RGB shader with decals

[tjheldna]

Hi All,

 

I'm trying my hand at modifying the diffuse_normal shader to do a particular task.

 

Basicly I want to texture cars using rgb values with a decal texture overlay. Doing this I can easily change the color of the cars paintwork using rgb values but keep things like lights, damage, interior the same.

 

 

This does work but one thing I can't do is get a nice alpha fade off, blended by the alpha value on the texture with the rgb value.

 

float textureAlpha = texture(texture0,ex_texcoords0).a;

if(textureAlpha > 0.0)
{
outcolor = texture(texture0,ex_texcoords0);
}
else
{
outcolor = (ex_color * (1.0 - texture(texture0,ex_texcoords0).a));
}

 

 

 

If I change the 0.0 value I get various results but always a hard line around the decals where I'm trying to blend with the texture alpha.

 

Any insight into this would be great!

 

Thanks

[macklebee]

Essentially you are just doing what the alphatest shader performs - ignore anything below (or above) a fixed alpha limit which will always give a hard line if you have varying alpha in your texture. In LE2, we had the alphablend shader but this only worked when the object was drawn in the transparency world. I would try to combine the color with the texture via a mix() without regards to an alpha limit. It would probably be easier for others to test if you supplied an example object, the full shader, and an example decal texture.

[tjheldna]

Thanks macklebee, I'll try mix. I'll also put something together for testing.

 

Just wondering where can a find a good list of functions available to me for shaders in LE?

[macklebee]

Just wondering where can a find a good list of functions available to me for shaders in LE?

 

This is the official reference card: https://www.opengl.org/sdk/docs/reference_card/opengl44-quick-reference-card.pdf

 

Edit- theres a new one for 4.5 but LE projects appear to be still using 4.4 since 4.5 was just released a month ago (also the built-in functions essentially havent changed much in years).

 

Also, in the previous post i suggested to do a mix without regards to the alpha - actually i would try to use the texture's alpha as the interpolation step value in the mix() function to determine if the color or the texture would be more prevalent.

[tjheldna]

Thanks Macklebee for pointing me in the right direction. I got it working in one line.

 

//Decals

outcolor = mix(ex_color, texture(texture0, ex_texcoords0), texture(texture0,ex_texcoords0).a)

 

 

 

Summer Games Tournament Truck01 thanks you!