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Displacing vertex

Discussion in 'Shaders' started by jan1984, Jun 13, 2008.

  1. jan1984

    jan1984

    Joined:
    May 30, 2008
    Posts:
    43
    hi guys i have this simple shader wherein i want to displace the vertices but i get the error "" on line 23.Cud somebody point out wat i'm doing wrong?

    Shader "Underwater Effect" {
    Properties {
    _Color ("Main Color", Color) = (1,1,1,1)
    _MainTex ("Base (RfGB)", 2D) = "white" {}
    }

    Pass {

    CGPROGRAM
    #pragma vertex vert

    #include "UnityCG.cginc"
    #include "AutoLight.cginc"

    uniform float4 _MainTex_ST;

    vert (appdata_base v)
    {
    float Waviness = 5.0f;
    v.vertex.x += Mathf.Sin(Time.time + v.vertex.y * 0.1f) * Waviness;
    }
    ENDCG

    }

    Fallback "Diffuse"

    }

    another side question..
    do i need uniform float4 _MainTex_ST;?
    wat is that for?i actually copied my code from another shader and went on removing unwanted stuff.the above variable was not getting used even in that shader but with a lot of things happening behind the curtains in shaderlab i didnt want to remove this 1
     
    jan1984, Jun 13, 2008
    #1

  2. Eric5h5

    Eric5h5

    Volunteer Moderator Moderator

    Joined:
    Jul 19, 2006
    Posts:
    32,401
    Have you read the responses in your other topic? Really, you need to read the shaderlab docs. That code's not even Cg; there's no way it will come close to working.

    --Eric
     
    Eric5h5, Jun 13, 2008
    #2

  3. Aras

    Aras

    Unity Technologies

    Joined:
    Nov 7, 2005
    Posts:
    4,770
    Your shader like this gives 5 errors (no SubShader block, and the rest in Cg code).

    Here is how it should be (I removed Properties block as well, you said you want minimal shader):
    Code (csharp):
    1.  
    2. Shader "Underwater Effect" {
    3. SubShader {
    4. Pass {
    5.  
    6. CGPROGRAM
    7. #pragma vertex vert
    8. #include "UnityCG.cginc"
    9.  
    10. float4 vert (appdata_base v) : POSITION
    11. {
    12.     float Waviness = 5.0f;
    13.     v.vertex.x += sin(_Time.y + v.vertex.y * 0.1f) * Waviness;
    14.     return mul(glstate.matrix.mvp, v.vertex);
    15. }
    16. ENDCG
    17.  
    18. }
    19. }
    20. }
    Basically, like someone replied in another thread, inside of shaders you don't have access to .NET calls (so no Time.time or Mathf.Sin there). Cg has a built-in function to calculate sine ("sin"). Time value can either be passed manually from your script, or you can use _Time built-in variable.

    If you don't use it in the shader, then you don't need it. Variables ending with _ST are used by built-in Unity shaders to apply texture's tiling offset values. As your shader does not use textures, there's no tiling&offset to apply.
     
    Aras, Jun 13, 2008
    #3

  4. jan1984

    jan1984

    Joined:
    May 30, 2008
    Posts:
    43
    Thx dude that helped.Although not including the subshader part was my bad.i do have it in place.thx again
     
    jan1984, Jun 13, 2008
    #4

  5. jan1984

    jan1984

    Joined:
    May 30, 2008
    Posts:
    43
    hey i lost track of that post for some reason and i checked it only after reading this 1.i apologize for that

    well i did search for shaderlab docs but cudnt find 1 proper 1.do have any link where i cud find 1?i know cg but using it along with shaderlab has me confused and i feel like u cud combine the features for more powerful shaders.but yeah a shaderlab doc will definitely help as i'm totally new to it.
    Thx
     
    jan1984, Jun 13, 2008
    #5