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Diffstat (limited to 'src/extras/shaders/gl3/metalroughuniform.frag')
-rw-r--r-- | src/extras/shaders/gl3/metalroughuniform.frag | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/src/extras/shaders/gl3/metalroughuniform.frag b/src/extras/shaders/gl3/metalroughuniform.frag new file mode 100644 index 000000000..f4bad0a00 --- /dev/null +++ b/src/extras/shaders/gl3/metalroughuniform.frag @@ -0,0 +1,371 @@ +/**************************************************************************** +** +** Copyright (C) 2017 Klaralvdalens Datakonsult AB (KDAB). +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the Qt3D module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** BSD License Usage +** Alternatively, you may use this file under the terms of the BSD license +** as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of The Qt Company Ltd nor the names of its +** contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#version 150 + +in vec2 texCoord; +in vec3 worldPosition; +in vec3 worldNormal; +in vec4 worldTangent; + +out vec4 fragColor; + +// Qt 3D built in uniforms +uniform vec3 eyePosition; // World space eye position +uniform float time; // Time in seconds + +// PBR Material maps +uniform vec4 baseColor; +uniform float metalness; +uniform float roughness; + +// Exposure correction +uniform float exposure = 0.0; +// Gamma correction +uniform float gamma = 2.2; + +#pragma include light.inc.frag + +int mipLevelCount(const in samplerCube cube) +{ + int baseSize = textureSize(cube, 0).x; + int nMips = int(log2(float(baseSize>0 ? baseSize : 1))) + 1; + return nMips; +} + +float remapRoughness(const in float roughness) +{ + // As per page 14 of + // http://www.frostbite.com/wp-content/uploads/2014/11/course_notes_moving_frostbite_to_pbr.pdf + // we remap the roughness to give a more perceptually linear response + // of "bluriness" as a function of the roughness specified by the user. + // r = roughness^2 + const float maxSpecPower = 999999.0; + const float minRoughness = sqrt(2.0 / (maxSpecPower + 2)); + return max(roughness * roughness, minRoughness); +} + +mat3 calcWorldSpaceToTangentSpaceMatrix(const in vec3 wNormal, const in vec4 wTangent) +{ + // Make the tangent truly orthogonal to the normal by using Gram-Schmidt. + // This allows to build the tangentMatrix below by simply transposing the + // tangent -> eyespace matrix (which would now be orthogonal) + vec3 wFixedTangent = normalize(wTangent.xyz - dot(wTangent.xyz, wNormal) * wNormal); + + // Calculate binormal vector. No "real" need to renormalize it, + // as built by crossing two normal vectors. + // To orient the binormal correctly, use the fourth coordinate of the tangent, + // which is +1 for a right hand system, and -1 for a left hand system. + vec3 wBinormal = cross(wNormal, wFixedTangent.xyz) * wTangent.w; + + // Construct matrix to transform from world space to tangent space + // This is the transpose of the tangentToWorld transformation matrix + mat3 tangentToWorldMatrix = mat3(wFixedTangent, wBinormal, wNormal); + mat3 worldToTangentMatrix = transpose(tangentToWorldMatrix); + return worldToTangentMatrix; +} + +float alphaToMipLevel(float alpha) +{ + float specPower = 2.0 / (alpha * alpha) - 2.0; + + // We use the mip level calculation from Lys' default power drop, which in + // turn is a slight modification of that used in Marmoset Toolbag. See + // https://docs.knaldtech.com/doku.php?id=specular_lys for details. + // For now we assume a max specular power of 999999 which gives + // maxGlossiness = 1. + const float k0 = 0.00098; + const float k1 = 0.9921; + float glossiness = (pow(2.0, -10.0 / sqrt(specPower)) - k0) / k1; + + // TODO: Optimize by doing this on CPU and set as + // uniform int