Fixed shadow back projections

data/shaders/raytracing/raytracing.comp

@@ -12,6 +12,7 @@ layout (binding = 0, rgba8) uniform writeonly image2D resultImage;
 #define MAXLEN 1000.0
 #define SHADOW 0.5
 #define RAYBOUNCES 2
+#define REFLECTIONS true
 #define REFLECTIONSTRENGTH 0.4
 #define REFLECTIONFALLOFF 0.5
 
@@ -68,7 +69,7 @@ void reflectRay(inout vec3 rayD, in vec3 mormal)
 
 float lightDiffuse(vec3 normal, vec3 lightDir) 
 {
-	return clamp(dot(normal, lightDir), 0.25, 1.0);
+	return clamp(dot(normal, lightDir), 0.1, 1.0);
 }
 
 float lightSpecular(vec3 normal, vec3 lightDir, float specularFactor)
@@ -91,6 +92,7 @@ float sphereIntersect(in vec3 rayO, in vec3 rayD, in Sphere sphere)
 		return -1.0;
 	}
 	float t = (-b - sqrt(h)) / 2.0;
+
 	return t;
 }
 
@@ -144,14 +146,16 @@ int intersect(in vec3 rayO, in vec3 rayD, inout float resT)
 	return id;
 }
 
-float calcShadow(in vec3 rayO, in vec3 rayD, in int id)
+float calcShadow(in vec3 rayO, in vec3 rayD, in int objectId, inout float t)
 {
-	//todo: avoid backprojection
 	for (int i = 0; i < spheres.length(); i++)
 	{
+		if (spheres[i].id == objectId)
+			continue;
 		float tSphere = sphereIntersect(rayO, rayD, spheres[i]);
-		if (tSphere > EPSILON)
+		if ((tSphere > EPSILON) && (tSphere < t))
 		{
+			t = tSphere;
 			return SHADOW;
 		}
 	}		
@@ -210,9 +214,10 @@ vec3 renderScene(inout vec3 rayO, inout vec3 rayD, inout int id)
 		return color;
 
 	id = objectID;
-	
+
 	// Shadows
-	color *= calcShadow(pos, lightVec, objectID);
+	t = length(ubo.lightPos - pos);
+	color *= calcShadow(pos, lightVec, id, t);
 	
 	// Fog
 	color = fog(t, color);	
@@ -236,9 +241,8 @@ void main()
 	int id = 0;
 	vec3 finalColor = renderScene(rayO, rayD, id);
 	
-	const bool reflections = true;
 	// Reflection
-	if (reflections)
+	if (REFLECTIONS)
 	{
 		float reflectionStrength = REFLECTIONSTRENGTH;
 		for (int i = 0; i < RAYBOUNCES; i++)