I’m trying to get a shader working which relies on coloring parts of the world a certain color.

I can’t seem to get it to work however; no matter what I do, I’m not able to get actual world coordinates of what’s being rendered on screen.

The vertex shader (reduced to the simplest nonworking case):

[java]

uniform mat4 g_WorldViewProjectionMatrix;

uniform mat4 g_WorldMatrix;

uniform float m_tileSize;

uniform int m_maxTileX;

uniform int m_maxTileZ;

uniform float[ARRSIZE] m_fowData;

uniform float m_cameraX;

uniform float m_cameraZ;

in vec4 inPosition;

in vec2 inTexCoord;

out vec2 texCoord;

out float fogFactor;

void main() {

vec4 worldCoord = (g_WorldMatrix * inPosition );

if (worldCoord.x < 1024) {

fogFactor = 1.0;

}

else fogFactor = 0.0;

```
texCoord = inTexCoord;
vec2 pos = (g_WorldViewProjectionMatrix * inPosition).xy;
gl_Position = vec4(pos, 0.0, 1.0);
```

}

[/java]

The line [java]vec4 worldCoord = (g_WorldMatrix * inPosition );[/java] is as far as I understand supposed to give the actual world coordinates of the vertex being rendered, but it seems to for some reason be returning a pixel-on-screen related value. Hence the line [java]if (worldCoord.x < 1024) {[/java] - 1024 happens to be the width of the window, and is a pivot point where any values below that half-color the screen, and any values above that fully color the screen.

The fragment shader:

[java]

#import “Common/ShaderLib/MultiSample.glsllib”

uniform COLORTEXTURE m_Texture;

uniform vec4 m_FowColor;

in vec2 texCoord;

in float fogFactor;

void main() {

vec4 texVal = getColor(m_Texture, texCoord);

gl_FragColor = mix(texVal, m_FowColor,fogFactor);

}

[/java]

And the material definition:

[java]

MaterialDef FogOfWar {

```
MaterialParameters {
Int NumSamples
Int NumSamplesDepth
Texture2D Texture
Vector4 FowColor
FloatArray fowData
Float tileSize
Int maxTileX
Int maxTileZ
Int arrSize
Float cameraX;
Float cameraZ;
}
Technique {
VertexShader GLSL150: MatDefs/Post/Fow15.vert
FragmentShader GLSL150: MatDefs/Post/Fow15.frag
WorldParameters {
WorldMatrix
WorldViewProjectionMatrix
WorldViewMatrix
}
Defines {
ARRSIZE : arrSize
}
}
Technique {
VertexShader GLSL100: MatDefs/Post/Fow.vert
FragmentShader GLSL100: MatDefs/Post/Fow.frag
WorldParameters {
WorldMatrix
WorldViewProjectionMatrix
WorldViewMatrix
}
Defines {
ARRSIZE : arrSize
}
}
```

}

[/java]

The output:

The main problem with this output is that the filter applied to the screen doesn’t change at all as the camera is moved around, even though it’s supposed to be based on world coordinates. Plus, I’m not sure how I ended up with a color gradient when the only possible colors should be fully green or normal.

Am I doing anything obviously wrong?

Thanks in advance.