Light weakening

src/main.go

@@ -23,6 +23,9 @@ const EPS = 0.1
 const PI = math.Pi
 
 const SOFT_SHADOW_COEFF = 16
+const LIGHT_POWER_EXP = 2.0
+
+var LIGHT_POWER_FAC float64 = 2.0
 
 var lightPos Vector3
 var scene SDF
@@ -33,8 +36,8 @@ var screenPhysicalSize float64
 var cameraPos Vector3
 
 func init() {
-	lightPos = Vector3{100, -400, 400}
+	lightPos = Vector3{0, -200, 100}
-
+	LIGHT_POWER_FAC = math.Pow(lightPos.Length(), LIGHT_POWER_EXP) * LIGHT_POWER_FAC
 	cameraPos = Vector3{0, -10, 25}
 	screenSpherical = Vector3{10, PI/2 + 0.2, PI / 2}
 	screenPhysicalSize = 5

src/ray_marching.go

@@ -9,26 +9,30 @@ import (
 )
 
 func phongShading(point Vector3, normal Vector3, mat Material) Vector3 {
-	lightVec := (lightPos.Sub(point)).Normalized()
+	lightVecNormalized := (lightPos.Sub(point)).Normalized()
-	reflectLight := Reflect(lightVec, normal)
+
+	reflectLight := Reflect(lightVecNormalized, normal)
 	eyeVec := (cameraPos.Sub(point)).Normalized()
 	brutMat := mat.GetMaterialBrut()
 	ambiant := brutMat.ambiantColor.GetColor(point)
 
-	diffusePower := brutMat.diffuseFac * max(0, normal.Dot(lightVec))
+	diffusePower := brutMat.diffuseFac * max(0, normal.Dot(lightVecNormalized))
 	diffuse := brutMat.diffuseColor.GetColor(point).Scale(diffusePower)
 
 	specularPower := brutMat.specularFac * math.Pow(max(0, reflectLight.Dot(eyeVec)), brutMat.specularExp)
 	specular := brutMat.specularColor.GetColor(point).Scale(specularPower)
 
-	return ambiant.Add(diffuse).Add(specular)
+	return (ambiant.Add(diffuse).Add(specular))
 }
 
 func shadow(point Vector3) float64 {
-	direction := (lightPos.Sub(point)).Normalized()
+	lightVec := (lightPos.Sub(point))
+	lightVecLength := lightVec.Length()
+	direction := lightVec.Scale(1 / lightVecLength)
 	p := point.Add(direction.Scale(5 * EPS))
 	res := 1.0
 	dist_total := 0.0
+	lightPower := LIGHT_POWER_FAC / math.Pow(lightVecLength, LIGHT_POWER_EXP)
 	for range MAX_STEP {
 		dist := scene.Distance(p)
 		if dist < EPS {
@@ -41,7 +45,7 @@ func shadow(point Vector3) float64 {
 		dist_total += dist
 		p.Radd(direction.Scale(dist))
 	}
-	return res
+	return res * lightPower
 }
 
 func reflect(point Vector3, direction Vector3, normal Vector3, mat Material, reflectNumber int) Vector3 {
@@ -67,7 +71,7 @@ func rayMarch(origin Vector3, direction Vector3, reflectNumber int) (bool, Vecto
 			mat := scene.GetMaterial(p)
 			normal := Gradient(scene, p, EPS).Normalized()
 			phongShade := phongShading(p, normal, mat)
-			shadowCoeff := max(shadow(p), 0.3)
+			shadowCoeff := max(shadow(p), 0.1)
 			reflectColor := reflect(p, direction, normal, mat, reflectNumber)
 			return true, phongShade.Add(reflectColor).Scale(shadowCoeff)
 			// return true, phongShading(p, normal, *mat)