Still no Fog?

[Andy Gilbert]

I still dont get how we dont have any fog, especially now we have terrain?

 

Im sure OpenGL has fog features out-of-the-box? Cant we just have them?

 

Andy

[YouGroove]

Humm ....

Fog and shaders are not compatible from what i read long time ago.

Some special work is needed if you need fog.

 

A cheap solution :

Make several aligned transparent background big planes always facing camera.

By using several transparent layers you'll heav fog impression.

But indeed not as good as real fog.

[YouGroove]

What i found :

 

HLSL fog shader :

http://ploobs.com.br/?p=1868

shader fog for dummies :

https://www.dropbox.com/s/z05aql3qp3dsly5/Codea%20shaders.pdf

OpenGL fog :

http://www.ozone3d.net/tutorials/glsl_fog/

 

All it needs is you to put at hard work now on this shader

[Andy Gilbert]

YouGroove, i dont want to use transparent backgrounds, otherwise i would do? Ide like to have the ability to turn on fog.

 

This isnt a "find an alternative" forum, its a sugesstions forum? Please stop posting, unnecessary replies.

 

Andy

[shadmar]

If you want to hack in your own fog, add this to the bottom of all fragment shaders you use just before } to add fog.

 

vec4 fog=vec4(1,1,1,0.05); // R,G,B,strength
#define LOG2 1.442695
float z = gl_FragCoord.z / gl_FragCoord.w;
float fogFactor = clamp(exp2(-fog.w*fog.w*z*z*LOG2),0.0,1.0);
gl_FragColor = mix(vec4(fog.xyz,1.0), gl_FragColor, fogFactor);

 

For terrain :

 

terrain.shader, just before gl_FragData[0] = outcolor; add :

 

vec4 fog=vec4(1,1,1,0.05); // R,G,B,strength
#define LOG2 1.442695
float z = gl_FragCoord.z / gl_FragCoord.w;
float fogFactor = clamp(exp2(-fog.w*fog.w*z*z*LOG2),0.0,1.0);
outcolor = mix(vec4(fog.xyz,1.0), outcolor, fogFactor);

 

A more elegant way would be to add vec4 fog as a uniform and send color and density from your app using SetVec4

 

 

EDIT: sorry Andy if I'm also derailing your post.

Edited September 18, 2013 by shadmar

[Andy Gilbert]

Hi shad, thanks and no derailing going on. I very much welcome useful replies. Ill give that ago, it seems like it will do the trick for now. You really are a shader wiz!

 

Thanks shad

 

Andy

[YouGroove]

Ok , i will let shadmar and other programmers reply to programming or features missing on suggestion forum so.

[Josh]

The plan is to create a post-processing list in the editor and then you can just add effects like fog, SSDO, and whatever other crazy effects Shadmar makes.

[gamecreator]

Love that. And I mentioned this before but if possible, please make it so that we can set the strength of any effect, especially in our code. Something like SetEffect(fog, 0.5); which would enable fog at half strength. Of course you'd know the better way to implement that function but that's the idea.

[Nexerade]

If you want to hack in your own fog, add this to the bottom of all fragment shaders you use just before } to add fog.

 

vec4 fog=vec4(1,1,1,0.05); // R,G,B,strength
#define LOG2 1.442695
float z = gl_FragCoord.z / gl_FragCoord.w;
float fogFactor = clamp(exp2(-fog.w*fog.w*z*z*LOG2),0.0,1.0);
gl_FragColor = mix(vec4(fog.xyz,1.0), gl_FragColor, fogFactor);

 

For terrain :

 

terrain.shader, just before gl_FragData[0] = outcolor; add :

 

vec4 fog=vec4(1,1,1,0.05); // R,G,B,strength
#define LOG2 1.442695
float z = gl_FragCoord.z / gl_FragCoord.w;
float fogFactor = clamp(exp2(-fog.w*fog.w*z*z*LOG2),0.0,1.0);
outcolor = mix(vec4(fog.xyz,1.0), outcolor, fogFactor);

 

A more elegant way would be to add vec4 fog as a uniform and send color and density from your app using SetVec4

 

 

EDIT: sorry Andy if I'm also derailing your post.

 

I have a black screen when I put this to ambientlight.shares. I guess it's no more working? :c

[macklebee]

I have a black screen when I put this to ambientlight.shares. I guess it's no more working? :c

ambientlight.shares? the ambientlight.shader? yeah dont do that. This topic was from over two years ago - there have been many updates since then. Also, have you checked the shadmar's Post Effect shaders in the workshop? I believe klepto's fog is available in there.