Cheap (and easy) Glass

Hey kids,

I thought I would share some quick and easy glass for low rent applications.
We are using this in an iPhone title and it's working great.

I've includes two images. One shows it in action and the other provides an example of how to create a specular map for it.






///////////////////////////////////////////////////////

Shader "EnvMapGlass" {

Properties {
_EnvMap ("EnvMap", 2D) = "black" { TexGen SphereMap }
}

SubShader {
SeperateSpecular On
Pass {
Name "BASE"
Cull Front
//Blend One OneMinusDstColor
Blend One One
BindChannels {
Bind "Vertex", vertex
Bind "normal", normal
}

SetTexture [_EnvMap] {
combine texture
}
}
Pass {
Name "BASE"
ZWrite on
Blend One One
BindChannels {
Bind "Vertex", vertex
Bind "normal", normal
}

SetTexture [_EnvMap] {
combine texture
}
}

}

Fallback off
}

 

Sweet! Nice effect and thanks for sharing.

 

take away the back face culling pass and the screening and you have really good reflection annd chrome.

 

So...

Code (csharp):

1.  
2.  
3. ///////////////////////////////////////////////////////
4.  
5. Shader "EnvMapGlass" {
6.  
7. Properties {
8.    _EnvMap ("EnvMap", 2D) = "black" { TexGen SphereMap }
9.    }
10.  
11. SubShader {
12.    SeperateSpecular On
13.       Pass {
14.          Name "BASE"
15.             Cull Front
16.             Blend One One
17.             BindChannels {
18.                Bind "Vertex", vertex
19.                Bind "normal", normal
20.             }
21.  
22.             SetTexture [_EnvMap] {
23.                combine texture
24.             }
25.       }
26.  
27.       Pass {
28.          Name "BASE"
29.          ZWrite on
30.          Blend One One
31.          BindChannels {
32.          Bind "Vertex", vertex
33.          Bind "normal", normal
34.       }
35.  
36.       SetTexture [_EnvMap] {
37.          combine texture
38.       }
39.    }
40. }
41.  
42. Fallback off
43. }

becomes...

Code (csharp):

1.  
2.  
3. ///////////////////////////////////////////////////////
4.  
5. Shader "EnvMapGlass" {
6.  
7. Properties {
8.    _EnvMap ("EnvMap", 2D) = "black" { TexGen SphereMap }
9.    }
10.  
11. SubShader {
12.    SeperateSpecular On
13.  
14.       Pass {
15.          Name "BASE"
16.          ZWrite on
17.          Blend One One
18.          BindChannels {
19.          Bind "Vertex", vertex
20.          Bind "normal", normal
21.       }
22.  
23.       SetTexture [_EnvMap] {
24.          combine texture
25.       }
26.    }
27. }
28.  
29. Fallback off
30. }

Is that right?

 

Great shader, really simple but totally effective!

Just one question: how can I modify this shader in order to get access to transparency and "glass tint"?

Thanks

 

Thanks!! This shader is really neat!!

 

Yello,

just gonna dig up this and say thanks for a sweet shader! Very useful.

 

The specular map is missing for me, could someone re-post it?

 

Here you go.

 

*bump*

Yea I'd like to second eXKR's request for some guidance on how to access transparency and the like...I tried to no avail...

Thanks!
-Steve

 

Thank you for this quick and simple env mapping shader.

However, there are two problems with it:

First, we had the effect that the shader became non-transparent in our builds, while it worked fine in the editor. This is a problem with the rendering queue, which seems to differ (or maybe even yield non-deterministic results) between those two. We solved that problem by explicitly assigning the correct render queue position in the shader.

Second, the "Blend One One" is a fully additive blending, and will often burn out (="overexpose") areas with a reflection. There are two variations that yield better results.
The first is "Blend One OneMinusSrcColor", which is probably what you want. It prevents overexposure, while still giving full brightness where the reflection is strongest. NOTE that the Unity ShaderLab documentation for this is WRONG, listing this as "Blend One OneMinusDstColor" - which results in strong color distortion, amongst other problems). Note that this is only correct for greyscale envmaps.
The other would be "Blend SrcAlpha OneMinusSrcAlpha", which would be the standard setting for "correct" alpha blending, and can be used if your Envmap is a "real" color map with a designated alpha channel. As long as your envmap is greyscale without alpha, you should use the former blendfunction.

