearly touches the ground.... 23669[/snapback] What exactly do you mean by "baking occlusion"? Rendering to texture and applying that texture as constant, or storing and reusing the samples? I'm not sure if texture baking is used extensively but If there is other method than applying uvs and constant material to every single object please enlighten me:), because last time I did it (architectural animation in XSI) it was horrible amount of manual work. Quote Link to comment Share on other sites More sharing options...
Jason Posted January 13, 2006 Share Posted January 13, 2006 That's just raytracing bias. (It sends the ray from just a tiny distance off the surface to avoid self-intersections - and this is why it missing at the edge.) My scene is not the "correct" size either. My bias is 0.05 and the entire ship is fitting into a unit or two - which is pretty bad for numerical accuracy really. The bias is relatively large compared to the ship size. I expect artifacts like this with these values. Quote Link to comment Share on other sites More sharing options...
Jason Posted January 13, 2006 Share Posted January 13, 2006 DOF with motionblur: Mantra * Time: 9:15 PrMan * Time: 10:30 .. and the speed diiference gets greater the more motion-blur and dof effect you have. Quote Link to comment Share on other sites More sharing options...
sibarrick Posted January 15, 2006 Share Posted January 15, 2006 For those interested in this from a "Dirt Map" perspective you might be interested in this hack. It does the occlusion calculation on the geometry before rendering. Obviously the quality is nothing like as good as a full render but just for dirt map type applications it's very acceptable from certain types of geometry. Occlusion.zip Quote Link to comment Share on other sites More sharing options...
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