Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Update PBR lighting #6430

Merged
merged 12 commits into from
Apr 27, 2018
Merged

Update PBR lighting #6430

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
12 commits
Select commit Hold shift + click to select a range
d64ae0a
Convert to and from sRGB, so PBR calc happens in linear space.
emackey Apr 5, 2018
e1746ba
Tweak procedural IBL gradients and Sun light strength.
emackey Apr 5, 2018
7d66400
CHANGES.md
emackey Apr 5, 2018
21d2e85
Tweak high-roughness lighting to be friendlier to non-PBR models.
emackey Apr 9, 2018
0270f59
Merge remote-tracking branch 'origin/master' into pbr-lighting
emackey Apr 16, 2018
2156798
Merge remote-tracking branch 'origin/master' into pbr-lighting
emackey Apr 18, 2018
34fafb5
Clamp horizonDotNadir calculation to effectively push any subsurface …
abwood Apr 19, 2018
15a6b1c
Merge pull request #6467 from abwood/pbr-lighting
emackey Apr 19, 2018
f513600
Rebalance some gradients to not look washed out.
emackey Apr 26, 2018
d87f278
Merge remote-tracking branch 'origin/master' into pbr-lighting
emackey Apr 26, 2018
8a381c5
Merge remote-tracking branch 'origin/master' into pbr-lighting
emackey Apr 27, 2018
b86b871
Tweak linear/sRGB placement, add missing term from diffuseColor.
emackey Apr 27, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions CHANGES.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@ Change Log
* Fixed bugs in `TimeIntervalCollection.removeInterval`. [#6418](https://github.com/AnalyticalGraphicsInc/cesium/pull/6418).
* Fixed glTF support to handle meshes with and without tangent vectors, and with/without morph targets, sharing one material. [#6421](https://github.com/AnalyticalGraphicsInc/cesium/pull/6421)
* Fixed glTF support to handle skinned meshes when no skin is supplied. [#6061](https://github.com/AnalyticalGraphicsInc/cesium/issues/6061)
* Updated glTF 2.0 PBR shader to have brighter lighting. [#6430](https://github.com/AnalyticalGraphicsInc/cesium/pull/6430)
* Allow loadWithXhr to work with string URLs in a web worker.
* Updated to Draco 1.3.0 and implemented faster loading of Draco compressed glTF assets in browsers that support Web Assembly. [#6420](https://github.com/AnalyticalGraphicsInc/cesium/pull/6420)
* `GroundPrimitive`s and `ClassificationPrimitive`s will become ready when `show` is `false`. [#6428](https://github.com/AnalyticalGraphicsInc/cesium/pull/6428)
Expand Down
60 changes: 42 additions & 18 deletions Source/ThirdParty/GltfPipeline/processPbrMetallicRoughness.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -389,9 +389,9 @@ define([
// Fragment shader lighting
fragmentShader += 'const float M_PI = 3.141592653589793;\n';

fragmentShader += 'vec3 lambertianDiffuse(vec3 baseColor) \n' +
fragmentShader += 'vec3 lambertianDiffuse(vec3 diffuseColor) \n' +
'{\n' +
' return baseColor / M_PI;\n' +
' return diffuseColor / M_PI;\n' +
'}\n\n';

fragmentShader += 'vec3 fresnelSchlick2(vec3 f0, vec3 f90, float VdotH) \n' +
Expand Down Expand Up @@ -422,6 +422,22 @@ define([
' return roughnessSquared / (M_PI * f * f);\n' +
'}\n\n';

fragmentShader += 'vec3 SRGBtoLINEAR3(vec3 srgbIn) \n' +
'{\n' +
' return pow(srgbIn, vec3(2.2));\n' +
'}\n\n';

fragmentShader += 'vec4 SRGBtoLINEAR4(vec4 srgbIn) \n' +
'{\n' +
' vec3 linearOut = pow(srgbIn.rgb, vec3(2.2));\n' +
' return vec4(linearOut, srgbIn.a);\n' +
'}\n\n';

fragmentShader += 'vec3 LINEARtoSRGB(vec3 linearIn) \n' +
'{\n' +
' return pow(linearIn, vec3(1.0/2.2));\n' +
'}\n\n';

fragmentShader += 'void main(void) \n{\n';

// Add normal mapping to fragment shader
Expand Down Expand Up @@ -470,7 +486,7 @@ define([

// Add base color to fragment shader
if (defined(parameterValues.baseColorTexture)) {
fragmentShader += ' vec4 baseColorWithAlpha = texture2D(u_baseColorTexture, ' + v_texcoord + ');\n';
fragmentShader += ' vec4 baseColorWithAlpha = SRGBtoLINEAR4(texture2D(u_baseColorTexture, ' + v_texcoord + '));\n';
if (defined(parameterValues.baseColorFactor)) {
fragmentShader += ' baseColorWithAlpha *= u_baseColorFactor;\n';
}
Expand Down Expand Up @@ -513,10 +529,12 @@ define([
fragmentShader += ' vec3 v = -normalize(v_positionEC);\n';

