Fabiano Berlim Posted May 7, 2009 Share Posted May 7, 2009 Hi guys, Just a question. Are Mario Marengo's Glass working with Houdini 10? I was testing the Glass and does not look like it still working. Thanks in advance!!! Quote Link to comment Share on other sites More sharing options...
Mario Marengo Posted May 7, 2009 Share Posted May 7, 2009 Are Mario Marengo's Glass working with Houdini 10?I was testing the Glass and does not look like it still working. support@sidefx.com That thing is now ancient, and I wouldn't at all be surprised if it failed in all sorts of spectacular ways with H10 (particularly with PBR). I would recommend using the built-in glass material if possible. Unless you're looking for some of the more esoteric features, I believe the bundled material does all the basic glassy things, no? Quote Link to comment Share on other sites More sharing options...
Jason Posted May 7, 2009 Share Posted May 7, 2009 support@sidefx.com That thing is now ancient, and I wouldn't at all be surprised if it failed in all sorts of spectacular ways with H10 (particularly with PBR). I would recommend using the built-in glass material if possible. Unless you're looking for some of the more esoteric features, I believe the bundled material does all the basic glassy things, no? Unfortunately the attenuation doesn't work under PBR with the shipped Glass shader, although it did receive some love for H10. For this you might have to use this shader. I hope SESI make their glass shader do this, sometime. Quote Link to comment Share on other sites More sharing options...
jason_slab Posted May 8, 2009 Share Posted May 8, 2009 nevermind the fact that there is no dispersion(yes i know i keep going on about this), i just don't quite get trying to do "physically based rendering" if you can't use physically correct shaders.... or maybe it's just me jason Quote Link to comment Share on other sites More sharing options...
Jason Posted May 8, 2009 Share Posted May 8, 2009 nevermind the fact that there is no dispersion(yes i know i keep going on about this), i just don't quite get trying to do "physically based rendering" if you can't use physically correct shaders....or maybe it's just me jason What makes you think they're not physically correct? Many of the shader are pretty close to being physically correct, if you think of them as emulations of measured empirical data. The only step missing from this solution might be that you're not using a library of measured materials, and the modeling of certain components like SubSurface transmittance and such. The whole idea behind PBR is the asking the renderer to come up with an accurate distribution based of illumination based on these models, which are based on physical empirical data. Mantra does this in RGB color space. There is a huge advantage to allowing the PBR engine to solve illumination for you. If you've written traditional shaders you'll very quickly find out where you might be grossly undersampling or oversampling your scene, continually seeking a balance between occlusion, reflection occlusion, diffuse environment, reflection, etc, ugh. Defining the BSDF to Mantra and allowing it to solve your illumination without you strong-arming it will result in overall faster and more accurate solves, if Mantra is doing the job right. If you're thinking that "physically correct" means that you should see spectral dispersion, you should realize that this is an immensely deep topic where Mantra would have to define colors in spectral color space (there is a 6-channel definition Mario uses, versus 3-channel RGB) and run the (more complex) math with that, and yielding a big slow down due the extra computations and conversions. I think we'll continue to push rendering to be MORE physically correct.. maybe even one day simulation the particle nature of light, along with diffraction patterns etc Quote Link to comment Share on other sites More sharing options...
Matt_K Posted May 8, 2009 Share Posted May 8, 2009 Man, I'd just like to be able to render at the speed of light! Quote Link to comment Share on other sites More sharing options...
jason_slab Posted May 8, 2009 Share Posted May 8, 2009 hey jason i understand what you are saying, i didn't or don't want to sound like i don't appreciate what PBR does, i fact i'm the only one in our office that is constantly "playing" with it! one of my goals in cg is to make photo-real renders, now without having a shader writer at hand, i do feel that i'm not getting the results i would like. yes i know physically correct is much slower, but it's much prettier:), also with the speed-ups in cpu's and multi-cores these renderers are becoming faster! jason Quote Link to comment Share on other sites More sharing options...
Jason Posted May 8, 2009 Share Posted May 8, 2009 yes i know physically correct is much slower, but it's much prettier:), I think I'm still confused by this statement:) Mantra PBR is physically correct. It just doesn't do spectral math at it's core -- which is just more physically correct. Quote Link to comment Share on other sites More sharing options...
jason_slab Posted May 8, 2009 Share Posted May 8, 2009 well that's pretty much what i mean:), "more physically correct" = "physically correct" in my books! jason Quote Link to comment Share on other sites More sharing options...
Mario Marengo Posted May 8, 2009 Share Posted May 8, 2009 Out of curiosity, and somewhat related, has anyone (Jason?, Anamous? ) had the time to seriously dissect pbr.h and play with all the new VEX-side engine-related functions? Too busy doing shots to try it myself so far, but after a brief look, it seems like we could do quite a bit of PBR damage using the new toolset (I'm thinking for dispersion and attenuation). Quote Link to comment Share on other sites More sharing options...
anamous Posted May 8, 2009 Share Posted May 8, 2009 I'm currently studying it and so far I have three plans for it: - Add a pointcloud based "irradiance cache" to the pbr_pathtrace() function - just like a photon map except that it's generated and evaluated on the fly - Abuse the sample_bsdf() function to output multiple passes - Somewhat related, I'm also currently changing the photon map generator to support a view dependent mode I've run across a few places where more physical effects such as dispersion would make sense. Love it! cheers, Abdelkareem Quote Link to comment Share on other sites More sharing options...
Mario Marengo Posted May 8, 2009 Share Posted May 8, 2009 I'm currently studying it and so far I have three plans for it:- Add a pointcloud based "irradiance cache" to the pbr_pathtrace() function - just like a photon map except that it's generated and evaluated on the fly - Abuse the sample_bsdf() function to output multiple passes - Somewhat related, I'm also currently changing the photon map generator to support a view dependent mode I've run across a few places where more physical effects such as dispersion would make sense. Love it! Woot! Sounds like a great plan (irradiance from pointclouds ought to be a standard with low-level support at this point IMHO -- an obvious and current application being emission from incandescent gases as in pyro). Please let us know how the experiments turn out! Cheers. Quote Link to comment Share on other sites More sharing options...
Fabiano Berlim Posted May 8, 2009 Author Share Posted May 8, 2009 support@sidefx.com That thing is now ancient, and I wouldn't at all be surprised if it failed in all sorts of spectacular ways with H10 (particularly with PBR). I would recommend using the built-in glass material if possible. Unless you're looking for some of the more esoteric features, I believe the bundled material does all the basic glassy things, no? In fact the glass shader is really good!!! As you guys said... don't have a proper absortion, only a tint. But, as you can see, it does the work. Is so bad that Mario's Glass does not work anymore. That was awsome!!! Quote Link to comment Share on other sites More sharing options...
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