From efbd8eb75e046e8d3ac4781b604e28bb72f4e358 Mon Sep 17 00:00:00 2001 From: QwertyChouskie Date: Mon, 30 Aug 2021 01:34:02 -0700 Subject: [PATCH] Screen-space refection: many fixes + optimization (#4575) --- data/shaders/IBL.frag | 105 ++++++++++++++++++++---------------------- 1 file changed, 51 insertions(+), 54 deletions(-) diff --git a/data/shaders/IBL.frag b/data/shaders/IBL.frag index 99b29a4e5..8f8202e68 100644 --- a/data/shaders/IBL.frag +++ b/data/shaders/IBL.frag @@ -16,23 +16,15 @@ out vec4 Spec; #stk_include "utils/SpecularIBL.frag" -vec3 getXcYcZc(int x, int y, float zC) -{ - // We use perspective symetric projection matrix hence P(0,2) = P(1, 2) = 0 - float xC= (2. * (float(x)) / u_screen.x - 1.) * zC / u_projection_matrix[0][0]; - float yC= (2. * (float(y)) / u_screen.y - 1.) * zC / u_projection_matrix[1][1]; - return vec3(xC, yC, zC); -} - float makeLinear(float f, float n, float z) { return (2.0f * n) / (f + n - z * (f - n)); } -vec3 CalcViewPositionFromDepth(in vec2 TexCoord, in sampler2D DepthMap) +vec3 CalcViewPositionFromDepth(in vec2 TexCoord) { // Combine UV & depth into XY & Z (NDC) - float z = makeLinear(1000.0, 1.0, textureLod(DepthMap, TexCoord, 0.).x); + float z = makeLinear(1000.0, 1.0, textureLod(dtex, TexCoord, 0.).x); vec3 rawPosition = vec3(TexCoord, z); // Convert from (0, 1) range to (-1, 1) @@ -45,14 +37,18 @@ vec3 CalcViewPositionFromDepth(in vec2 TexCoord, in sampler2D DepthMap) return ViewPosition.xyz / ViewPosition.w; } -float GetVignette(float factor) +// Fade out edges of screen buffer tex +// 1 means full render tex, 0 means full IBL tex +float GetEdgeFade(vec2 coords) { - vec2 inside = (gl_FragCoord.xy / u_screen) - 0.5; - float vignette = 1. - dot(inside, inside) * 5.0; - return clamp(pow(vignette, factor), 0., 1.0); + float gradL = smoothstep(0.0, 0.4, coords.x); + float gradR = 1.0 - smoothstep(0.6, 1.0, coords.x); + float gradT = smoothstep(0.0, 0.4, coords.y); + float gradB = 1.0 - smoothstep(0.6, 1.0, coords.y); + return min(min(gradL, gradR), min(gradT, gradB)); } -vec3 RayCast(vec3 dir, inout vec3 hitCoord, out float dDepth, in sampler2D DepthMap, in vec3 fallback, float spread) +vec2 RayCast(vec3 dir, inout vec3 hitCoord, out float dDepth) { dir *= 0.25f; @@ -63,39 +59,24 @@ vec3 RayCast(vec3 dir, inout vec3 hitCoord, out float dDepth, in sampler2D Depth projectedCoord.xy /= projectedCoord.w; projectedCoord.xy = projectedCoord.xy * 0.5 + 0.5; - float depth = CalcViewPositionFromDepth(projectedCoord.xy, DepthMap).z; + float depth = CalcViewPositionFromDepth(projectedCoord.xy).z; dDepth = hitCoord.z - depth; - if(dDepth < 0.0) + if (dDepth < 0.0) { - // Texture wrapping to extand artifcially the range of the lookup texture - // FIXME can be improved to lessen the distortion - projectedCoord.y = min(.99, projectedCoord.y); - projectedCoord.x = min(.99, projectedCoord.x); - projectedCoord.x = max(.01, projectedCoord.x); - - // We want only reflection on nearly horizontal surfaces - float cutout = dot(dir, vec3(0., 0., -1.)); - - if ((projectedCoord.x > 0.0 && projectedCoord.x < 1.0) - && (projectedCoord.y > 0.0 && projectedCoord.y < 1.0) - && (cutout > 10.0) - ) + if (projectedCoord.x > 0.0 && projectedCoord.x < 1.0 && + projectedCoord.y > 0.0 && projectedCoord.y < 1.0) { - // FIXME We need to generate mipmap to take into account the gloss map - vec3 finalColor = textureLod(albedo, projectedCoord.xy, spread).rgb; - //return finalColor; - return mix(fallback, finalColor, GetVignette(4.)); - + return projectedCoord.xy; } else { - return fallback; + return vec2(0.f); } } } - return fallback; + return vec2(0.f); } // Main =================================================================== @@ -119,30 +100,46 @@ void main(void) #else // :::::::: Compute Space Screen Reflection :::::::::::::::::::::::::::::::::::: - float lineardepth = textureLod(dtex, uv, 0.).x; + // Output color + vec3 outColor; // Fallback (if the ray can't find an intersection we display the sky) vec3 fallback = .25 * SpecularIBL(normal, eyedir, specval); - float View_Depth = makeLinear(1000.0, 1.0, lineardepth); - vec3 ScreenPos = xpos.xyz; - vec4 View_Pos = u_inverse_projection_matrix * vec4(ScreenPos, 1.0f); - View_Pos /= View_Pos.w; + // Only calculate reflections if the reflectivity value is high enough, + // otherwise just use specular IBL + if (specval > 0.5) + { + vec3 View_Pos = CalcViewPositionFromDepth(uv); - // Reflection vector - vec3 reflected = normalize(reflect(eyedir, normal)); + // Reflection vector + vec3 reflected = normalize(reflect(eyedir, normal)); - // Ray cast - vec3 hitPos = View_Pos.xyz; - float dDepth; - float minRayStep = 100.0f; + // Ray cast + vec3 hitPos = View_Pos.xyz; + float dDepth; + float minRayStep = 50.0f; + + vec2 coords = RayCast(reflected * max(minRayStep, -View_Pos.z), + hitPos, dDepth); + + if (coords.x == 0.0 && coords.y == 0.0) { + outColor = fallback; + } else { + // FIXME We need to generate mipmap to take into account the gloss map + outColor = textureLod(albedo, coords, 0.f).rgb; + outColor = mix(fallback, outColor, GetEdgeFade(coords)); + // TODO temporary measure the lack of mipmapping for RTT albedo + // Implement it in proper way + // Use (specval - 0.5) * 2.0 to bring specval from 0.5-1.0 range to 0.0-1.0 range + outColor = mix(fallback, outColor, (specval - 0.5) * 2.0); + } + } + else + { + outColor = fallback; + } - vec3 outColor = RayCast(reflected * max(minRayStep, -xpos.z), - hitPos, dDepth, dtex, fallback, 0.0); - - // TODO temporary measure the lack of mipmaping for RTT albedo - // Implement it in proper way - outColor = mix(fallback, outColor, specval); Spec = vec4(outColor.rgb, 1.0); #endif