diff options
Diffstat (limited to 'source/blender/draw/engines/clay/shaders/ssao_groundtruth.glsl')
-rw-r--r-- | source/blender/draw/engines/clay/shaders/ssao_groundtruth.glsl | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/source/blender/draw/engines/clay/shaders/ssao_groundtruth.glsl b/source/blender/draw/engines/clay/shaders/ssao_groundtruth.glsl new file mode 100644 index 00000000000..9c203a4246c --- /dev/null +++ b/source/blender/draw/engines/clay/shaders/ssao_groundtruth.glsl @@ -0,0 +1,122 @@ +#define ssao_distance matcaps_param[mat_id].ssao_params_var.x +#define ssao_factor_cavity matcaps_param[mat_id].ssao_params_var.y +#define ssao_factor_edge matcaps_param[mat_id].ssao_params_var.z +#define ssao_attenuation matcaps_param[mat_id].ssao_params_var.w + +/* Based on Practical Realtime Strategies for Accurate Indirect Occlusion + * http://blog.selfshadow.com/publications/s2016-shading-course/activision/s2016_pbs_activision_occlusion.pdf + * http://blog.selfshadow.com/publications/s2016-shading-course/activision/s2016_pbs_activision_occlusion.pptx */ + +#define COSINE_WEIGHTING + +float integrate_arc(in float h1, in float h2, in float gamma, in float n_proj_len) +{ + float a = 0.0; +#ifdef COSINE_WEIGHTING + float cos_gamma = cos(gamma); + float sin_gamma_2 = 2.0 * sin(gamma); + a += -cos(2.0 * h1 - gamma) + cos_gamma + h1 * sin_gamma_2; + a += -cos(2.0 * h2 - gamma) + cos_gamma + h2 * sin_gamma_2; + a *= 0.25; /* 1/4 */ + a *= n_proj_len; +#else + /* Uniform weighting (slide 59) */ + a += 1 - cos(h1); + a += 1 - cos(h2); +#endif + return a; +} + +float get_max_horizon(in vec2 co, in vec3 x, in vec3 omega_o, in float h) +{ + if (co.x > 1.0 || co.x < 0.0 || co.y > 1.0 || co.y < 0.0) + return h; + + float depth = texture(depthtex, co).r; + + /* Background case */ + if (depth == 1.0) + return h; + + vec3 s = get_view_space_from_depth(co, depth); /* s View coordinate */ + vec3 omega_s = s - x; + float len = length(omega_s); + + if (len < ssao_distance) { + omega_s /= len; + h = max(h, dot(omega_s, omega_o)); + } + return h; +} + +void ssao_factors( + in float depth, in vec3 normal, in vec3 position, in vec2 screenco, + out float cavities, out float edges) +{ + /* Renaming */ + vec3 omega_o = -normalize(position); /* viewvec */ + vec2 x_ = screenco; /* x^ Screen coordinate */ + vec3 x = position; /* x view space coordinate */ + +#ifdef SPATIAL_DENOISE + float noise_dir = (1.0 / 16.0) * float(((int(gl_FragCoord.x + gl_FragCoord.y) & 0x3) << 2) + (int(gl_FragCoord.x) & 0x3)); + float noise_offset = (1.0 / 4.0) * float(int(gl_FragCoord.y - gl_FragCoord.x) & 0x3); +#else + float noise_dir = (1.0 / 16.0) * float(((int(gl_FragCoord.x + gl_FragCoord.y) & 0x3) << 2) + (int(gl_FragCoord.x) & 0x3)); + float noise_offset = (0.5 / 16.0) + (1.0 / 16.0) * float(((int(gl_FragCoord.x - gl_FragCoord.y) & 0x3) << 2) + (int(gl_FragCoord.x) & 0x3)); +#endif + + const float phi_step = 16.0; + const float theta_step = 16.0; + const float m_pi = 3.14159265358979323846; + vec2 pixel_ratio = vec2(screenres.y / screenres.x, 1.0); + vec2 pixel_size = vec2(1.0) / screenres.xy; + float min_stride = length(pixel_size); + float homcco = WinMatrix[2][3] * position.z + WinMatrix[3][3]; + float n = max(min_stride * theta_step, ssao_distance / homcco); /* Search distance */ + + /* Integral over PI */ + float A = 0.0; + for (float i = 0.0; i < phi_step; i++) { + float phi = m_pi * ((noise_dir + i) / phi_step); + + vec2 t_phi = vec2(cos(phi), sin(phi)); /* Screen space direction */ + + /* Search maximum horizon angles Theta1 and Theta2 */ + float theta1 = -1.0, theta2 = -1.0; /* init at cos(pi) */ + for (float j = 0.0; j < theta_step; j++) { + vec2 s_ = t_phi * pixel_ratio * n * ((j + noise_offset)/ theta_step); /* s^ Screen coordinate */ + vec2 co; + + co = x_ + s_; + theta1 = get_max_horizon(co, x, omega_o, theta1); + + co = x_ - s_; + theta2 = get_max_horizon(co, x, omega_o, theta2); + } + + /* (Slide 54) */ + theta1 = -acos(theta1); + theta2 = acos(theta2); + + /* Projecting Normal to Plane P defined by t_phi and omega_o */ + vec3 h = normalize(cross(vec3(t_phi, 0.0), omega_o)); /* Normal vector to Integration plane */ + vec3 t = cross(h, omega_o); /* Normal vector to plane */ + vec3 n_proj = normal - h * dot(normal, h); + float n_proj_len = length(n_proj); + vec3 n_proj_norm = normalize(n_proj); + + /* Clamping thetas (slide 58) */ + float gamma = sign(dot(n_proj_norm, t)) * acos(dot(normal, omega_o)); /* Angle between view vec and normal */ + theta1 = gamma + max(theta1 - gamma, -m_pi * 0.5); + theta2 = gamma + min(theta2 - gamma, m_pi * 0.5); + + /* Solving inner integral */ + A += integrate_arc(theta1, theta2, gamma, n_proj_len); + } + + A /= phi_step; + + cavities = 1.0 - A; + edges = 0.0; +} |