sdfresh Posted February 25, 2013 Share Posted February 25, 2013 Does anyone have any idea what these faceted highlights are caused by. I am using 3ds Max 2013 with V-ray and have a simple V-ray sun and sky lighting system with one additional standard spot. They are not affected by materials values as far as my tests have gone but can be greatly reduced by increasing geometry resolution. They can also be influenced by adjusting the shadow bias on the sun. I am happy to load the scene if it helps. Many thanks, Adam Link to comment Share on other sites More sharing options...
cg_Butler Posted February 25, 2013 Share Posted February 25, 2013 What shadow options do you have on your standard spot? Are they on VRay shadows? If you increase your sun bias, do they disappear? It actually gives quite a cool look! Link to comment Share on other sites More sharing options...
sdfresh Posted February 26, 2013 Author Share Posted February 26, 2013 I know, for another application I would probably pull my hair out trying to achieve this effect. Sod's law it raises its head when I dont need it. The spot seems to be irrelevant as the shadows persist even when it's deleted. I also have a sphere (inverted normals) around the object with a light material applied to give reflections that also seems to be irrelevant. This leads me to believe it has something to do with the antialiasing filters or the light cache or most probably the sun itself. Stuck! Link to comment Share on other sites More sharing options...
cg_Butler Posted February 26, 2013 Share Posted February 26, 2013 (edited) Could you upload the file? I'll take a look..... It doesn't look likt a typical LC or anti aliasing problem to be honest..... It's more likely going to be face normals or shadow bias or co planar faces. The way it reduces or increases makes me think it's the shadow bias and co planar faces together..... Edited February 26, 2013 by cg_Butler Link to comment Share on other sites More sharing options...
sdfresh Posted February 26, 2013 Author Share Posted February 26, 2013 OK, makes sense. Would be really interested to see you take on this as it's beyond me at the mo. As I mentioned the scene is pretty simple so hopefully you'll find a simple fault. Zip file should be attached below. Twist 2.zipTwist.zip Link to comment Share on other sites More sharing options...
cg_Butler Posted February 26, 2013 Share Posted February 26, 2013 Could you save it as a 2012 version.......i can't open it so assume your running 2013... Link to comment Share on other sites More sharing options...
sdfresh Posted February 26, 2013 Author Share Posted February 26, 2013 Sorry I thought i saved it as a 2010. Obviously not. Twist.zip Link to comment Share on other sites More sharing options...
cg_Butler Posted February 26, 2013 Share Posted February 26, 2013 Simples....... It is your shadow bias. THis option move the shadow towards or away from objects. Values that are too smal (especially negative values) can do funny things. I'd pop it on 0.1. Here is an explanation on from the vray help. Shadow bias is at the bottom. Shadow bias VRay help In my experience I've never used negative values. The lower the value the closer to the object the shadow is so as a minimum i'd use 0.1mm. You'd never want the shadow to be behind an object. When I render with 0.1mm i get this. Link to comment Share on other sites More sharing options...
sdfresh Posted February 26, 2013 Author Share Posted February 26, 2013 That is pretty darn "simples".... To be honest I've never worked with V-ray sun or shadow bias and so i am not quite sure how I ended on this odd number. The only rational I can give is that the more into the negative I went with this figure the better the lighting looked and the very best was exactly around the figures where the pixelation started. For instance in these negative values the highlights (or rather the lack of shadow) behind the central twisting piece disappeared. By that i mean it was all shadow rather than seeing the full light and shadow. So, with this is mind do you think it would be better to simply more the sun until the desired effect was achieved. Or to tweak the bias to the same end. Either way, thanks for clearing up this anomaly... Much appreciated Link to comment Share on other sites More sharing options...
cg_Butler Posted February 26, 2013 Share Posted February 26, 2013 No problem. It's definitely better to keep the shadow bias at positive values and move the sun around so you get the shadow angles you are after. Then if you want some specular highlights add in another light or two to give these. :-) Link to comment Share on other sites More sharing options...
sdfresh Posted February 27, 2013 Author Share Posted February 27, 2013 Great, well then we're done. Thanks for your help on this, much appreciated. Adam Link to comment Share on other sites More sharing options...
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