changing the terrain shader

I want to use the terrain engine to draw tree canopy by planting foliage (instead of trees)
In order to do that I need the terrain to be totally transparent so I replaced the terrain Vertex lighting shader by something like this:

Code (csharp):

1.  
2. SubShader {
3.     Pass
4.     {
5.         Lighting Off
6.         ZWrite Off
7.         //Blend One Zero
8.         ColorMask A
9.     }
10.  

It works great in the editor : the terrain is invisible when set in lighting = vertex but in any player this seems overriden by the built in shader.
So there is a bug here (#??? still waiting) but until it gets fixed, how do I work around this ?

thank you

 

you have to assign the shader to a material then assign this material to any object e.g. a simple cube which is placed in your scene. otherwise the modified shader won’t get exported…

 

I'm trying to override the billboard shader, so I have placed the billboardshader from the buildin shaderlibary in my project, and added it to a cube. But it doesn't replace the existing as I had hoped. I have tried manipulating all sorts of sensitive parts of this shader, and it has no effect. Is this not doable? I saw a post by Mr. J. Ante where he says you can override terrain shaders by adding a copy with the same name to the project. But?

Code (csharp):

1. Shader "hidden/TerrainEngine/BillboardTree" {
2.     Properties {
3.         _MainTex ("Base (RGB) Alpha (A)", 2D) = "white" {}
4.        
5.     }
6.    
7.     SubShader {
8.         Tags { "Queue" = "Transparent" }
9.        
10.         Pass {
11.  
12.             CGPROGRAM
13.             #pragma vertex Vertex
14.             #include "UnityCG.cginc"        // Get standard Unity constants
15.            
16.             struct AppData {
17.                 float4 vertex : POSITION;      
18.                 float4 color : COLOR;           // color.r, color.g, color.b
19.                 float4 texcoord : TEXCOORD0;        // UV Coordinates
20.                 float2 texcoord1 : TEXCOORD1;       // xy offset
21.             };
22.            
23.             struct v2f {
24.                 float4 pos : POSITION;
25.                 float fog : FOGC;
26.                 float4 color : COLOR0;
27.                 float4 uv : TEXCOORD0;  // [tree uv]
28.             };
29.            
30.             uniform float3 _TreeBillboardCameraRight, _TreeBillboardCameraUp;
31.             uniform float4 _TreeBillboardCameraPos;
32.             uniform float4 _TreeBillboardDistances; // x = max distance ^ 2
33.            
34.             v2f Vertex (AppData v) {
35.                 v2f o;
36.                
37.                 float4 vertex = v.vertex;
38.                 float2 xyOffset = v.texcoord1;
39.                
40.                 float4 offset = vertex - _TreeBillboardCameraPos;
41.                 float distanceSqr = dot(offset,offset);
42.                 if (distanceSqr > _TreeBillboardDistances.x)
43.                 {
44.                     xyOffset.xy = 0.0F;
45.                 }
46.                
47.                 // Apply billboard extrusion
48.                 vertex.xyz += xyOffset.x * _TreeBillboardCameraRight.xyz;
49.                 vertex.xyz += xyOffset.y * _TreeBillboardCameraUp.xyz;
50.                
51.                 float4 pos = mul (glstate.matrix.mvp, vertex);
52.                 o.pos = pos;
53.                 o.fog = o.pos.z;
54.                 o.uv = v.texcoord;
55.                 o.color = v.color;
56.                 return o;
57.             }
58.             ENDCG          
59.  
60.             // Premultiplied alpha
61.             ColorMask rgb
62.             // Doesn't actually look so bad!
63.             Blend SrcAlpha OneMinusSrcAlpha
64.  
65.             ZWrite Off
66.             Cull Off
67.             AlphaTest Greater 0
68.             SetTexture [_MainTex] { combine texture * primary, texture }
69.         }
70.     }
71.    
72.     Fallback Off
73. }

 

Hi,

If I understood well, there is a way to override the existing terrain material/shader ??
Could someone confirm this please ? and how exactly it is done.

Thanks.

 

Terrain inherits from MonoBehaviour, and MonoBehaviour has a 'renderer' variable. Thus, it is in theory possible to assign a new material to terrain renderer:
terrain.renderer.material = mymaterial;

 

It is possible to replace the existing terrain shaders. They need to be named the same and reside in a folder named Resources. Restarting Unity might be required.

 

Yeap, I just found out more or less and was playing with the builtin shaders.
Thanks!

 

Does anyone know if there is a way to generate tangents for the terrain ? or a way to get bumpmap without tangent

I was happy to see that we can still change the shader, but the vertex entry is quite limited.

Any hope to get a better terrain/material/shader handling in the next version ?

Thanks.