I have just discovered an alternative way to get emissive materials, the advantage of this way is that you can define the emissive part by the texture.
The way is simple, use an OP material, and make a black dds file
specify the operation like following:
map_op_1 = {
fileName = "black.dds",
magFilter = "LINEAR",
minFilter = "LINEAR_MIPMAP_LINEAR",
},
operation_1 = {
op = "MULTIPLICATION",
mode = "TEXCOORD",
scale = { 1.0, 1.0 },
opacity = -19.0
}
}
The key is the opacity parameter, once negative, the black part becomes emissive, and lower the value is, stronger the emissive become
So you make just copy the abeldo texture and make the emissive black and put it as the operation texture, then you get an emissive texture
If you want to know why, c.f util.fs applyOp function, and glsl documentation.