envLight.specularMipLevels say (if present in shader). + // Lookup the number of mips in the specular envmap + int mipLevels = mipLevelCount(envLight.specular); + + // Offset of smallest miplevel we should use (corresponds to specular + // power of 1). I.e. in the 32x32 sized mip. + const float mipOffset = 5.0; + + // The final factor is really 1 - g / g_max but as mentioned above g_max + // is 1 by definition here so we can avoid the division. If we make the + // max specular power for the spec map configurable, this will need to + // be handled properly. + float mipLevel = (mipLevels - 1.0 - mipOffset) * (1.0 - glossiness); + return mipLevel; +} + +float normalDistribution(const in vec3 n, const in vec3 h, const in float alpha) +{ + // Blinn-Phong approximation - see + // http://graphicrants.blogspot.co.uk/2013/08/specular-brdf-reference.html + float specPower = 2.0 / (alpha * alpha) - 2.0; + return (specPower + 2.0) / (2.0 * 3.14159) * pow(max(dot(n, h), 0.0), specPower); +} + +vec3 fresnelFactor(const in vec3 color, const in float cosineFactor) +{ + // Calculate the Fresnel effect value + vec3 f = color; + vec3 F = f + (1.0 - f) * pow(1.0 - cosineFactor, 5.0); + return clamp(F, f, vec3(1.0)); +} + +float geometricModel(const in float lDotN, + const in float vDotN, + const in vec3 h) +{ + // Implicit geometric model (equal to denominator in specular model). + // This currently assumes that there is no attenuation by geometric shadowing or + // masking according to the microfacet theory. + return lDotN * vDotN; +} + +vec3 specularModel(const in vec3 F0, + const in float sDotH, + const in float sDotN, + const in float vDotN, + const in vec3 n, + const in vec3 h) +{ + // Clamp sDotN and vDotN to small positive value to prevent the + // denominator in the reflection equation going to infinity. Balance this + // by using the clamped values in the geometric factor function to + // avoid ugly seams in the specular lighting. + float sDotNPrime = max(sDotN, 0.001); + float vDotNPrime = max(vDotN, 0.001); + + vec3 F = fresnelFactor(F0, sDotH); + float G = geometricModel(sDotNPrime, vDotNPrime, h); + + vec3 cSpec = F * G / (4.0 * sDotNPrime * vDotNPrime); + return clamp(cSpec, vec3(0.0), vec3(1.0)); +} + +vec3 pbrModel(const in int lightIndex, + const in vec3 wPosition, + const in vec3 wNormal, + const in vec3 wView, + const in vec3 baseColor, + const in float metalness, + const in float alpha) +{ + // Calculate some useful quantities + vec3 n = wNormal; + vec3 s = vec3(0.0); + vec3 v = wView; + vec3 h = vec3(0.0); + + float vDotN = dot(v, n); + float sDotN = 0.0; + float sDotH = 0.0; + float att = 1.0; + + if (lights[lightIndex].type != TYPE_DIRECTIONAL) { + // Point and Spot lights + vec3 sUnnormalized = vec3(lights[lightIndex].position) - wPosition; + s = normalize(sUnnormalized); + + // Calculate the attenuation factor + sDotN = dot(s, n); + if (sDotN > 0.0) { + if (lights[lightIndex].constantAttenuation != 0.0 + || lights[lightIndex].linearAttenuation != 0.0 + || lights[lightIndex].quadraticAttenuation != 0.0) { + float dist = length(sUnnormalized); + att = 1.0 / (lights[lightIndex].constantAttenuation + + lights[lightIndex].linearAttenuation * dist + + lights[lightIndex].quadraticAttenuation * dist * dist); + } + + // The light direction is in world space already + if (lights[lightIndex].type == TYPE_SPOT) { + // Check if fragment is inside or outside of the spot light cone + if (degrees(acos(dot(-s, lights[lightIndex].direction))) > lights[lightIndex].cutOffAngle) + sDotN = 0.0; + } + } + } else { + // Directional lights + // The light direction is in world space already + s = normalize(-lights[lightIndex].direction); + sDotN = dot(s, n); + } + + h = normalize(s + v); + sDotH = dot(s, h); + + // Calculate diffuse component + vec3 diffuseColor = (1.0 - metalness) * baseColor * lights[lightIndex].color; + vec3 diffuse = diffuseColor * max(sDotN, 0.0) / 3.14159; + + // Calculate specular component + vec3 dielectricColor = vec3(0.04); + vec3 F0 = mix(dielectricColor, baseColor, metalness); + vec3 specularFactor = vec3(0.0); + if (sDotN > 0.0) { + specularFactor = specularModel(F0, sDotH, sDotN, vDotN, n, h); + specularFactor *= normalDistribution(n, h, alpha); + } + vec3 specularColor = lights[lightIndex].color; + vec3 specular = specularColor * specularFactor; + + // Blend between diffuse and specular to conserver energy + return att * lights[lightIndex].intensity * (specular + diffuse * (vec3(1.0) - specular)); +} + +vec3 pbrIblModel(const in vec3 wNormal, + const in vec3 wView, + const in vec3 baseColor, + const in float metalness, + const in float alpha) +{ + // Calculate reflection direction of view vector about surface normal + // vector in world space. This is used in the fragment shader to sample + // from the environment textures for a light source. This is equivalent + // to the l vector for punctual light sources. Armed with this, calculate + // the usual factors needed + vec3 n = wNormal; + vec3 l = reflect(-wView, n); + vec3 v = wView; + vec3 h = normalize(l + v); + float vDotN = dot(v, n); + float lDotN = dot(l, n); + float lDotH = dot(l, h); + + // Calculate diffuse component + vec3 diffuseColor = (1.0 - metalness) * baseColor; + vec3 diffuse = diffuseColor * texture(envLight.irradiance, l).rgb; + + // Calculate specular component + vec3 dielectricColor = vec3(0.04); + vec3 F0 = mix(dielectricColor, baseColor, metalness); + vec3 specularFactor = specularModel(F0, lDotH, lDotN, vDotN, n, h); + + // As per page 14 of + // http://www.frostbite.com/wp-content/uploads/2014/11/course_notes_moving_frostbite_to_pbr.pdf + // we remap the roughness to give a more perceptually linear response + // of "bluriness" as a function of the roughness specified by the user. + // r = roughness^2 + float lod = alphaToMipLevel(alpha); +//#define DEBUG_SPECULAR_LODS +#ifdef DEBUG_SPECULAR_LODS + if (lod > 7.0) + return vec3(1.0, 0.0, 0.0); + else if (lod > 6.0) + return vec3(1.0, 0.333, 0.0); + else if (lod > 5.0) + return vec3(1.0, 1.0, 0.0); + else if (lod > 4.0) + return vec3(0.666, 1.0, 0.0); + else if (lod > 3.0) + return vec3(0.0, 1.0, 0.666); + else if (lod > 2.0) + return vec3(0.0, 0.666, 1.0); + else if (lod > 1.0) + return vec3(0.0, 0.0, 1.0); + else if (lod > 0.0) + return vec3(1.0, 0.0, 1.0); +#endif + vec3 specularSkyColor = textureLod(envLight.specular, l, lod).rgb; + vec3 specular = specularSkyColor * specularFactor; + + // Blend between diffuse and specular to conserve energy + return specular + diffuse * (vec3(1.0) - specularFactor); +} + +vec3 toneMap(const in vec3 c) +{ + return c / (c + vec3(1.0)); +} + +vec3 gammaCorrect(const in vec3 color) +{ + return pow(color, vec3(1.0 / gamma)); +} + +void main() +{ + vec3 cLinear = vec3(0.0); + + // Remap roughness for a perceptually more linear correspondence + float alpha = remapRoughness(roughness); + + + vec3 wNormal = normalize(worldNormal); + vec3 worldView = normalize(eyePosition - worldPosition); + for (int i = 0; i < envLightCount; ++i) { + cLinear += pbrIblModel(wNormal, + worldView, + baseColor.rgb, + metalness, + alpha); + } + + for (int i = 0; i < lightCount; ++i) { + cLinear += pbrModel(i, + worldPosition, + wNormal, + worldView, + baseColor.rgb, + metalness, + alpha); + } + + // Apply exposure correction + cLinear *= pow(2.0, exposure); + + // Apply simple (Reinhard) tonemap transform to get into LDR range [0, 1] + vec3 cToneMapped = toneMap(cLinear); + + // Apply gamma correction prior to display + vec3 cGamma = gammaCorrect(cToneMapped); + fragColor = vec4(cGamma, 1.0); +} |