// Generate fragment shader's lighting block
fragmentShader += ' vec3 lightColor = vec3(1.0, 1.0, 1.0);\n';
if (optimizeForCesium) {
// The Sun is brighter than your average light source, and has a yellowish tint balanced by the Earth's ambient blue.
fragmentShader += ' vec3 lightColor = vec3(1.5, 1.4, 1.2);\n';
fragmentShader += ' vec3 l = normalize(czm_sunDirectionEC);\n';
} else {
fragmentShader += ' vec3 lightColor = vec3(1.0, 1.0, 1.0);\n';
fragmentShader += ' vec3 l = vec3(0.0, 0.0, 1.0);\n';
}
fragmentShader += ' vec3 h = normalize(v + l);\n';
Expand All @@ -525,7 +543,7 @@ define([
// Figure out if the reflection vector hits the ellipsoid
fragmentShader += ' czm_ellipsoid ellipsoid = czm_getWgs84EllipsoidEC();\n';
fragmentShader += ' float vertexRadius = length(v_positionWC);\n';
fragmentShader += ' float horizonDotNadir = 1.0 - ellipsoid.radii.x / vertexRadius;\n';
fragmentShader += ' float horizonDotNadir = 1.0 - min(1.0, ellipsoid.radii.x / vertexRadius);\n';
fragmentShader += ' float reflectionDotNadir = dot(r, normalize(v_positionWC));\n';
// Flipping the X vector is a cheap way to get the inverse of czm_temeToPseudoFixed, since that's a rotation about Z.
fragmentShader += ' r.x = -r.x;\n';
Expand All @@ -542,7 +560,7 @@ define([

fragmentShader += ' vec3 f0 = vec3(0.04);\n';
fragmentShader += ' float alpha = roughness * roughness;\n';
fragmentShader += ' vec3 diffuseColor = baseColor * (1.0 - metalness);\n';
fragmentShader += ' vec3 diffuseColor = baseColor * (1.0 - metalness) * (1.0 - f0);\n';
fragmentShader += ' vec3 specularColor = mix(f0, baseColor, metalness);\n';
fragmentShader += ' float reflectance = max(max(specularColor.r, specularColor.g), specularColor.b);\n';
fragmentShader += ' vec3 r90 = vec3(clamp(reflectance * 25.0, 0.0, 1.0));\n';
Expand All @@ -552,44 +570,49 @@ define([
fragmentShader += ' float G = smithVisibilityGGX(alpha, NdotL, NdotV);\n';
fragmentShader += ' float D = GGX(alpha, NdotH);\n';

fragmentShader += ' vec3 diffuseContribution = (1.0 - F) * lambertianDiffuse(baseColor);\n';
fragmentShader += ' vec3 diffuseContribution = (1.0 - F) * lambertianDiffuse(diffuseColor);\n';
fragmentShader += ' vec3 specularContribution = F * G * D / (4.0 * NdotL * NdotV);\n';
fragmentShader += ' vec3 color = NdotL * lightColor * (diffuseContribution + specularContribution);\n';

if (optimizeForCesium) {
fragmentShader += ' float inverseRoughness = 1.0 - roughness;\n';
fragmentShader += ' float inverseRoughness = 1.04 - roughness;\n';
fragmentShader += ' inverseRoughness *= inverseRoughness;\n';
fragmentShader += ' vec3 sceneSkyBox = textureCube(czm_environmentMap, r).rgb * inverseRoughness;\n';

fragmentShader += ' float atmosphereHeight = 0.05;\n';
fragmentShader += ' float blendRegionSize = 0.1 * ((1.0 - inverseRoughness) * 8.0 + 1.1 - horizonDotNadir);\n';
fragmentShader += ' float farAboveHorizon = clamp(horizonDotNadir - blendRegionSize * 0.5, 1.0e-10 - blendRegionSize, 0.99999);\n';
fragmentShader += ' float blendRegionOffset = roughness * -1.0;\n';
fragmentShader += ' float farAboveHorizon = clamp(horizonDotNadir - blendRegionSize * 0.5 + blendRegionOffset, 1.0e-10 - blendRegionSize, 0.99999);\n';
fragmentShader += ' float aroundHorizon = clamp(horizonDotNadir + blendRegionSize * 0.5, 1.0e-10 - blendRegionSize, 0.99999);\n';
fragmentShader += ' float farBelowHorizon = clamp(horizonDotNadir + blendRegionSize * 1.5, 1.0e-10 - blendRegionSize, 0.99999);\n';
fragmentShader += ' float smoothstepHeight = smoothstep(0.0, atmosphereHeight, horizonDotNadir);\n';
fragmentShader += ' float lightScale = smoothstepHeight * 1.5 + 1.0;\n';

