From 83936f66fbf471aca8b6887c4e43ff8052806103 Mon Sep 17 00:00:00 2001
From: karl <karl.bittner@hexaquo.at>
Date: Wed, 18 Nov 2020 16:04:44 +0100
Subject: [PATCH] Use Tangents for correct normal calculation

The normal maps are looking good now!
---
 Shaders/default-fragment.fs | 4 ++--
 Shaders/default-vertex.vs   | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/Shaders/default-fragment.fs b/Shaders/default-fragment.fs
index 5b9082e..3770a4a 100644
--- a/Shaders/default-fragment.fs
+++ b/Shaders/default-fragment.fs
@@ -5,6 +5,7 @@ in mediump vec2 TexCoord;
 in mediump vec3 Normal;
 in mediump vec3 FragPos;
 in mediump vec4 FragPosLightSpace;
+in mediump mat3 TBN;
 
 layout(binding=0) uniform sampler2D shadowMap;
 layout(binding=1) uniform sampler2D tex;
@@ -46,8 +47,7 @@ void main()
 
     // Get normal from normal map in the range [-1,1]
     mediump vec3 map_normal = normalize(texture(normalmap, TexCoord).rgb * 2.0 - 1.0);
-
-    mediump vec3 final_normal = map_normal;
+    mediump vec3 final_normal = normalize(TBN * map_normal);
 
     // Alpha Scissors
     if(texColor.a < 0.1)
diff --git a/Shaders/default-vertex.vs b/Shaders/default-vertex.vs
index 596e0b7..b82a5d0 100644
--- a/Shaders/default-vertex.vs
+++ b/Shaders/default-vertex.vs
@@ -9,6 +9,7 @@ out vec2 TexCoord;
 out vec3 Normal;
 out vec3 FragPos;
 out vec4 FragPosLightSpace;
+out mat3 TBN;
 
 uniform mat4 model;
 uniform mat4 view;
@@ -22,4 +23,9 @@ void main()
     Normal = NORMAL;
     FragPos = vec3(model * vec4(aPos, 1.0));
     FragPosLightSpace = lightSpaceMatrix * vec4(FragPos, 1.0);
+
+    vec3 T = normalize(vec3(model * vec4(TANGENT,   0.0)));
+    vec3 B = normalize(vec3(model * vec4(BITANGENT, 0.0)));
+    vec3 N = normalize(vec3(model * vec4(NORMAL,    0.0)));
+    TBN = mat3(T, B, N);
 }
\ No newline at end of file