From 60730edb7b5fd10f940e1ceeddcd0f3246da4b6b Mon Sep 17 00:00:00 2001
From: Crizomb <clementbart.45@gmail.com>
Date: Fri, 26 Sep 2025 22:57:06 +0200
Subject: [PATCH] bug solving phong specular

---
 material.go     |  4 ++--
 ray_marching.go | 20 ++++++++++----------
 vec3.go         |  2 +-
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/material.go b/material.go
index f78f30f..51f0b16 100644
--- a/material.go
+++ b/material.go
@@ -42,8 +42,8 @@ func DefaultMaterial(ambiantColor Color) Material {
 		ambiantColor:    ambiantColor,
 		diffuseColor:    Vector3{255, 255, 255},
 		diffuseFac:      1.0,
-		specularColor:   Vector3{1.0, 1.0, 1.0},
-		specularFac:     0.5,
+		specularColor:   Vector3{0, 255, 0},
+		specularFac:     1.0,
 		specularExp:     32.0,
 		reflectanceFac:  0.0,
 		reflectanceTint: Vector3{1.0, 1.0, 1.0},
diff --git a/ray_marching.go b/ray_marching.go
index e1b3f47..b077eff 100644
--- a/ray_marching.go
+++ b/ray_marching.go
@@ -11,34 +11,33 @@ import (
 )
 
 const MAX_DIST = 1000.0
-const MAX_STEP = 100
-const EPS = 0.1
+const MAX_STEP = 1000
+const EPS = 0.01
 const WIDTH = 500
 const HEIGHT = 500
 const PI = math.Pi
 
-var lightPos Vector3 = Vector3{0, 200, 400}
-var sphere Sphere = Sphere{Vector3{0, 100, 10}, 10, WHITE_GREY_GRID_MAT}
+var lightPos Vector3 = Vector3{0, -200, 600}
+var sphere Sphere = Sphere{Vector3{0, 100, 10}, 10, RED_MAT}
 var plane Plane = Plane{Vector3{0, 0, 1}, -10, GRID_OF_GRID_MAT}
 var scene UnionSDF = UnionSDF{sphere, plane}
 
-var cameraPos Vector3 = Vector3{0, -10, 0}
+var cameraPos Vector3 = Vector3{0, -10, 30}
 
 // radius, theta, phi
-var screenSpherical Vector3 = Vector3{10, PI / 2, PI / 2}
+var screenSpherical Vector3 = Vector3{10, PI/2 + 0.2, PI / 2}
 var screenPhysicalSize float64 = 5
 
 func phongShading(point Vector3, normal Vector3, mat Material) Vector3 {
 	lightVec := (lightPos.Sub(point)).Normalized()
-	reflectLight := Reflect(lightVec, normal)
+	reflectLight := Reflect(lightVec.Scale(-1), normal)
 	eyeVec := (cameraPos.Sub(point)).Normalized()
-
 	ambiant := mat.ambiantColor.GetColor(point).Scale(0.1)
 
-	diffusePower := mat.diffuseFac * max(0, normal.Dot(lightVec)) * 0.5
+	diffusePower := mat.diffuseFac * max(0, normal.Dot(lightVec))
 	diffuse := mat.diffuseColor.GetColor(point).Scale(diffusePower)
 
-	specularPower := mat.specularFac * math.Pow(max(0, reflectLight.Dot(eyeVec)), mat.specularExp)
+	specularPower := mat.specularFac * math.Pow(max(0, -reflectLight.Dot(eyeVec)), mat.specularExp)
 	specular := mat.specularColor.GetColor(point).Scale(specularPower)
 
 	return ambiant.Add(diffuse).Add(specular)
@@ -89,6 +88,7 @@ func genImage() *rl.Image {
 			} else {
 				fr, fg, fb = 0, 0, 0
 			}
+			fr, fg, fb = Clamp(fr, 0, 255), Clamp(fg, 0, 255), Clamp(fb, 0, 255)
 			r, g, b := uint8(fr), uint8(fg), uint8(fb)
 			rl.ImageDrawPixel(image, int32(pixel_x), int32(pixel_y), rl.Color{R: r, G: g, B: b, A: 255})
 		}
diff --git a/vec3.go b/vec3.go
index 8bc99af..1b68568 100644
--- a/vec3.go
+++ b/vec3.go
@@ -69,7 +69,7 @@ func (u Vector3) Min(x float64) Vector3 {
 // i incident, n normal. Both vector should be normalized
 func Reflect(i Vector3, n Vector3) Vector3 {
 	y := i.Dot(n)
-	return i.Add(n.Scale(2 * y))
+	return (i.Add(n.Scale(2 * y))).Normalized()
 }
 
 // Todo : Refract