如何在文本网格中添加一个法线，使其正确地发光?

I'm using a text mesh to place text on a 3D object, but as you all know, the text mesh does not have any normals...

我正在使用一个文本网格将文本放置在一个3D对象上，但是正如你们所知道的，文本网格没有任何法线……

http://docs.unity3d.com/Documentation/Components/class-TextMesh.html

http://docs.unity3d.com/Documentation/Components/class-TextMesh.html

...so it does not light correctly. I've done a search and found many people having trouble with lighting 3D text mesh because of it doesn't have any normals, but I haven't found a solution to adding normals to a text mesh object, so that is my question.

…所以它不能正确地发光。我做了一个搜索，发现很多人在使用3D文本网格时遇到了麻烦，因为它没有任何法线，但是我还没有找到向文本网格对象添加法线的解决方案，所以这是我的问题。

How can I add a normal to a text mesh so that it lights correctly?

如何在文本网格中添加一个法线，使其正确地发光?

Thanks so much in advance for your wisdom!

非常感谢您的智慧!

1 个解决方案

#1

I did something similar for lighting a 3D texture. I hope my answer isn't overkill. So this code was a hack I wrote awhile back, it's inefficient and only supports a single directional light (helpful cg lighting tuts here). Hopefully this is enough to get you started.

我做了一些类似的事情来点燃3D纹理。我希望我的回答不过分。所以这段代码是我之前写的一个技巧，它的效率很低，并且只支持一个方向光(这里有用的cg照明tuts)。希望这足够让你开始。

To create a 3D texture using my code below you have to go through a little more work:

要使用我下面的代码创建一个3D纹理，你需要做更多的工作:

1. Create an empty game object
2. 创建一个空的游戏对象
3. Attach Component->Mesh->Text Mesh
4. 附加组件- >网- >文本网格
5. Attach Component TextMeshNormals (included below)
6. 附加组件文本法线(包括以下)
7. Attach Component->Mesh->Mesh Renderer
8. 附加组件- >网- >网格渲染器
9. Assign a material to the Mesh Renderer that uses my GUI/LitText shader below
10. 为使用下面的GUI/LitText着色器的网格渲染器分配一个材质

In the shader you'll notice a text normal attribute. In practice you would have your gameObject's Update() method update the _Normal property with the direction the text is facing so that it reflects a change in orientation. The text is planar so 1 normal is all we need. To test I manually set the normal to (0,0,-1,1), since the default Text Mesh faces down -Z.

在着色器中，您将注意到一个文本normal属性。在实践中，您将有您的gameObject的Update()方法，该方法将使用文本所面向的方向更新_Normal属性，以反映方向的变化。文本是平面的，所以我们只需要1法线。为了测试我手动设置了正常到(0,0，-1,1)，因为默认的文本网格是向下的-Z。

Because this script doesn't run in the editor, your text won't show up until you run a scene in preview.

因为这个脚本不会在编辑器中运行，所以您的文本将不会出现，直到您在预览中运行一个场景。

The shader:

材质:

Shader "GUI/LitText" { 
Properties { 
   _MainTex ("Font Texture", 2D) = "white" {} 
   _Color ("Text Color", Color) = (1,1,1,1) 
   _Normal ("Text Normal",Vector) = (0,0,0,1)
} 

SubShader {
    Blend SrcAlpha OneMinusSrcAlpha
    Pass { 
        Color [_Color] 
        SetTexture [_MainTex] { 
            combine primary, texture * primary 
        } 
    } 
    pass {
         Tags { "LightMode" = "ForwardBase" } 

         CGPROGRAM

         #pragma vertex vert  
         #pragma fragment frag 

         uniform sampler2D _MainTex;  
         uniform float4 _Color; // define shader property for shaders
         uniform float4 _Normal;