fragmentShader += ' vec3 diffuseIrradiance = mix(vec3(0.5), vec3(0.05), smoothstepHeight);\n';
fragmentShader += ' vec3 belowHorizonColor = mix(vec3(0.1, 0.2, 0.4), vec3(0.2, 0.5, 0.7), smoothstepHeight);\n';
fragmentShader += ' vec3 belowHorizonColor = mix(vec3(0.1, 0.15, 0.25), vec3(0.4, 0.7, 0.9), smoothstepHeight);\n';
fragmentShader += ' vec3 nadirColor = belowHorizonColor * 0.5;\n';
fragmentShader += ' vec3 aboveHorizonColor = vec3(0.8, 0.9, 0.95);\n';
fragmentShader += ' vec3 blueSkyColor = mix(vec3(0.09, 0.13, 0.24), aboveHorizonColor, reflectionDotNadir * inverseRoughness * 0.5 + 0.5);\n';
fragmentShader += ' vec3 aboveHorizonColor = mix(vec3(0.9, 1.0, 1.2), belowHorizonColor, roughness * 0.5);\n';
fragmentShader += ' vec3 blueSkyColor = mix(vec3(0.18, 0.26, 0.48), aboveHorizonColor, reflectionDotNadir * inverseRoughness * 0.5 + 0.75);\n';
fragmentShader += ' vec3 zenithColor = mix(blueSkyColor, sceneSkyBox, smoothstepHeight);\n';

fragmentShader += ' vec3 specularIrradiance = mix(zenithColor, aboveHorizonColor, smoothstep(farAboveHorizon, aroundHorizon, reflectionDotNadir) * inverseRoughness);\n';
fragmentShader += ' vec3 blueSkyDiffuseColor = vec3(0.7, 0.85, 0.9);\n';
fragmentShader += ' float diffuseIrradianceFromEarth = (1.0 - horizonDotNadir) * (reflectionDotNadir * 0.25 + 0.75) * smoothstepHeight;\n';
fragmentShader += ' float diffuseIrradianceFromSky = (1.0 - smoothstepHeight) * (1.0 - (reflectionDotNadir * 0.25 + 0.25));\n';
fragmentShader += ' vec3 diffuseIrradiance = blueSkyDiffuseColor * clamp(diffuseIrradianceFromEarth + diffuseIrradianceFromSky, 0.0, 1.0);\n';

fragmentShader += ' float notDistantRough = (1.0 - horizonDotNadir * roughness * 0.8);\n';
fragmentShader += ' vec3 specularIrradiance = mix(zenithColor, aboveHorizonColor, smoothstep(farAboveHorizon, aroundHorizon, reflectionDotNadir) * notDistantRough);\n';
fragmentShader += ' specularIrradiance = mix(specularIrradiance, belowHorizonColor, smoothstep(aroundHorizon, farBelowHorizon, reflectionDotNadir) * inverseRoughness);\n';
fragmentShader += ' specularIrradiance = mix(specularIrradiance, nadirColor, smoothstep(farBelowHorizon, 1.0, reflectionDotNadir) * inverseRoughness);\n';

fragmentShader += ' vec2 brdfLut = texture2D(czm_brdfLut, vec2(NdotV, 1.0 - roughness)).rg;\n';
fragmentShader += ' vec3 IBLColor = (diffuseIrradiance * diffuseColor) + (specularIrradiance * (specularColor * brdfLut.x + brdfLut.y));\n';
fragmentShader += ' color = color * lightScale + IBLColor;\n';
fragmentShader += ' vec3 IBLColor = (diffuseIrradiance * diffuseColor) + (specularIrradiance * SRGBtoLINEAR3(specularColor * brdfLut.x + brdfLut.y));\n';
fragmentShader += ' color += IBLColor;\n';
}

if (defined(parameterValues.occlusionTexture)) {
fragmentShader += ' color *= texture2D(u_occlusionTexture, ' + v_texcoord + ').r;\n';
}
if (defined(parameterValues.emissiveTexture)) {
fragmentShader += ' vec3 emissive = texture2D(u_emissiveTexture, ' + v_texcoord + ').rgb;\n';
fragmentShader += ' vec3 emissive = SRGBtoLINEAR3(texture2D(u_emissiveTexture, ' + v_texcoord + ').rgb);\n';
if (defined(parameterValues.emissiveFactor)) {
fragmentShader += ' emissive *= u_emissiveFactor;\n';
}
Expand All @@ -602,6 +625,7 @@ define([
}

// Final color
fragmentShader += ' color = LINEARtoSRGB(color);\n';
var alphaMode = material.alphaMode;
if (defined(alphaMode)) {
if (alphaMode === 'MASK') {
Expand Down