Heat Distortion

.

 

Cool! Thanks for sharing

 

Looks nice

Kind of like the heat refraction shader basing on NM particles from Unite 2008 ... cool

 

Thanks for sharing! This is great for underwater distortion. Just drop it on a plane in front of the camera and bam! I changed the range to a float for more precision with the strength.

 

Hmm... if I turn of AA the texture gets inverted? Is this a DirectX issue?

 

Yes, I am that person. The attached image shows what your sample package looks like on my mac with Unity 2.6.1f3 Pro.

I have no clue what is wrong there, as I explained in the other thread, other GrabPass shaders seem to work fine.

 

Your shader already explicitly defines the queue as transparent+10. However, just to test, I tried a few other values. Interestingly, as soon as I drop into the geometry queue (Geometry,Geometry+1, ..., Geometry+999), the shader starts to partially work. That is, it correctly shows distorted grass in its entire area (with the fire particles rendered (undistorted) on top of it). Other solid geometry, like the walls and the logs are invisible within the spherical area. As soon as the queue hits Geometry+1000 (aka Transparent) it becomes the strange white egg from the picture.

So I guess the render queue is indeed somehow involved, but I still don't know what is wrong exactly.

 

I know, but it happens anyway. Something is quite messed up, but I have no idea what.

 

is thais shader work on unity pro only ?

it can't work on my secene

http://forum.unity3d.com/threads/83...can-t-work-in-my-scene-how-can-I-make-it-work

 

Yes, refraction / haze are always unity pro only
You can easily identify this in the initial posting: GrabPass is Pro only

 

Old but very interesting water and Heat solutions from forestjohnson:


http://forum.unity3d.com/threads/4285-quot-Sweet-arse-quot-water

NB: it was a project for Unity 2.x so it needs some improvements with 3.4

 

Thanks for sharing meh11.

I came across this becuase I am looking for some heat distortion for my project.

For some reason everything is flipped in the distortion except during Deffered render mode. Would you know this could be fixed?

Thanks for any help!

 

Thanks for the reply.

That didn't fix it but no problem.

 

FYI, unity 3.3+ has now a proper builtin function for calculating GrabPass coordinates (handles flipping for windows et al):

Code (csharp):

1.  float4 grabPassCoords = ComputeGrabScreenPos(o.pos) // o.pos is projected vertex

 

Hi ole!

Could you show us please, how to use the grabbed texture in screen space on the original position? (like the "render nothing" example)

I' ve tried the following in a Surface Shader:

Code (csharp):

1.  
2.     float4 sPos = ComputeGrabScreenPos(IN.screenPos); // o.pos is projected vertex
3.     float2 uv = sPos.xy / sPos.w;
4.     o.Albedo = tex2D (_GrabTexture, uv).rgb;
5.  

In forward rendering the texture is not flipped anymore, however it is not placed correctly either.
In deferred rendering it is now flipped(and placed elsewhere) where it worked before:

Code (csharp):

1.  
2.     float2 uv = IN.screenPos.xy / IN.screenPos.w;
3.     o.Albedo = tex2D (_GrabTexture, uv).rgb;
4.  

Maybe I'm doing something wrong?

Thanks!

 

hello,

pasting a simplified code derived from our glass shader here that should work in all cases (if not it's a bug) ...

Code (csharp):

1.  
2. struct appdata_t {
3.     float4 vertex : POSITION;
4.     float2 texcoord: TEXCOORD0;
5. };
6.  
7. struct v2f {
8.     float4 vertex : POSITION;
9.     float4 uvgrab : TEXCOORD0;
10.     float2 uvbump : TEXCOORD1;
11. };
12.  
13. float4 _BumpMap_ST;
14.  
15. v2f vert (appdata_t v)
16. {
17.     v2f o;
18.     o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
19.     #if UNITY_UV_STARTS_AT_TOP
20.     float scale = -1.0;
21.     #else
22.     float scale = 1.0;
23.     #endif
24.     o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y*scale) + o.vertex.w) * 0.5;
25.     o.uvgrab.zw = o.vertex.zw;
26.     o.uvbump = TRANSFORM_TEX( v.texcoord, _BumpMap );
27.     return o;
28. }
29.  
30. sampler2D _GrabTexture;
31. float4 _GrabTexture_TexelSize;
32. sampler2D _BumpMap;
33.  
34. half4 frag( v2f i ) : COLOR
35. {
36.     half2 bump = UnpackNormal(tex2D( _BumpMap, i.uvbump )).rg;
37.     float2 offset = bump * 0.1 * _GrabTexture_TexelSize.xy;
38.     i.uvgrab.xy = offset * i.uvgrab.z + i.uvgrab.xy;
39.     half4 col = tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(i.uvgrab));
40.     return col;
41. }
42.  

remember to use GrabPass {} in a pass before this one and then all you'd need to do is add some animation to the bump lookup (and maybe fade out edges etc.) to get heat haze / distortion.