         // The following built-in uniforms (apart from _LightColor0) 
         // are defined in "UnityCG.cginc", which could be #included 
         uniform float4 unity_Scale; // w = 1/scale; see _World2Object
         uniform float3 _WorldSpaceCameraPos;
         uniform float4x4 _Object2World; // model matrix
         uniform float4x4 _World2Object; // inverse model matrix 
            // (all but the bottom-right element have to be scaled 
            // with unity_Scale.w if scaling is important) 
         uniform float4 _WorldSpaceLightPos0; 
            // position or direction of light source
         uniform float4 _LightColor0; 
            // color of light source (from "Lighting.cginc")

         struct vertexInput {
            float4 vertex : POSITION;
            float3 normal : NORMAL;
            float4 texcoord : TEXCOORD0;
         };
         struct vertexOutput {
            float4 pos : SV_POSITION;
            float4 col : COLOR;
            float4 tex : TEXCOORD0;
         };

         vertexOutput vert(vertexInput input) 
         {
            vertexOutput output;

            float4x4 modelMatrix = _Object2World;
            float4x4 modelMatrixInverse = _World2Object; 

            float3 normalDirection = normalize(float3(mul(_Normal, modelMatrixInverse)));
            float3 lightDirection = normalize(float3(_WorldSpaceLightPos0));

            float3 diffuseReflection = float3(_LightColor0) * float3(_Color)
               * max(0.0, dot(normalDirection, lightDirection));

            output.col = float4(diffuseReflection, 1.0);
            output.pos = mul(UNITY_MATRIX_MVP, input.vertex);
            output.tex = input.texcoord;
            return output;
         }

         float4 frag(vertexOutput input) : COLOR
         {
            half4 color = tex2D(_MainTex, float2(input.tex));
            // use color.a to get alpha from text texture, rgb comes from vertex shader                        
            return float4(input.col.r,input.col.g,input.col.b,color.a);
         }

         ENDCG
    }
}
}

And the helper script:

和辅助脚本:

public class TextMeshNormals : MonoBehaviour {
    private TextMesh textMesh;

    // Use this for initialization
    void Start () {
        // reassign font texture to our material
        textMesh = transform.GetComponent<TextMesh>();
        renderer.material.mainTexture = textMesh.font.material.mainTexture;
    }
}

Update Unity 4.5.X use this slightly updated version:

4.5更新统一。X使用这个稍微更新的版本:

Shader "GUI/LitText" { 
Properties { 
   _MainTex ("Font Texture", 2D) = "white" {} 
   _Color ("Text Color", Color) = (1,1,1,1) 
   _Normal ("Text Normal",Vector) = (0,0,0,1)
} 

SubShader {
    Blend SrcAlpha OneMinusSrcAlpha
    Pass { 
        Color [_Color] 
        SetTexture [_MainTex] { 
            combine primary, texture * primary 
        } 
    } 
    pass {
         Tags { "LightMode" = "ForwardBase" } 

         CGPROGRAM

         #pragma vertex vert  
         #pragma fragment frag 

         uniform sampler2D _MainTex;  
         uniform float4 _Color; // define shader property for shaders
         uniform float4 _Normal;
         uniform float4 _LightColor0; 
             // color of light source (from "Lighting.cginc")
         struct vertexInput {
            float4 vertex : POSITION;
            float3 normal : NORMAL;
            float4 texcoord : TEXCOORD0;
         };
         struct vertexOutput {
            float4 pos : SV_POSITION;
            float4 col : COLOR;
            float4 tex : TEXCOORD0;
         };

         vertexOutput vert(vertexInput input) 
         {
            vertexOutput output;

            float4x4 modelMatrix = _Object2World;
            float4x4 modelMatrixInverse = _World2Object; 

            float3 normalDirection = normalize(float3(mul(_Normal, modelMatrixInverse)));
            float3 lightDirection = normalize(float3(_WorldSpaceLightPos0));

            float3 diffuseReflection = float3(_LightColor0) * float3(_Color)
               * max(0.0, dot(normalDirection, lightDirection));

            output.col = float4(diffuseReflection, 1.0);
            output.pos = mul(UNITY_MATRIX_MVP, input.vertex);
            output.tex = input.texcoord;
            return output;
         }

         float4 frag(vertexOutput input) : COLOR
         {
            half4 color = tex2D(_MainTex, float2(input.tex));
            // use color.a to get alpha from text texture, rgb comes from vertex shader                        
            return float4(input.col.r,input.col.g,input.col.b,color.a);
         }

         ENDCG
    }
}
}