Weak imported vertex color

Eric Chadwick

Anyone know why vertex color imported via FBX from 3ds Max is super weak in UDK?

Even if I plug it directly into Emissive, it's very weak, like pastel colors.

blankslatejoe

hmmm...try and reimport manually (by importing the same name over itself) and choose the 'reimport vert colors'. Maybe it's stuck with old colors.

Also, is this in the mat editor or in the game viewport. In the game viewport, be sure to check it in unlit, or else you may be getting the scene lighting stacked ontop of your vert colors (unless your material is unlit, of course)

Eric Chadwick

Naw, original import seems fine. It seems the interpolation is very different in UDK, maybe a gamma curve?

LoTekK

That's definitely gamma. If you do a levels on either side and put the midpoint at 2.2 (left side) or 1/2.2 (right), you get identical colors. Not sure why the vertex colors are being gamma corrected, though, or where to tell max not to do so. Worst comes to worst you could do a gamma correct in the material setup (pow 0.45454).

LoTekK

[doublepost]

Eric Chadwick

Hmm. The colors themselves aren't different. It's the interpolation that's different. I guess there's gamma in UDK's rendering process somewhere?

Ace-Angel

As far as I know, everything is being GC'ed in UDK when it comes to color.

Did you try and run a comparison between UDK's vertex paint tool and what colors it gives you?

You could take your vertex color in your material, multiply it by a bigger number then 1 (and power it as Lotek said) and clamp it before feeding it into the final setup?

I'm not sure if anything I'm saying will help.

EDIT: Oh wait, when importing it, what are the option you have ticked?

Eric Chadwick

I'll try the UDK meshpaint tool, good idea.

I can put a fix in the material, but I'd rather understand why I'm getting the result.

Import Type: Static Mesh
Override Full Name = on
Preserve Smoothing Groups = on
Replace Vertex Colors = on
Create Groups Automatically = on

Ace-Angel

Try Disabling "Replace Vertex Colors" and toggling "Remove Degenerates".

Eric Chadwick

Disabling "Replace Vertex Color" causes the vertex color to not be imported.

"Remove Degenerates" causes errors with the vertex normals.

But thanks anyhow. I guess I'll just use LoTekK's pow .45454 in the material.

lpcstr

I tried it with Blender and everything works as expected. Clearly 3DS uses sRGB color space instead of linear. Instead of trying to correct it in the shader (wasteful) instead see if you can configure 3DS to use linear color values instead. If 3DS can't do that, then simply take into account the difference between sRGB and linear when choosing colors in 3DS.

System

this literally blew my mind. so is there a way to create a more diverse amount of vertex colors? I find that blending even with two textures it immediately goes to the middle value.

It would be really nice to be able to control vertex colors interdependently wouldnt it?

System

so assuming that this is a pretty standard bilinear interpolation the colors look something like this correct? http://upload.wikimedia.org/wikipedia/commons/c/c6/Bilininterp.png

Is there anyway to avoid such a large "orange and yellow" area?