snurre Posted March 15, 2015 Share Posted March 15, 2015 Hi all! I've been browsing around for the last few days, trying to find an answer to this, with no luck. I'm a noob, this will be my first post on cgarchitect. When I render my scene with material override things are looking good, but when adding my own Standard Material, light leaks are appearing. So I guess something is wrong with the material settings? (I've been trying to bump up the Irradiance map min. rate. with no success.) Also, can anyone explain what is the difference between a "Vray material" and a "Standard material"? Why is there no place for a bump map when making a "Vray material" I am using Vray with Rhino. Any suggestions would be much appreciated. Link to comment Share on other sites More sharing options...
inpow watir Posted March 15, 2015 Share Posted March 15, 2015 have you search here? http://forums.cgarchitect.com/showthread.php?t=77834 Light Bleed in 3DSMax/Vray Link to comment Share on other sites More sharing options...
snurre Posted March 15, 2015 Author Share Posted March 15, 2015 Thanks for the reply, but yeah, I've tried activating the retrace parameter with no luck. That guy is also having leaks even with the material override, so I suspect it's a whole different issue? Link to comment Share on other sites More sharing options...
Bruce Hart Posted March 16, 2015 Share Posted March 16, 2015 Try unticking the "Store direct light" option in the light cache for a start. If that does not fix it - Increase the subdivs in the LC and reduce the sample size. Also tick the "check sample visibility" in the IR. Before all of this check that the geometry does not have any actual gaps that lets light in. ....This has all been said before I know Link to comment Share on other sites More sharing options...
snurre Posted March 17, 2015 Author Share Posted March 17, 2015 Tried unticking "store direct light" in the light cache, increased the subdivs in the LC to 1500, and reduced the sample size to 0.1. Also ticked the "check sample visibility" in the IR. Still, the bleed/leak remains. The geometry has a thickness, and is walls/ceiling are overlapping. Tried using Brute Force as secondary engine, which seems to clean it up quite a bit. It's just very annoying not finding the cause of it all... Link to comment Share on other sites More sharing options...
inpow watir Posted March 18, 2015 Share Posted March 18, 2015 Chk normals? Link to comment Share on other sites More sharing options...
snurre Posted March 19, 2015 Author Share Posted March 19, 2015 Normals are fine Link to comment Share on other sites More sharing options...
snurre Posted March 19, 2015 Author Share Posted March 19, 2015 So as a final effort i bumped up irradiance map to 2, -2 The leak is quite gone, but I'm left with longer render times, and a more grainy image. If anyone has thoughts on how to tweak this, I'm happy to hear. In the mean time, I will go through a comprehensive tutorial on vray, as it is clear I need a deeper understanding of how the parameters interact. Link to comment Share on other sites More sharing options...
Francisco Penaloza Posted March 19, 2015 Share Posted March 19, 2015 Those light problems occur for two main reason, geometry or GI values. Sometimes materials may create them, like when you are using a very aggressive bump or displacement. If geometry is fine you need to see how you can optimize your GI, for instance, using sky portals in those windows will really help the sun or dome light get inside those rooms. Also there is a check box in V Ray materials when you are doing glass materials that help the light go through as it was a single panel, ( affect shadows). within Irr you can increase the number of samples and reduce the Nrm Thresh this usually help in tight corners, default is 3 or 4, using 2 will help. also Irr -3/0 should work most of the time, you need to increase your LC from 800 to 1800 or 2000, I also noticed you have 0 on number of passes, it is recommended to use the same number of cores to speed up the calc of LC. I would ask you to share the model to see if there is other problems but I am a Max user. V Ray basics are the same in all versions thou. The extra noise that you see, may be few samples in your materials or your DMC sampler is too height V/s Light materials samples. Link to comment Share on other sites More sharing options...
snurre Posted March 19, 2015 Author Share Posted March 19, 2015 Thanks so much Francisco! A lot of good pointers there, I understand most of what you are saying. May I ask what you mean by "you have 0 on number of passes, it is recommended to use the same number of cores to speed up the calc of LC." Link to comment Share on other sites More sharing options...
Francisco Penaloza Posted March 19, 2015 Share Posted March 19, 2015 from V Ray help "Number of passes - the light cache is computed in several passes, which are then combined into the final light cache. Each pass is rendered in a separate thread independently of the other passes. This ensures that the light cache is consistent across computers with different number of CPUs. In general, a light cache computed with smaller number of passes may be less noisy than a light cache computed with more passes, for the same number of samples; however small number of passes cannot be distributed effectively across several threads. For single-processor non-hyperthreading machines, the number of passes can be set to 1 for best results." http://help.chaosgroup.com/vray/help/150SP1/render_params_lightmap.htm So if you have a single quad core i7, your number should be 4, if is is Hyperthreaded, that number should be 8 and so on. Not strictly necessary but it help Link to comment Share on other sites More sharing options...
inpow watir Posted March 24, 2015 Share Posted March 24, 2015 0 in LC pass means auto. It will matchs with your threads count automatically. cmiiw but this is another issue :-) Link to comment Share on other sites More sharing options...
Bruce Hart Posted March 25, 2015 Share Posted March 25, 2015 Tried unticking "store direct light" in the light cache, increased the subdivs in the LC to 1500, and reduced the sample size to 0.1. Also ticked the "check sample visibility" in the IR. Still, the bleed/leak remains. The geometry has a thickness, and is walls/ceiling are overlapping. Tried using Brute Force as secondary engine, which seems to clean it up quite a bit. It's just very annoying not finding the cause of it all... Hey again Did you mean a LC sample size of 0.1? It should be 0.01 Link to comment Share on other sites More sharing options...
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