v4k-git-backup/engine/art/shaderlib/surface.glsl

202 lines
6.2 KiB
GLSL

#include "sh_lighting.glsl"
#include "rimlight.glsl"
#include "light.glsl"
struct surface_t {
vec3 normal;
vec4 albedo;
vec4 fragcolor;
vec3 light_direct;
vec3 light_indirect;
vec3 emissive;
float roughness;
float metallic;
float ao;
float alpha;
};
surface_t surface() {
surface_t s;
s.normal = normalize(v_normal_ws);
s.light_direct = vec3(0.0, 0.0, 0.0);
s.light_indirect = vec3(1.0, 1.0, 1.0);
s.albedo = vec4(0.5, 0.5, 0.5, 1.0);
s.emissive = vec3(0.0, 0.0, 0.0);
s.roughness = 1.0;
s.metallic = 0.0;
s.ao = 1.0;
s.alpha = 1.0;
// SH lighting
if (!u_texlit) {
vec3 result = sh_lighting(s.normal);
if( (result.x*result.x+result.y*result.y+result.z*result.z) > 0.0 ) s.light_indirect = result;
}
#ifdef SHADING_PHONG
material_t dummy_mat;
s.light_direct = lighting(dummy_mat);
#endif
#ifdef SHADING_VERTEXLIT
s.light_direct = v_vertcolor;
#endif
#ifdef SHADING_PBR
vec4 baseColor_alpha;
if ( map_albedo.has_tex )
baseColor_alpha = sample_colormap( map_albedo, v_texcoord );
else
baseColor_alpha = sample_colormap( map_diffuse, v_texcoord );
s.albedo = baseColor_alpha;
if( map_metallic.has_tex && map_roughness.has_tex ) {
s.metallic = sample_colormap( map_metallic, v_texcoord ).x;
s.roughness = sample_colormap( map_roughness, v_texcoord ).x;
}
else if( map_roughness.has_tex ) {
s.metallic = sample_colormap( map_roughness, v_texcoord ).b;
s.roughness = sample_colormap( map_roughness, v_texcoord ).g;
}
if ( map_ao.has_tex )
s.ao = sample_colormap( map_ao, v_texcoord ).x;
else if ( map_ambient.has_tex )
s.ao = sample_colormap( map_ambient, v_texcoord ).x;
s.emissive = sample_colormap( map_emissive, v_texcoord ).rgb;
vec3 normalmap = texture( map_normals_tex, v_texcoord ).xyz * vec3(2.0) - vec3(1.0);
float normalmap_mip = textureQueryLod( map_normals_tex, v_texcoord ).x;
float normalmap_length = length(normalmap);
normalmap /= normalmap_length;
s.normal = v_normal_ws;
if ( map_normals.has_tex )
{
// Mikkelsen's tangent space normal map decoding. See http://mikktspace.com/ for rationale.
vec3 bi = cross( v_normal_ws, v_tangent );
vec3 nmap = normalmap.xyz;
s.normal = nmap.x * v_tangent + nmap.y * bi + nmap.z * v_normal_ws;
}
s.normal = normalize( s.normal );
if (USE_NORMAL_VARIATION_TO_ROUGHNESS)
{
// Try to reduce specular aliasing by increasing roughness when minified normal maps have high variation.
float variation = 1. - pow( normalmap_length, 8. );
float minification = clamp( normalmap_mip - 2., 0., 1. );
s.roughness = mix( s.roughness, 1.0, variation * minification );
}
vec3 N = s.normal;
vec3 V = normalize( v_to_camera );
vec3 Lo = vec3(0.);
vec3 F0 = vec3(0.04);
F0 = mix( F0, s.albedo.rgb, s.metallic );
bool use_ibl = has_tex_skysphere;
material_t pbr_mat;
pbr_mat.albedo = s.albedo.rgb;
pbr_mat.normal = N;
pbr_mat.F0 = F0;
pbr_mat.roughness = s.roughness;
pbr_mat.metallic = s.metallic;
pbr_mat.alpha = s.alpha;
// Lo += lighting(pbr_mat);
s.light_indirect = sample_colormap( map_ambient, v_texcoord ).xyz;
vec3 diffuse_ambient;
vec3 specular_ambient;
if ( use_ibl )
{
// Image based lighting.
// Based on https://learnopengl.com/PBR/IBL/Diffuse-irradiance
vec3 irradiance = vec3(0.);
if ( USE_BRUTEFORCE_IRRADIANCE )
{
irradiance = sample_irradiance_slow( N, v_tangent );
}
else
{
irradiance = sample_irradiance_fast( N, v_tangent );
}
// Compute the Fresnel term for a perfect mirror reflection with L = R.
// In this case the halfway vector H = N.
//
// We use a modified Fresnel function that dampens specular reflections of very
// rough surfaces to avoid too bright pixels at grazing angles.
vec3 F = fresnel_schlick_roughness( N, V, F0, s.roughness );
vec3 kS = F;
// Subtract the amount of reflected light (specular) to get the energy left for
// absorbed (diffuse) light.
vec3 kD = vec3(1.) - kS;
// Metallic surfaces have only a specular reflection.
kD *= 1.0 - s.metallic;
// Premultiplied alpha applied to the diffuse component only
kD *= s.alpha;
// Modulate the incoming lighting with the diffuse color: some wavelengths get absorbed.
diffuse_ambient = irradiance * s.albedo.rgb;
// Ambient light also has a specular part.
specular_ambient = specular_ibl( V, N, s.roughness, F );
// Ambient occlusion tells us the fraction of sky light that reaches this point.
if (USE_SPECULAR_AO_ATTENUATION)
{
s.light_indirect += s.ao * (kD * diffuse_ambient + specular_ambient);
}
else
{
// We don't attenuate specular_ambient ambient here with AO which might cause flickering in dark cavities.
s.light_indirect += s.ao * (kD * diffuse_ambient) + specular_ambient;
}
}
#else
if(u_matcaps) {
vec2 muv = vec2(view * vec4(v_normal_ws, 0))*0.5+vec2(0.5,0.5); // normal (model space) to view space
s.albedo = texture(u_texture2d, vec2(muv.x, 1.0-muv.y));
} else if(u_textured) {
s.albedo = texture(u_texture2d, v_texcoord);
} else {
s.albedo = u_diffuse;
}
if (u_texlit) {
vec4 litsample = texture(u_lightmap, v_texcoord);
if (u_texmod) {
s.albedo *= litsample;
} else {
s.albedo += litsample;
}
s.albedo.rgb += sh_lighting(s.normal);
}
#endif
s.albedo *= v_color;
s.fragcolor = s.albedo;
s.fragcolor.rgb *= s.light_direct + s.light_indirect;
s.fragcolor.rgb += s.emissive;
s.fragcolor *= shadowing();
s.fragcolor.rgb += get_rimlight();
return s;
}