So the modified shader looks like this:

Code (csharp):

1. ///////////////////////////////////////////////////////
2.  
3. Shader "EnvMapGlass" {
4.  
5. Properties {
6.    _EnvMap ("EnvMap", 2D) = "black" { TexGen SphereMap }
7.    }
8.  
9. SubShader {
10.    SeperateSpecular On
11.    Tags {"Queue" = "Transparent" }
12.  
13.       Pass {
14.          Name "BASE"
15.          ZWrite on
16.          //Blend One One                       // additive
17.          Blend One OneMinusSrcColor          // soft additive
18.          //Blend SrcAlpha OneMinusSrcAlpha     // real alpha blending
19.          BindChannels {
20.          Bind "Vertex", vertex
21.          Bind "normal", normal
22.       }
23.  
24.       SetTexture [_EnvMap] {
25.          combine texture
26.       }
27.    }
28. }
29.  
30. Fallback off
31. }

 

Hey how can i add ad a difuse color to this?

 

Thanks for share..

 

So in my scene, this shader does nothing, I don't see a material, am I missing something?

 

I thought I would give some input on this thread.

The shader posted by cgoran is great but it appears to break batching. If you are doing an iOS game, your enemy is draw calls and your friend is the automatic batching. If you have poly objects under 300 verts they will be automatically batched thus reducing your draw calls. So you can have... say... 4 poly objects, and if they are batched, they only take one draw call. I need batching in my application. Of course if you are only applying the shader to one object, then batching may not be an issue for you. I'm not a shader expert so I don't know why cgoran's shader breaks batching. If anyone knows, I would love to learn. This brings me to Wolfram's adjustments.

Wolfram's shader appears to have some mistyped brackets. I fixed the bracket situation and figured I would post his corrected code. It works for me and more importantly it allows the glass transparancy while reenabling batching. (very useful in iOS development).

My only problem with this implementation of glass for iOS is it seems to work great for spheres but if you flatten out a cube to a scale of say X:2 Y:.1 Z:2 (forming somewhat of a platform), then depending on the x position on the screen, your platform appears almost entirely opaque white. I think this is what Wolfram was observing. If you stick with the additive command of Blend One One and comment out the soft additive and real alpha, then that white opaqueness is really overexposed and blown out. It looks pretty bad. That's why I use the soft additive command Blend One OneMinusSrcColor and have commented out the other two options.

If anyone knows if there is a way to adjust or further minimize that white opaqueness, that would be really helpful. It is my guess it has something to do with the fact that we are use a spheremap as our texture instead of say a cubemap. When a cubemap would be less beneficial for performance and memory in iOS.

Allan

Code (csharp):

1.  
2. // Upgrade NOTE: replaced 'SeperateSpecular' with 'SeparateSpecular'
3. Shader "Mobile/EnvMapGlass1"
4. {
5.  
6.  Properties
7.  {
8.     _EnvMap ("EnvMap", 2D) = "black" { TexGen SphereMap }
9.  }
10.  
11.  SubShader
12.  {
13.      SeparateSpecular On
14.      Tags {"Queue" = "Transparent" }
15.  
16.       Pass
17.       {
18.          Name "BASE"
19.          ZWrite on
20.          //Blend One One                       // additive
21.          Blend One OneMinusSrcColor          // soft additive
22.          //Blend SrcAlpha OneMinusSrcAlpha     // real alpha blending
23.          BindChannels
24.          {
25.           Bind "Vertex", vertex
26.           Bind "normal", normal
27.         }
28.  
29.        SetTexture [_EnvMap]
30.        {
31.           combine texture
32.        }
33.       }
34.    }
35. }
36.  

 

Thanks for the share

 

how can I make this shader work

thank for help

 

thx for sharing, this looks great!!

 

It's great, but the second image doesn't show so I have no idea to create the texture. Can anybody re-post the image or make some describe?
Thinks.

 

Read the whole thread, instead of the first post.... -_-

 

So does this shader only work on Spheres?

It's fine in the engine, but when i Build to ios only the spheres display correctly, have i missed something?

Thanks.