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How do I mask off specific parts from a plane or cube?
I've been messing around with various methods to create an energymeter-like GUI-element.
This is what I would like to generate:
As I see it, I have two options:
Create a sprite for each level the blue bar could be at.
Create the blue bar using a plane/cube inside Unity that I scale along the Y-axis, with the grey lines in front of the blue bar, and the "empty" texture as the bottom-layer.
Solution #2 would be the best in my opinion, but how should i do this? I've tried to do this with this culling-shader, but that only generates this result:
In other words; the masking isn't happening dynamically - as when I scale it, the culling texture is scaled as well.
Can anyone help me out? Am I trying to solve this in all the wrong ways?
Thank you for your time.
Answer by robert · Dec 03, 2009 at 04:25 PM
You could use the masking shader you linked to with success, but the mask texture would have to contain a ramp from white to black and you would be controlling the status (the energy percentage or whatnot) by setting the _Cutoff property of the material from a script.
Or you can forget the ramp texture and use the shader pasted below instead. :)
To use it, create a material using that shader, drop it on a quad (with good UVs of course) and assign the texture of the blue bar to it (the texture's alpha channel will be nicely taken into account as well). You can now take a look at the material in the inspector and slide the "Progress" slider to see what happens.
From a script you would control the meter by calling:
renderer.material.SetFloat("_Progress", myCurrentEnergyLevelBetween0and1);
And here's the shader:
Shader "Custom/ProgressBar" {
Properties { _Color ("Color", Color) = (1,1,1,1) _MainTex ("Main Tex (RGBA)", 2D) = "white" {} _Progress ("Progress", Range(0.0,1.0)) = 0.0 }
SubShader { Tags { "Queue"="Overlay+1" } ZTest Always Blend SrcAlpha OneMinusSrcAlpha Pass {
CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc"
uniform sampler2D _MainTex; uniform float4 _Color; uniform float _Progress;
struct v2f { float4 pos : POSITION; float2 uv : TEXCOORD0; };
v2f vert (appdata_base v) { v2f o; o.pos = mul (glstate.matrix.mvp, v.vertex); o.uv = TRANSFORM_UV(0);
return o;
}
half4 frag( v2f i ) : COLOR { half4 color = tex2D( _MainTex, i.uv); color.a = i.uv.x < _Progress; return color_Color; }
ENDCG
}
}
}
It works very well but i'm using this on a 3d plane in-game and it gets drawn on over everything, and doesn't take other objects into account. Is it possible for you to revise this so it doesn't get on top?
Works great! Thank you :) @Talemon: like Peppercat says: "you have to replace the word "Overlay+1" in the shader with "Transparent"
Awesome! This is exactly what I've been looking for! Well, almost. This makes the bar go from right to left. For anyone interested, to make it go from left to right, change "color.a = i.uv.x < _Progress;" to "color.a = i.uv.x > (1.0 - _Progress);"
Answer by jonas-echterhoff · Dec 03, 2009 at 01:57 PM
You could create a custom mesh of a plane, and adjust the UVs to only show the relevant parts of the texture. Then you can draw that, either manually, using Graphics.DrawMeshNow, or using a normal MeshRenderer component.
Answer by Peppercat · Oct 23, 2012 at 08:04 PM
Hi Talemon! Maybe my answer it's a little late, but you have to replace the word "Overlay+1" in the shader with "Transparent", so your plane respect its position in the render. I hope this helps! :)
An thanks, Robert, for the shader, it's working perfectly :3