 

why i use as your setp...but looks like this ...everything .. reverse....

 

But it reduce the frame rate and don't know the exact reason...

 

It reduce the frame rate and don't know the exact reason.

 

Code (csharp):

1.  
2.   // check if anti aliasing is used
3.  
4.     //if (_ProjectionParams.x < 0)
5.  
6.        screenPos.y = 1 - screenPos.y;
7.  

Just comment out the checking anti-aliasing part, then it will render correctly, but I not sure what kind impact will this bring if we turn on the AA.

--TwisterK

 

Hi All,

This looks perfect for a project I am working on but does anyone have a package with the latest version of code? I don't mind piecing it all together from these posts but if someone has a current working version, I'd love to get my hands on it.

Thanks.

 

What is the range of Heat Distortion temperature of Polysulfone and Polyetherether Ketones(PEEK) ?

 

The shader doesnt work for, its saying that i cant run subshaders on my graphics card. Im using Unity 3.5 without emulation mode and an nvidia GTX 570

 

Hey guys, I noticed a small problem when integrating this shader. It will render fog twice causing the distortion object to very obviously stand out.

This can be fixed by adding:

Code (csharp):

1. Fog { Color (0,0,0,0) }

Here's the full shader:

Code (csharp):

1.  
2. // Upgrade NOTE: replaced 'glstate.matrix.modelview[0]' with 'UNITY_MATRIX_MV'
3. // Upgrade NOTE: replaced 'glstate.matrix.mvp' with 'UNITY_MATRIX_MVP'
4.  
5. Shader "HeatDistortion" {
6.  
7. Properties {
8.  
9.     _NoiseTex ("Noise Texture (RG)", 2D) = "white" {}
10.  
11.     strength("strength", Range(0.1, 0.3)) = 0.2
12.  
13.     transparency("transparency", Range(0.01, 0.1)) = 0.05
14.  
15. }
16.  
17.  
18.  
19. Category {
20.  
21.     Tags { "Queue" = "Transparent+10" }
22.  
23.     SubShader {
24.  
25.         GrabPass {
26.  
27.             Name "BASE"
28.  
29.             Tags { "LightMode" = "Always" }
30.  
31.         }
32.  
33.        
34.  
35.         Pass {
36.  
37.             Name "BASE"
38.  
39.             Tags { "LightMode" = "Always" }
40.            
41.             Fog { Color (0,0,0,0) }
42.  
43.             Lighting Off
44.  
45.             Cull Off
46.  
47.             ZWrite On
48.  
49.             ZTest LEqual
50.  
51.             Blend SrcAlpha OneMinusSrcAlpha
52.  
53.             AlphaTest Greater 0
54.          
55.  
56. CGPROGRAM
57. // Upgrade NOTE: excluded shader from Xbox360; has structs without semantics (struct v2f members distortion)
58. #pragma exclude_renderers xbox360
59.  
60. #pragma vertex vert
61.  
62. #pragma fragment frag
63.  
64. #pragma fragmentoption ARB_precision_hint_fastest
65.  
66. #pragma fragmentoption ARB_fog_exp2
67.  
68. #include "UnityCG.cginc"
69.  
70.  
71.  
72. sampler2D _GrabTexture : register(s0);
73.  
74. float4 _NoiseTex_ST;
75.  
76. sampler2D _NoiseTex;
77.  
78. float strength;
79.  
80. float transparency;
81.  
82.  
83.  
84. struct data {
85.  
86.     float4 vertex : POSITION;
87.  
88.     float3 normal : NORMAL;
89.  
90.     float4 texcoord : TEXCOORD0;
91.  
92. };
93.  
94.  
95.  
96. struct v2f {
97.  
98.     float4 position : POSITION;
99.  
100.     float4 screenPos : TEXCOORD0;
101.  
102.     float2 uvmain : TEXCOORD2;
103.  
104.     float distortion;
105.  
106. };
107.  
108.  
109.  
110. v2f vert(data i){
111.  
112.     v2f o;
113.  
114.     o.position = mul(UNITY_MATRIX_MVP, i.vertex);      // compute transformed vertex position
115.  
116.     o.uvmain = TRANSFORM_TEX(i.texcoord, _NoiseTex);   // compute the texcoords of the noise
117.  
118.     float viewAngle = dot(normalize(ObjSpaceViewDir(i.vertex)),
119.  
120.                          i.normal);
121.  
122.     o.distortion = viewAngle * viewAngle;   // square viewAngle to make the effect fall off stronger
123.  
124.     float depth = -mul( UNITY_MATRIX_MV, i.vertex ).z;  // compute vertex depth
125.  
126.     o.distortion /= 1+depth;        // scale effect with vertex depth
127.  
128.     o.distortion *= strength;   // multiply with user controlled strength
129.  
130.     o.screenPos = o.position;   // pass the position to the pixel shader
131.  
132.     return o;
133.  
134. }
135.  
136.  
137.  
138. half4 frag( v2f i ) : COLOR
139.  
140. {  
141.  
142.     // compute the texture coordinates
143.  
144.     float2 screenPos = i.screenPos.xy / i.screenPos.w;   // screenpos ranges from -1 to 1
145.  
146.     screenPos.x = (screenPos.x + 1) * 0.5;   // I need 0 to 1
147.  
148.     screenPos.y = (screenPos.y + 1) * 0.5;   // I need 0 to 1
149.  
150.  
151.  
152.     // check if anti aliasing is used
153.  
154.     if (_ProjectionParams.x < 0)
155.  
156.         screenPos.y = 1 - screenPos.y;
157.  
158.    
159.  
160.     // get two offset values by looking up the noise texture shifted in different directions
161.  
162.     half4 offsetColor1 = tex2D(_NoiseTex, i.uvmain + _Time.xz);
163.  
164.     half4 offsetColor2 = tex2D(_NoiseTex, i.uvmain - _Time.yx);
165.  
166.    
167.  
168.     // use the r values from the noise texture lookups and combine them for x offset
169.  
170.     // use the g values from the noise texture lookups and combine them for y offset
171.  
172.     // use minus one to shift the texture back to the center
173.  
174.     // scale with distortion amount
175.  
176.     screenPos.x += ((offsetColor1.r + offsetColor2.r) - 1) * i.distortion;
177.  
178.     screenPos.y += ((offsetColor1.g + offsetColor2.g) - 1) * i.distortion;
179.  
180.    
181.  
182.     half4 col = tex2D( _GrabTexture, screenPos );
183.  
184.     col.a = i.distortion/transparency;
185.  
186.     return col;
187.  
188. }
189.  
190.  
191.  
192. ENDCG
193.  
194.         }
195.  
196.     }
197.  
198. }
199.  
200.  
201.  
202. }

