playcanvas/build/playcanvas/src/scene/shader-lib/chunks/lit/frag/refractionDynamic.js

PlayCanvas WebGL game engine

var refractionDynamicPS = "\nuniform float material_invAttenuationDistance;\nuniform vec3 material_attenuation;\nvec3 evalRefractionColor(vec3 refractionVector, float gloss, float refractionIndex) {\n	vec4 pointOfRefraction = vec4(vPositionW + refractionVector, 1.0);\n	vec4 projectionPoint = matrix_viewProjection * pointOfRefraction;\n	vec2 uv = getGrabScreenPos(projectionPoint);\n	float iorToRoughness = (1.0 - gloss) * clamp((1.0 / refractionIndex) * 2.0 - 2.0, 0.0, 1.0);\n	float refractionLod = log2(uScreenSize.x) * iorToRoughness;\n	vec3 refraction = texture2DLod(uSceneColorMap, uv, refractionLod).rgb;\n	return refraction;\n}\nvoid addRefraction(\n	vec3 worldNormal, \n	vec3 viewDir, \n	float thickness, \n	float gloss, \n	vec3 specularity, \n	vec3 albedo, \n	float transmission,\n	float refractionIndex,\n	float dispersion\n#if defined(LIT_IRIDESCENCE)\n	, vec3 iridescenceFresnel,\n	float iridescenceIntensity\n#endif\n) {\n	vec3 modelScale;\n	modelScale.x = length(vec3(matrix_model[0].xyz));\n	modelScale.y = length(vec3(matrix_model[1].xyz));\n	modelScale.z = length(vec3(matrix_model[2].xyz));\n	vec3 scale = thickness * modelScale;\n	vec3 refractionVector = normalize(refract(-viewDir, worldNormal, refractionIndex)) * scale;\n	vec3 refraction = evalRefractionColor(refractionVector, gloss, refractionIndex);\n	#ifdef LIT_DISPERSION\n		float halfSpread = (1.0 / refractionIndex - 1.0) * 0.025 * dispersion;\n		float refractionIndexR = refractionIndex - halfSpread;\n		refractionVector = normalize(refract(-viewDir, worldNormal, refractionIndexR)) * scale;\n		refraction.r = evalRefractionColor(refractionVector, gloss, refractionIndexR).r;\n		float refractionIndexB = refractionIndex + halfSpread;\n		refractionVector = normalize(refract(-viewDir, worldNormal, refractionIndexB)) * scale;\n		refraction.b = evalRefractionColor(refractionVector, gloss, refractionIndexB).b;\n	#endif\n	vec3 transmittance;\n	if (material_invAttenuationDistance != 0.0)\n	{\n		vec3 attenuation = -log(material_attenuation) * material_invAttenuationDistance;\n		transmittance = exp(-attenuation * length(refractionVector));\n	}\n	else\n	{\n		transmittance = refraction;\n	}\n	vec3 fresnel = vec3(1.0) - \n		getFresnel(\n			dot(viewDir, worldNormal), \n			gloss, \n			specularity\n		#if defined(LIT_IRIDESCENCE)\n			, iridescenceFresnel,\n			iridescenceIntensity\n		#endif\n		);\n	dDiffuseLight = mix(dDiffuseLight, refraction * transmittance * fresnel, transmission);\n}\n";

export { refractionDynamicPS as default };