Add existing to tracked

node_modules/@cesium/engine/Source/Shaders/Materials/RimLightingMaterial.glsl

@@ -0,0 +1,21 @@
+uniform vec4 color;
+uniform vec4 rimColor;
+uniform float width;
+
+czm_material czm_getMaterial(czm_materialInput materialInput)
+{
+    czm_material material = czm_getDefaultMaterial(materialInput);
+
+    // See http://www.fundza.com/rman_shaders/surface/fake_rim/fake_rim1.html
+    float d = 1.0 - dot(materialInput.normalEC, normalize(materialInput.positionToEyeEC));
+    float s = smoothstep(1.0 - width, 1.0, d);
+
+    vec4 outColor = czm_gammaCorrect(color);
+    vec4 outRimColor = czm_gammaCorrect(rimColor);
+
+    material.diffuse = outColor.rgb;
+    material.emission = outRimColor.rgb * s;
+    material.alpha = mix(outColor.a, outRimColor.a, s);
+
+    return material;
+}