Fabiano Berlim Posted June 26, 2008 Share Posted June 26, 2008 Hi Guys!!! I can`t make Global Illumination works in Mantra. I`ve been searching for this and I can`t find it. I was reading the post G.I. Workflow in Mantra ( http://forums.odforce.net/index.php?showto...al+illumination ) but something is wrong. So... I make a VEX Global Illumination... make a Light Tamplate... assign the VEX GI to Light Template SHADER... thats it... I have play with all the properties but it just give me back an AO. If I increase the tint I can get a little of color bleeding but that destroy the image. So... something is wrong. What am i doing wrong? Do I need to use photons to get GI with Raytrace and Micropolygon Render. If I need... how can I do that? With the PBR i could get a little better bouced light and color bleeding. But its too time costly. What do I really need to make a G.I. with a nice intensit of bounced light and color bleeding. Please help. I did not found that information on the internet. That are no tutorials to buy about advance mantra. And the manual don`t explain it properly. PS: Sorry for the nasty english!!! I hope you guys understand. Quote Link to comment Share on other sites More sharing options...
anamous Posted June 27, 2008 Share Posted June 27, 2008 Just to clarify: did you set the VEX GI Light shader to "full irradiance"? cheers, Abdelkareem Quote Link to comment Share on other sites More sharing options...
Fabiano Berlim Posted June 27, 2008 Author Share Posted June 27, 2008 Yes... I've been playing with all the properties. I just did no play with photons inside VEX GI. The results that Mantra gives me back it is very similar to the post "Mantra GI Workflow". And what I see in those pics do not look like a GI. Looks like a AO. Maybe Mantra its like that... I am not sure. Both Full Irradiance and Path Trace lit the scene with a sky light just like a AO. The diference of those two it is that they just make a little of color bleeding. If a dont want the sky lit and more intensit on the bounced light. what can I do? Of course... without using PRB. Here an example of what i am looking for. http://bp3.blogger.com/_togwyrdcnSs/SC2lM1...Trace_Small.jpg I took that picture from Jordan Tan`s Blog. http://pixel-samurai.blogspot.com/ That was made with Mantra Path Trace. I ask him how he did it. And he told me to come in here. Quote Link to comment Share on other sites More sharing options...
Fabiano Berlim Posted June 27, 2008 Author Share Posted June 27, 2008 Ok... I think that is working!!! Decrease the background color to black... increase global tint. SO... now I have one bounced raylight. To bounce more then one? Only PBR? Quote Link to comment Share on other sites More sharing options...
anamous Posted June 28, 2008 Share Posted June 28, 2008 Yes, in order to get more than one bounce you will have to switch to PBR. There is a theoretical option of setting the GI Light to "Path Tracing" mode and increasing the amount of diffuse bounces on the PBR tab of the Mantra ROP, but I'm not sure if that works so don't get your hopes too high up cheers, Abdelkareem Quote Link to comment Share on other sites More sharing options...
Fabiano Berlim Posted June 28, 2008 Author Share Posted June 28, 2008 Thank you!!! A lot!!! Quote Link to comment Share on other sites More sharing options...
symek Posted June 28, 2008 Share Posted June 28, 2008 (edited) Yes... I've been playing with all the properties. I just did no play with photons inside VEX GI. The results that Mantra gives me back it is very similar to the post "Mantra GI Workflow". And what I see in those pics do not look like a GI. Looks like a AO. Maybe Mantra its like that... (...) It's not Mantra, it's a shader you use (or irradiance() call in VEX). In fact VEX GI shader mix these two effects for some reason. This is perhaps perfectly accurate but not always what people are after in respect to GI. The issue is little weird and I think it would be great to involve some people to clarify GI workflow in Mantra starting from developers. Specially after SESI abandoned whole photon workflow in Mantra MP - what is pretty strange(!!!) PBR is great but can't be the only solution for GI in Mantra. *) Default VEX GI shader needs to deal only with first level rays what is done by a little clause at the beginning: if getglobalraylevel() == 0 Switching it to >= 0 changes a behavior of a shader for one you probably expect but leaves you also without irradiance cache - after that change samples don't fit to the image. There should be some workaround, but I'm not even sure where to go for that. Possible solution includes also leaving irradiance() call and writhing your own one with gather() loop, caching results with point clouds. * - This appeared to Andrzej Majewski here. Edited June 28, 2008 by SYmek Quote Link to comment Share on other sites More sharing options...
Fabiano Berlim Posted June 29, 2008 Author Share Posted June 29, 2008 SESI abandoned whole photon workflow in Mantra MP - what is pretty strange(!!!) PBR is great but can't be the only solution for GI in Mantra. Thanks a lot!!! SESI is leading Houdini to a more popular marketing approach... This is very cool!!! Now Houdini has a lot of stuff that makes things easly. But making it easy is not enough to the real learning. If SESI really wants to Houdini to be a lot more popular, they really need to make a bunch of tutorials in their site. GI and Mantra are good examples. I've bought all of Houdini's Digital Tutors, one Houdini CMIVFX, 3D Buzz Houdini Techinical Director, Magic of Houdini, and i've been reading a lot of things about Houdini, and I can't find good information on GI inside Houdini. All the other 3d softwares you just need to hit a button and you have GI. Of course, it doesn't need to be that easily, just needs to be easy to find those information. Making Houdini popular will get the attention of still 3d artists and small post companys, like mine. And that will be toaltally great!!! But it will be hard if they let aside already known workflows, like photons. Well, just some thoughts. Again... Thanks a lot for all the help and tips. I would like a lot to understand whats written in that site. But I am from Brazil, and not even english I speak properly. What language is that? So COOL!!!! Thanks!!! Quote Link to comment Share on other sites More sharing options...
symek Posted June 29, 2008 Share Posted June 29, 2008 (edited) All the other 3d softwares you just need to hit a button and you have GI. This is actually not true. Non of production reyes engies has ready to use GI workflow... What I was complaining about is that the status of old photon methods in micro-poly mode is unclear. Is it still supported or not? The behavior of photons generated in modern fashon (>H9) seems to be different so you can't use it in standard way. Well, you can, but it doesn't give you any quality. Long story.... cheers, sy. Edited June 29, 2008 by SYmek Quote Link to comment Share on other sites More sharing options...
Fabiano Berlim Posted June 30, 2008 Author Share Posted June 30, 2008 This is actually not true. Non of production reyes engies has ready to use GI workflow... What you mean about that? Well... just 3D Max have a poor native GI. But even being a third part software, Mental Ray is totallly integrated with XSI and Maya. Cinema 4D have Advance Render. etc Let me ask you something? Where do you work? Do you work for SESI or Digital Domain? If the photons is not working nicely, what is that photon map generation? Quote Link to comment Share on other sites More sharing options...
GallenWolf Posted June 30, 2008 Share Posted June 30, 2008 Non of production reyes engies has ready to use GI workflow... << 3dsmax -> Scanline Mental Ray -> Raytracing engine. none of them use the reyes engine.... so Symek is correct. GW Quote Link to comment Share on other sites More sharing options...
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