// Thanks for the contribution Jonas // http://29a.ch/2012/7/19/webgl-terrain-rendering-water-fog uniform sampler2D specularMap; uniform sampler2D normalMap; uniform vec4 baseWaterColor; uniform vec4 blendColor; uniform float frequency; uniform float animationSpeed; uniform float amplitude; uniform float specularIntensity; uniform float fadeFactor; vec4 getNoise(vec2 uv, float time, float angleInRadians) { float cosAngle = cos(angleInRadians); float sinAngle = sin(angleInRadians); // time dependent sampling directions vec2 s0 = vec2(1.0/17.0, 0.0); vec2 s1 = vec2(-1.0/29.0, 0.0); vec2 s2 = vec2(1.0/101.0, 1.0/59.0); vec2 s3 = vec2(-1.0/109.0, -1.0/57.0); // rotate sampling direction by specified angle s0 = vec2((cosAngle * s0.x) - (sinAngle * s0.y), (sinAngle * s0.x) + (cosAngle * s0.y)); s1 = vec2((cosAngle * s1.x) - (sinAngle * s1.y), (sinAngle * s1.x) + (cosAngle * s1.y)); s2 = vec2((cosAngle * s2.x) - (sinAngle * s2.y), (sinAngle * s2.x) + (cosAngle * s2.y)); s3 = vec2((cosAngle * s3.x) - (sinAngle * s3.y), (sinAngle * s3.x) + (cosAngle * s3.y)); vec2 uv0 = (uv/103.0) + (time * s0); vec2 uv1 = uv/107.0 + (time * s1) + vec2(0.23); vec2 uv2 = uv/vec2(897.0, 983.0) + (time * s2) + vec2(0.51); vec2 uv3 = uv/vec2(991.0, 877.0) + (time * s3) + vec2(0.71); uv0 = fract(uv0); uv1 = fract(uv1); uv2 = fract(uv2); uv3 = fract(uv3); vec4 noise = (texture2D(normalMap, uv0)) + (texture2D(normalMap, uv1)) + (texture2D(normalMap, uv2)) + (texture2D(normalMap, uv3)); // average and scale to between -1 and 1 return ((noise / 4.0) - 0.5) * 2.0; } czm_material czm_getMaterial(czm_materialInput materialInput) { czm_material material = czm_getDefaultMaterial(materialInput); float time = czm_frameNumber * animationSpeed; // fade is a function of the distance from the fragment and the frequency of the waves float fade = max(1.0, (length(materialInput.positionToEyeEC) / 10000000000.0) * frequency * fadeFactor); float specularMapValue = texture2D(specularMap, materialInput.st).r; // note: not using directional motion at this time, just set the angle to 0.0; vec4 noise = getNoise(materialInput.st * frequency, time, 0.0); vec3 normalTangentSpace = noise.xyz * vec3(1.0, 1.0, (1.0 / amplitude)); // fade out the normal perturbation as we move further from the water surface normalTangentSpace.xy /= fade; // attempt to fade out the normal perturbation as we approach non water areas (low specular map value) normalTangentSpace = mix(vec3(0.0, 0.0, 50.0), normalTangentSpace, specularMapValue); normalTangentSpace = normalize(normalTangentSpace); // get ratios for alignment of the new normal vector with a vector perpendicular to the tangent plane float tsPerturbationRatio = clamp(dot(normalTangentSpace, vec3(0.0, 0.0, 1.0)), 0.0, 1.0); // fade out water effect as specular map value decreases material.alpha = specularMapValue; // base color is a blend of the water and non-water color based on the value from the specular map // may need a uniform blend factor to better control this material.diffuse = mix(blendColor.rgb, baseWaterColor.rgb, specularMapValue); // diffuse highlights are based on how perturbed the normal is material.diffuse += (0.1 * tsPerturbationRatio); material.normal = normalize(materialInput.tangentToEyeMatrix * normalTangentSpace); material.specular = specularIntensity; material.shininess = 10.0; return material; }