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--- 0.8.4:normalmap-material [2022/06/15 19:34] – admin
+++ 0.8.4:normalmap-material [2022/06/17 10:45] (current) – [Normal Maps] admin
@@ Line 4: / Line 4: @@
 The **TGorillaNormalMapMaterialSource** is inherited from TGorillaDefaultMaterialSource, supports multiple light sources and enables normal mapping functionality in vertex- and fragmentshader: **GORILLA_GLSL_DEFINE_NORMALMAP**
+{{:0.8.4:mat_normalmap.jpg?nolink|}}
+===== Definition =====
 In 3D computer graphics, normal mapping (or Dot3 bump mapping) is a technique used for faking the lighting of bumps and dents – an implementation of bump mapping. It is used to add details without using more polygons. A common use of this technique is to greatly enhance the appearance and details of a low polygon model by generating a normal map from a high polygon model or height map.
@@ Line 9: / Line 13: @@
 [source: https://en.wikipedia.org/wiki/Normal_mapping]
+===== In General =====
 The shading model configured by default is the Blinn-Phong algorithm.
@@ Line 14: / Line 20: @@
 Using this material source will provide a new published property called **NormalMap**.
 It also supplies the optional **DisplacementMap** property to apply a vertex manipulation texture.
+===== Normal Maps =====
+Using normal maps is quite easy. You can find example textures everywhere and many graphic tools like Photoshop or GIMP are able to build them.
+They have a blueish-greenish look, like this example:
+{{:0.8.4:brick-n.jpg?nolink|400}}
+__WARNING:__ Because Gorilla3D is using OpenGL you have to be careful with the source. NormalMaps are different between OpenGL and DirectX.
+In a naive way they are flipped. But the result can be very different.
+__NOTICE:__ We do only support normal maps for OpenGL. In case you have a DirectX normal map in your texture set, you need to convert it yourself.
+For conversion have a closer look at this article: [[https://help.ambientcg.com/02-Using%20the%20assets/Normal_map_styles.html#:~:text=Editing%20the%20map%20itself,color%20channel%20and%20invert%20it.]]
+===== Example =====
+<file pascal>
+uses
+  Gorilla.Material.NormalMap;
+var FNormalMapMaterial : TGorillaNormalMapMaterialSource;
+FNormalMapMaterial := TGorillaNormalMapMaterialSource.Create(GorillaViewport1);
+FNormalMapMaterial.Parent := GorillaViewport1;
+FNormalMapMaterial.Texture.LoadFromFile('layingrock-c.jpg');
+FNormalMapMaterial.NormalMap.LoadFromFile('layingrock-n.jpg');
+FNormalMapMaterial.NormalIntensity := 1.0;
+</file>