Merge branch 'main' into KHR_texture_procedurals

KhronosGroup · Apr 1, 2024 · fca8b93 · fca8b93
2 parents 00395e6 + 44223fc
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diff --git a/extensions/2.0/Khronos/KHR_materials_iridescence/README.md b/extensions/2.0/Khronos/KHR_materials_iridescence/README.md
@@ -247,7 +247,7 @@ The two additional parameters `base_f0_color` and `specular_weight` correspond t
 
 *This section is non-normative.*
 
-The calculation of `iridescent_fresnel(...)` is described in the following sections as GLSL code at the viewing angle <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\theta_1">. For glTF an approximation of the original model (defined in the Mitsuba code example from [Belcour/Barla](#theory-documentation-and-implementations)) is used.
+The calculation of `iridescent_fresnel(...)` is described in the following sections as GLSL code at the viewing angle $\theta_1$. For glTF an approximation of the original model (defined in the Mitsuba code example from [Belcour/Barla](#theory-documentation-and-implementations)) is used.
 
 ```glsl
 vec3 iridescent_fresnel(outsideIor, iridescenceIor, baseF0, iridescenceThickness, cosTheta1) {
@@ -291,19 +291,19 @@ This simple formula is used for both dielectrics and metals. While it is physica
 
 To calculate the reflectance factors at normal incidence of both interfaces (`R0` and `R1`), the special case is used as is:
 
-<img src="https://render.githubusercontent.com/render/math?math=\large\color{gray}\displaystyle%20R%20=%20\left|\frac{n_1%20-%20n_2%20}{n_1%20%2B%20n_2%20}\right|^2">
+$$R = \left|\frac{n_1 - n_2}{n_1 + n_2 }\right|^2$$
 
 ```glsl
 float IorToFresnel0(float transmittedIor, float incidentIor) {
     return pow((transmittedIor - incidentIor) / (transmittedIor + incidentIor), 2.0);
 }
 ```
 
-To calculate the reflectances `R12` and `R23` at the viewing angles <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\theta_1"> (angle hitting the thin-film layer) and <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\theta_2"> (angle after refraction in the thin-film) Schlick Fresnel is again used. This approximation allows to eliminate the split into S and P polarization for the exact Fresnel equations.
+To calculate the reflectances `R12` and `R23` at the viewing angles $\theta_1$ (angle hitting the thin-film layer) and $\theta_2$ (angle after refraction in the thin-film) Schlick Fresnel is again used. This approximation allows to eliminate the split into S and P polarization for the exact Fresnel equations.
 
-<img src="https://render.githubusercontent.com/render/math?math=\color{gray}\theta_2"> can be calculated using Snell's law (with <img src="https://render.githubusercontent.com/render/math?math=\large\color{gray}\displaystyle%20\eta_1"> being `outsideIor` and <img src="https://render.githubusercontent.com/render/math?math=\large\color{gray}\displaystyle%20\eta_2"> being `iridescenceIor`):
+$\theta_2$ can be calculated using Snell's law (with $\eta_1$ being `outsideIor` and $\eta_2$ being `iridescenceIor`):
 
-<img src="https://render.githubusercontent.com/render/math?math=\large\color{gray}\displaystyle%20\cos(\theta_2)%20=%20\sqrt{1-\left(\frac{\eta_1}{\eta_2}\right)^2\cdot\left(1-\cos^2(\theta_1)\right)}">
+$$\cos(\theta_2) = \sqrt{1-\left(\frac{\eta_1}{\eta_2}\right)^2\left(1-\cos^2(\theta_1)\right)}$$
 
 ```glsl
 float sinTheta2Sq = pow(outsideIor / iridescenceIor, 2.0) * (1.0 - pow(cosTheta1, 2.0));
@@ -321,12 +321,12 @@ float cosTheta2 = sqrt(cosTheta2Sq);
 
 The phase shift is as follows:
 
-<img src="https://render.githubusercontent.com/render/math?math=\large\color{gray}\displaystyle%20\Delta%20\phi%20=%202%20\pi%20\lambda^{-1}\mathcal{D}">
+$$\Delta\phi=2\pi\lambda^{-1}\mathcal{D}$$
 
-and depends on the first-order optical path difference <img src="https://render.githubusercontent.com/render/math?math=\color{gray}\displaystyle%20\mathcal{D}"> (or `OPD`):
+and depends on the first-order optical path difference $\mathcal{D}$ (or `OPD`):
 
 ```glsl
-OPD = 2.0 * iridescenceIor * iridescenceThickness * cosTheta1;
+OPD = 2.0 * iridescenceIor * iridescenceThickness * cosTheta2;
 ```
 
 `phi12` and `phi23` define the base phases per interface and are approximated with `0.0` if the IOR of the hit material (`iridescenceIor` or `baseIor`) is higher than the IOR of the previous material (`outsideIor` or `iridescenceIor`) and *π* otherwise. Also here, polarization is ignored.

diff --git a/extensions/2.0/Vendor/GRIFFEL_bim_data/schema/GRIFFEL_bim_data.schema.json b/extensions/2.0/Vendor/GRIFFEL_bim_data/schema/GRIFFEL_bim_data.schema.json
@@ -17,7 +17,7 @@
                     "properties": {
                         "type": "array",
                         "uniqueItems": true,
-                        "item": {
+                        "items": {
                             "allOf": [ { "$ref": "glTFid.schema.json" } ],
                             "description": "Index of a property in the root level collection."
                         },

diff --git a/specification/2.0/ObjectModel.adoc b/specification/2.0/ObjectModel.adoc
@@ -294,13 +294,24 @@ Additional read-only properties
 
 [options="header",cols="50%,15%"]
 |====
-| Pointer                                                                                                             |  Type
-| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatTexture/extensions/KHR_texture_transform/offset`         | `float2`
-| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatTexture/extensions/KHR_texture_transform/rotation`       | `float`
-| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatTexture/extensions/KHR_texture_transform/scale`          | `float2`
-| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatNormalTexture/extensions/KHR_texture_transform/offset`   | `float2`
-| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatNormalTexture/extensions/KHR_texture_transform/rotation` | `float`
-| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatNormalTexture/extensions/KHR_texture_transform/scale`    | `float2`
+| Pointer                                                                                                                |  Type
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatTexture/extensions/KHR_texture_transform/offset`            | `float2`
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatTexture/extensions/KHR_texture_transform/rotation`          | `float`
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatTexture/extensions/KHR_texture_transform/scale`             | `float2`
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatRoughnessTexture/extensions/KHR_texture_transform/offset`   | `float2`
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatRoughnessTexture/extensions/KHR_texture_transform/rotation` | `float`
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatRoughnessTexture/extensions/KHR_texture_transform/scale`    | `float2`
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatNormalTexture/extensions/KHR_texture_transform/offset`      | `float2`
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatNormalTexture/extensions/KHR_texture_transform/rotation`    | `float`
+| `/materials/{}/extensions/KHR_materials_clearcoat/clearcoatNormalTexture/extensions/KHR_texture_transform/scale`       | `float2`
+|====
+
+== KHR_materials_dispersion
+
+[options="header",cols="50%,15%"]
+|====
+| Pointer                                                        |  Type
+| `/materials/{}/extensions/KHR_materials_dispersion/dispersion` | `float`
 |====
 
 == KHR_materials_emissive_strength