[SOLVED] Blend math used in editor

kenc · October 9, 2019, 1:58pm

Hi All

First posting to Playcanvas. I’m not a playcanvas user but I am working with a colleague who is.

I am trying to emulate the blend between a RGB value and a texture map in the editor. I am trying to emulate it in 3DSMAX, to create the same look as it looks in the playcanvas editor.

TIA

will · October 9, 2019, 2:04pm

The code is here:

github.com

playcanvas/engine/blob/master/src/graphics/program-lib/chunks/diffuse.frag

#ifdef MAPCOLOR
uniform vec3 material_diffuse;
#endif

#ifdef MAPTEXTURE
uniform sampler2D texture_diffuseMap;
#endif

void getAlbedo() {
    dAlbedo = vec3(1.0);

    #ifdef MAPCOLOR
        dAlbedo *= material_diffuse.rgb;
    #endif

    #ifdef MAPTEXTURE
        dAlbedo *= texture2DSRGB(texture_diffuseMap, $UV).$CH;
    #endif

    #ifdef MAPVERTEX

This file has been truncated. show original

So, in your case, you have MAPCOLOR and MAPTEXTURE defined. So the math is:

    albedoColor = tintColor * diffuseMapColor

kenc · October 9, 2019, 2:09pm

Thanks Will

So this is a multiplication of the tint on top of the texture? If so, could I use the Photoshop multiply algorithm?

will · October 9, 2019, 2:10pm

Sounds like it should do the same.

kenc · October 9, 2019, 3:17pm

Thanks Will

I’ll give that a try. Now to find the Photoshop equation. Any ideas?

Leonidas · October 9, 2019, 3:20pm

Hi @kenc,

This will come in handy: https://github.com/jamieowen/glsl-blend

It includes a collection of .glsl files containing most of the Photoshop blending modes.

kenc · October 9, 2019, 3:28pm

Thanks Leonidas, I will check it out. I will also report back with my results, but it may not be till next week.

Thanks again Will and Leonidas.