 

I know this kind off an old post, but is anyone capable of making this into a 4.0 shader?

I have no experience with shaders and have no idea how to do this myself. I tried renaming and moving some stuff according to the logic in other 4.0 shaders, but without succes.

The screenshots I saw in this post look promising.

Any help would be appreciated.

 

it's great!!!

 

I am trying to use this also on 4.0... looks fine on PC and mac, shader compiles ok for OGL2 emulation.
but runs super slow on iPad3, just rendering 1/8 of screen area, goes from 30fps down to 7fps,
shame, as it looks great.

 

Hi! Sorry for resurrecting this post but I need to ask: someone knows how to port this code to a compatible DX11 syntax? I'm getting the following errors when compiling in Directx11 rendering mode:

Material doesn't have a texture property '_NoiseTex'

Material doesn't have a texture property '_NoiseTex'

Material doesn't have a float or range property 'strength'

Material doesn't have a float or range property 'transparency'

Thanks in advance for your time

 

Thanks for your help! The compilation errors are:

No subshaders can run on this graphics card
Program 'vert','vert': function return value missing semantics (compiling for d3d11_9x) at line 15

I'm running a 560GTX Ti so the first error its a little baffling. Additionally, the compiler its adding these lines to the shader code:

// Upgrade NOTE: excluded shader from DX11 and Xbox360; has structs without semantics (struct v2f members distortion)
#pragma exclude_renderers d3d11 xbox360

Struct v2 its (its the same code posted on this thread):

struct v2f {
float4 position : POSITION;
float4 screenPos : TEXCOORD0;
float2 uvmain : TEXCOORD2;
float distortion;
};

Any idea of how to solve this?

 

Well, based on the error description, you could try giving distortion a semantic... how about TEXCOORD3?

 

well done!!!

 

This didn't do anything on my project. The image rendered is still upside down.
Any ideas ?

 

Ok, got it. You need to keep the line but remove the if statement.

