BlendMode Modulate not supported?

[Tom Ellis]

Hey there,

I'm just trying to setup a decalMaterial and last time I did it, I'm sure I just plugged in my diffuse and set the blend to modulate. However I just downloaded the June UDK (I was using an old build prior to this) and now I get a message saying it can't use modulate with dynamic lighting.

I Googled and found Metalliandys answer to a similar question over on Eat3D but I didn't fully understand his solution, which was to invert the diffuse and use BlendMode Translucent.

I tried inverting each of my diffuse channels in Photoshop (which is just 3 black/white images plugged into R,G,B to get 3 maps out of 1 tga) but this just resulted in a black plane.

I'm clearly doing something wrong so any help would be much appreciated!

Thanks

[divi]

he inverted his diffuse because they are b/w and can be used as a opacity map for the translucency. if your decals aren't b/w that obviously won't help you a lot. depending on what the decal look like you could extract a mask from the diffuse by clamping values, but you are probably better off just using an alpha...

so yeah, diffuse in the diffuse slot, alpha in the opacity slot and blend mode to translucent.

[Tom Ellis]

Thanks Divi,

Yeah my diffuse maps are grayscale, I'm just using the RGB channels of a TGA so I can get 3 different diffuse textures out of a single TGA. The plan was to create 3 materials, and then the R into the diffuse of the first, G into the diffuse of the second etc.

I was hoping to do it without a mask but if that's the only way then I guess that'll have to do!

Thanks again

[divi]

ah, now i understand your problem :D should've read your first post more carefully.
i would use the texture sample only for the opacity and do the color of the decal with a constant. that way you can avoid getting color bleeding due to mipmaps and the dxt compression. inverting inside the material editor works via the oneMinus node which can come in handy depending on the decal to get even more variation.
http://content.screencast.com/users/divi/folders/Jing/media/534f9479-9276-4c35-b2a8-0e2220dacecf/2010-07-04_0013.png

[Tom Ellis]

Perfect Divi thanks a lot!