dynaman Posted July 28, 2006 Share Posted July 28, 2006 Hey guys, I'm hoping someone might be able to help me out here. I've been a vray dabbler for a while and decided to try it on a production project. I feel like I'm getting a grip on the controls, but I am getting a recurring problem (on this project) that I just can't fix. If you look at the attached previews, you will see the problem - big white splotches appearing in seemingly random places in the image. I have been using IR for primary and QMC for secondary. As you can see, the problem persists whether I use very low preview settings, or higher production settings. In the 2nd exterior shot, I rendered only the region in question after hiding the entry wall. I even turned down a bunch of lights inside, and still the blowout. A few other details about the scene: - all materials vray - no glossy reflections - a few vray area lights (creating glow from back and front of space) - 45 max standard spotlights, using vray shadows - 6 non-shadow casting omnis to brighten the space I have tried turning on and off all possible global switches to isolate the problem, but it only occurs when all my settings are on. I would be immensely greatful to anyone who can help. I am getting down to the wire to get this completed, and this is really holding up the process. I will gladly send anyone this scene if they would like a closer look. Thanks in advance!!! Link to comment Share on other sites More sharing options...
dynaman Posted July 28, 2006 Author Share Posted July 28, 2006 hmmmm... Follow up to my own question: Is it possible that the non-shadow casting omnis could have something to do with it? I tried assigning them vray shadows, and for the moment the problem seems to have gone away. I haven't done enough test previews to say for sure, but maybe??? Link to comment Share on other sites More sharing options...
dynaman Posted July 29, 2006 Author Share Posted July 29, 2006 In doing some sleuthing, I discovered a few more possible culprits for the light splotches. For one thing, I noticed that I was getting series of warnings about "material returned overbright". I found in some previous threads that people had warned that max material specularity could be causing intense light spots, due to the fake specularity bouncing light onto other surfaces and screwing up the IM. I'm using all vray materials, but does anyone know if you unlink the "hilight glossiness", and essentially create a fake vray specularity, can this create the same bounced light problems that mess up the IM? ...(why do I feel like I'm talking to myself?) Link to comment Share on other sites More sharing options...
dynaman Posted August 1, 2006 Author Share Posted August 1, 2006 Well, in case this helps anyone else... I have more or less figured out the problem. It doesn't appear to have been one single part of the scene, but more likely a combination. There turned out to be 4 pieces of geometry that were getting the "returned overbright" warning. Sure enough, if I hid them, the splotches disappeared. Although this didn't solve the problem, it helped to narrow it down. I went through my material palette and made sure any white materials didn't have the brightness value higher than 230. That went for both vray materials, and vray light materials. This didn't completely fix the problem, but seemed to help. I had six non-shadow casting omnis in the space to brighten it slightly. I tried giving them vray shadows, and this fixed the problem completely, however it made some strange shadow lines. So I tried turning them off and I found that the scene was still bright enough, and the splotches were gone. Finally, there were a few pieces of geometry in the scene that had been built for a previous version of the model, and they were listed in the overbright warnings. I rebuilt these pieces, and no more warnings. So anyway, I don't know if it was one particular element causing all the splotches, or the combination of a few problems. Here's the latest result... Link to comment Share on other sites More sharing options...
mooney102 Posted August 1, 2006 Share Posted August 1, 2006 I'm listening I seem to be having the same problem, but these splotches are inconsistent. Whenever I reload the original project in, all settings seem to change. Lights get brighter, splotches appear. I am using a simple vanilla vray mat for all objects except glass. This is for camera pathing aproval. I am using LC and IR. When rendering single frame for both maps, the final render turns out just fine. When sending out to farm in three seperate files the image returns splotchy. Any Ideas Link to comment Share on other sites More sharing options...
dynaman Posted August 1, 2006 Author Share Posted August 1, 2006 sorry - it sounds like a different type of problem. i've been doing all my rendering locally so i can't help there. i haven't had much success using LC for secondary bounce. i usually find it produces kind of blotchy results. you might try switching to QMC, but i'm pretty new to this. still, what helped me was trying to reduce variables. i changed the settings for materials, lights, and rendering in an effort to isolate what was producing the problem. sounds like you could eliminate material right away... Link to comment Share on other sites More sharing options...
FlytE Posted August 2, 2006 Share Posted August 2, 2006 right click and convert scene to vray materials. Also, make sure that in your reflection or refraction, eg glass, you dont use pure white (value 255 255 255), make it just less at 254. Link to comment Share on other sites More sharing options...
mooney102 Posted August 2, 2006 Share Posted August 2, 2006 The glass Mat is not pure white, it is (254,254,254) for reflection and refraction. I also right clicked, vray scene converter, and changed all materials to vray. The light spots still appear. They are in different locations for almost every frame. Link to comment Share on other sites More sharing options...
FlytE Posted August 4, 2006 Share Posted August 4, 2006 I didnt notice, but your man already seems to have solved it. Lights without vray shadows in comb with bad geometry seems to be the problem? Something I also noticed that sometimes helps is if you select all the vertices of the geometry with the problem and weld them. This has on occasion helped me - i think it seals the geometry better or something.... Dynaman, by and chance was it previously modelling in autocad and imported? Link to comment Share on other sites More sharing options...
mooney102 Posted August 4, 2006 Share Posted August 4, 2006 The problem was definitly a combination of issues. After converting all materials to vray, I found a material that was not even used that had a pure white value. Changed those things, and it worked fine. Thanks for the help guys, patience was wearing. Link to comment Share on other sites More sharing options...
David Knourek Posted August 4, 2006 Share Posted August 4, 2006 my bad posted in wrong thread -dave Link to comment Share on other sites More sharing options...
mooney102 Posted August 4, 2006 Share Posted August 4, 2006 No Problem. Link to comment Share on other sites More sharing options...
carlangas Posted August 4, 2006 Share Posted August 4, 2006 hey Mark sorry to jump in this late in the thread but have you tried checking off the "ShadeContext compability" box in the vray system roll out? this has helped me when getting white slpotches....you should probably check the chaos forums as well, they often have more detailed info for all types of problems Link to comment Share on other sites More sharing options...
dynaman Posted August 4, 2006 Author Share Posted August 4, 2006 guys, thanks for the follow-ups. carlos, yes that button was checked. i think it is on by default? flyte, good suggestion about the welding. i will definitely give that a try in the future. i'm not sure what software was used to model, perhaps max but by a rookie with weird techniques. mooney, glad to hear you got rid of your splotches too! Link to comment Share on other sites More sharing options...
Jefferson Grigsby Posted August 10, 2006 Share Posted August 10, 2006 Material returned overbright is an error you get when using any non-vray material. Link to comment Share on other sites More sharing options...
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