white spots on mesh

repete

Very puzzled as it's the first time this has occurred.

Any ideas of the cause ?

mAlkAv!An

This is a bug occuring in DX11 mode when using normal maps with TC_NormalmapUncompressed or TC_NormalmapBC5.

repete

thanks

yes I have been looking it up and found a workaround:)

cheers

r4ptur3

Just in case anyone stumbles across this thread --

I have had success at eliminating the problem by clamping my normal maps between .001 and .998 in their respective materials. I can confirm the problem only ever seems to happen in DX11 mode like mAIkAv!An said.

mAlkAv!An

Technically you should only clamp the blue channel, red and green need the full [-1,1] range.
However this will only remove NaN/white dots but artifacts (=black spots) remain. That's why I prefer to mask the red+green channel and simply append a scalar of 1 afterwards, at least with only little color information in the blue channel. This is also cheaper on instructions.

alfalfasprossen

the problem lies in how UDK derives the blue channel internally, do it yourself instead

r4ptur3

woah thanks guys

repete

Is it not strange that when lighting is not rebuilt the bug is not present ?

repete

For those of you who have this issue are you making changes to the DiffusePower by any chance ?

If I take another output from my diffuse texture sample and connect it to DiffusePower it recreates the problem a little and if I take the B channel output from the diffuse texture sample it's covered in white spots.

I am not convinced that it's a normal map problem, calls for more tests because it's only happening on some textures at my end. It could be a levels problem in the diffuse map aggravated by the normals.

repete

now I am almost convinced that it's the levels in the diffuse map.

below is the blue channel from the texture in the first 2 pics only here it's not tiled

mAlkAv!An

It's absolutely a normal map issue. Diffuse Power is only enhancing the effect.

repete wrote: »

, calls for more tests because it's only happening on some textures at my end.

Yes depends on the texture, I guess it's less of a problem for flat normal maps. You can however use sharpened MipMaps (Texture Properties -> Mip Gen Settings -> Sharpen10) to exaggerate artifacts for testing purposes.