Code (CSharp):

1.  
2. // Upgrade NOTE: replaced 'glstate.matrix.modelview[0]' with 'UNITY_MATRIX_MV'
3. // Upgrade NOTE: replaced 'glstate.matrix.mvp' with 'UNITY_MATRIX_MVP'
4.  
5. Shader "HeatDistortion" {
6.  
7.   Properties {
8.     _NoiseTex ("Noise Texture (RG)", 2D) = "white" {}
9.     strength("strength", Range(0.1, 0.3)) = 0.2
10.     transparency("transparency", Range(0.01, 0.1)) = 0.05
11.   }
12.  
13.   Category {
14.     Tags { "Queue" = "Transparent+10" }
15.     SubShader {
16.    
17.       // http://docs.unity3d.com/Manual/SL-GrabPass.html
18.       // http://docs.unity3d.com/Manual/SL-PassTags.html
19.       GrabPass {
20.         Name "BASE"
21.         Tags { "LightMode" = "Always" } // no lighting
22.       }
23.    
24.       Pass {
25.         Name "BASE"
26.         Tags { "LightMode" = "Always" }
27.         Fog { Color (0,0,0,0) }
28.         Lighting Off
29.         Cull Off
30.         ZWrite On
31.         ZTest LEqual
32.         Blend SrcAlpha OneMinusSrcAlpha
33.         AlphaTest Greater 0
34.      
35.         CGPROGRAM
36.         // Upgrade NOTE: excluded shader from DX11 and Xbox360; has structs without semantics (struct v2f members distortion)
37.         #pragma exclude_renderers d3d11 xbox360
38.         // Upgrade NOTE: excluded shader from Xbox360; has structs without semantics (struct v2f members distortion)
39.         #pragma exclude_renderers xbox360
40.         #pragma vertex vert
41.         #pragma fragment frag
42.         #pragma fragmentoption ARB_precision_hint_fastest
43.         #pragma fragmentoption ARB_fog_exp2
44.         #include "UnityCG.cginc"
45.      
46.         // http://forum.unity3d.com/threads/what-does-register-s0-do.26816/
47.         sampler2D _GrabTexture : register(s0);
48.         float4 _NoiseTex_ST;
49.         sampler2D _NoiseTex;
50.         float strength;
51.         float transparency;
52.      
53.         struct data {
54.           float4 vertex : POSITION;
55.           float3 normal : NORMAL;
56.           float4 texcoord : TEXCOORD0;
57.         };
58.      
59.         struct v2f {
60.           float4 position : POSITION;
61.           float4 screenPos : TEXCOORD0;
62.           float2 uvmain : TEXCOORD2;
63.           float distortion;
64.         };
65.      
66.         v2f vert(data i){
67.           v2f o;
68.           o.position = mul(UNITY_MATRIX_MVP, i.vertex);      // compute transformed vertex position
69.           o.uvmain = TRANSFORM_TEX(i.texcoord, _NoiseTex);   // compute the texcoords of the noise
70.           float viewAngle = dot(normalize(ObjSpaceViewDir(i.vertex)), i.normal);
71.           o.distortion = viewAngle * viewAngle;   // square viewAngle to make the effect fall off stronger
72.           float depth = -mul( UNITY_MATRIX_MV, i.vertex ).z;  // compute vertex depth
73.           o.distortion /= 1+depth;  // scale effect with vertex depth
74.           o.distortion *= strength; // multiply with user controlled strength
75.           o.screenPos = o.position; // pass the position to the pixel shader
76.           return o;
77.         }
78.      
79.         half4 frag( v2f i ) : COLOR
80.         {
81.           // compute the texture coordinates
82.           float2 screenPos = i.screenPos.xy / i.screenPos.w;   // screenpos ranges from -1 to 1
83.           screenPos.x = (screenPos.x + 1) * 0.5;   // I need 0 to 1
84.           screenPos.y = (screenPos.y + 1) * 0.5;   // I need 0 to 1
85.        
86.           // check if anti aliasing is used
87.           //if (_ProjectionParams.x < 0) screenPos.y = 1 - screenPos.y;
88.           screenPos.y = 1 - screenPos.y;
89.        
90.           // get two offset values by looking up the noise texture shifted in different directions
91.           half4 offsetColor1 = tex2D(_NoiseTex, i.uvmain + _Time.xz);
92.           half4 offsetColor2 = tex2D(_NoiseTex, i.uvmain - _Time.yx);
93.        
94.           // use the r values from the noise texture lookups and combine them for x offset
95.           // use the g values from the noise texture lookups and combine them for y offset
96.           // use minus one to shift the texture back to the center
97.           // scale with distortion amount
98.           screenPos.x += ((offsetColor1.r + offsetColor2.r) - 1) * i.distortion;
99.           screenPos.y += ((offsetColor1.g + offsetColor2.g) - 1) * i.distortion;
100.           half4 col = tex2D( _GrabTexture, screenPos );
101.           col.a = i.distortion / transparency;
102.           return col;
103.         }
104.      
105.         ENDCG
106.       }
107.     }
108.   }
109. }

 

The shader doesn't seem to work since unity5.

 

Problems on Unity5 like this?

 

Maybe the distortion shader in the following thread works for you?
http://forum.unity3d.com/threads/horizontal-wave-distortion.295769/#post-1950999

 

Thanks for your post already found and used this shader.
Very good for static objects. somewhat tricky to use for particles.

 

Does this work on ios?