48 lines
1.1 KiB
GLSL
48 lines
1.1 KiB
GLSL
|
|
in vec3 coords;
|
|
out vec4 fragColor;
|
|
|
|
uniform vec3 active_color;
|
|
uniform float step_size;
|
|
uniform float density_scale;
|
|
|
|
uniform sampler3D soot_texture;
|
|
uniform sampler3D shadow_texture;
|
|
|
|
#ifdef USE_COBA
|
|
uniform sampler1D transfer_texture;
|
|
uniform sampler3D color_band_texture;
|
|
#endif
|
|
|
|
void main()
|
|
{
|
|
/* compute color and density from volume texture */
|
|
vec4 soot = texture(soot_texture, coords);
|
|
|
|
#ifndef USE_COBA
|
|
vec3 soot_color;
|
|
if (soot.a != 0) {
|
|
soot_color = active_color * soot.rgb / soot.a;
|
|
}
|
|
else {
|
|
soot_color = vec3(0);
|
|
}
|
|
float soot_density = density_scale * soot.a;
|
|
|
|
/* compute transmittance and alpha */
|
|
float soot_transmittance = pow(2.71828182846, -soot_density * step_size);
|
|
float soot_alpha = 1.0 - soot_transmittance;
|
|
|
|
/* shade */
|
|
float shadow = texture(shadow_texture, coords).r;
|
|
soot_color *= soot_transmittance * shadow;
|
|
|
|
/* premultiply alpha */
|
|
fragColor = vec4(soot_alpha * soot_color, soot_alpha);
|
|
#else
|
|
float color_band = texture(color_band_texture, coords).r;
|
|
vec4 transfer_function = texture(transfer_texture, color_band);
|
|
fragColor = transfer_function * density_scale;
|
|
#endif
|
|
}
|