material return overbright!!!!

[odi120522]

Hi to all....hope you can help me with my problem....i am new to vray...and i am using irradiance map for my 1st bounce and light cache for 2nd bounce...whenver i render there is a warning message that goes like this..WARNING MATERIAL RETURN OVERBRIGHT!! IS THERE ANY WAY THAT I CAN SOLVE THIS PROBLEM...OR USUALLY WHATS CAUSING THE MATERIALS TO GO OVERBRIGHT??? is that ALSO the reason why i am having a message of INVALID LIGHTMAP SAMPLES??? TNX IN ADVANCE....

[diegofer_9]

Hi,

I am not completely sure, but I used to have a similar problem when I started with vray and it was most of the times a raytrace material or a material with raytrace reflections in the scene. Raytrace materials or reflections and vray dont go together. Hope this helps.

[jophus14]

Diegofer_9 is right. Do not use any materials that have raytrace in them. Try to use only Vray materials if possible. If your scene is using only Vray materials, you can ignore the warning. It should render out just fine

[Hoa Dinh]

sometime when you used PRC....

[frank1331]

I've run into this overbright problem a lot. Usuall it doesn't effect the overall rendering quality. Just makes you nervous when you see it. I have found that it happens a lot with glass materials and anything you have as a pure white material. If you have white materials, tone them down a little, nothing is pure white in real life. (Well not for long at least, things get dirty.) As far as the glass material, I only use vray free so I don't have access to vray materials, but I found that if I change the ambient light of the glass to black, the error warning goes away.

 

Hope it helps

[bricklyne]

In my experience there usually 2 glaring causes of this problem.

1) As has been pointed out before, try to avoid having any pure white (255,255, 255) materials in your scene. They don't exist in real life and Vray doesn't like them. Typically it wouldn't cause a problem with the render other than just giving you that error message, but sometimes you can get problems when using Lightcache or Irr. Map GI methods.

2) USing certain types of glass and glossy materials with a fall-off map in the reflection slot, is a really really big culprit. Fall offs usually increase the accuracy of the reflection but, at the same time causes a bug with Vray. Certain material collections (most notably deletee) have this problem. With this cause, your render can completely collapse and not calculate or render secondary GI bounces leaving the render looking very dark or black. All you have to do is get rid of the falloff map or use a different glass material with a simple plain diffuse reflection slot. It took me long while and a lot of frustration before I was able to discover this and I really hope it helps.

[ShaunDon]

Don't know if anyone else does this, but I also used to pump up the output of the diffuse map to make a vray material glow. Unfortunately if you pump it up by ~5 or more, vray goes overbright berzerk. Just had a tiny bulb portion of a downlight blow out my whole scene when the lc was calc'd to 3000 subdivs. If you do output that high for some reason, just make sure you wrap the material and crank down the GI output for it.

 

Also, in your VRay log, often times the very first object or map to report an overbright is the culprit -- the ray then cascades the overbright everywhere else. So start at the first object it names, if that looks okay, go to the next, and so forth... That works most of the time for me.

 

Shaun

[odi120522]

Thanks alot guys for your tips and advice....ill keep those things in mind,....sorry for late reply...thanks again....