What is this?

[yeeha68]

What is this red paint ball?
It seems to be very random appearing on some cameras and some projects and not on others.
I have seen other people ask about simular problems and none of the replies seem to apply here. I am using "Apply Crop" image, all maps have a UVW map, and filtering is set to Pyramidal.
Dark multiplier=1.5
Sun=Target Direct@1.0


Here is another image with the same camera without the paintball. Why is that?

These are the settings

Any ideas???
-ken

[Dman3d]

Switch to scanline and make sure everything has UVW Mapping applied, make sure all bitmaps have "apply" checked in the crop area (in bitmap rollout -> material efitor)
Set bitmap filtering to none.
This did the trick once upon a time, Vlado probably fixed it and I am just wasting time doing it all.

[arobbert]

I've had those too. Increasing the irradiance map quality and changing the perspective slightly seemed to help. I think they call those angry photons.

[Dman3d]

That right! LOL

[proces2]

i had the same thing in one of my models. it turned out to be overlapping/criss-crossing faces. it was a tiny little instance in the corner of the model, but the second any light hit it - it projected the same red splotches all over the images.

sean

[yeeha68]

Ahh haa

There was an object at the corner by the red (a metal logo) that had an HDRI map in the reflection slot. The "map type" was set to "Angular." When I switched it to "Mirrored ball" it seem to solve the problem. Although I have experienced this before on other models without an HDRI reflection.

[dbuchhofer]

The absolute FIRST thing you do when you see these types of artifacts, is you open up the C:\VrayLog.txt file.. Scroll to the bottom, and check for errors in the range of "Overbright colors"

From there, check the materials attached to ALL objects that return errors.. Odds are you will notice one of 4 things..

a. The material has a specular level over 100.. (fine to keep, doesn't usually cause errors or splotches. Probably the only valid reason to have the error.)

b. The material is set to either Oren-Nayer-Blinn or Multi-Layer shading type.. Either of these CAN cause the problem, though they don't definitively have to.

c. There is a missing UVW on one of the objects

d. There is a bitmap in the material attached to that object that is 'leaking' so to speak.. clicking the Apply button in the crop options usually fixes it..

e. Lastly there is a 'Camera correction' modifier attached to the camera! This isn't just 1 angry photon though.. this is a veritable warground of splotches..

f. If none of them apply, strip the scene to its lowest common problem and send it to vray@chaosgroup.com

Those are the current causes/fixes/effects of splotches as of 1.09.02u. Reposting this one last time, just in case the 'splotches' posts fell off of the search engine..