Ambient Occlusion Shader (bent-normal)

Hi, right well ive been looking into AO for TGEA quiet a bit over the last few months, and found a few alternatives apart from supporting a second UV channel (for pre-bake).

I came across as site which had a guide for an OpenGL equivalent, I emailed the guy and he kindly ported it to HLSL as best as he could. What you do is run the object through his app (or similar) and it produces an .xml file of the bent-normal for each vertex.

The original website - www.ozone3d.net/tutorials/ambient_occlusion.php


..."This GLSL shader can be quite easily ported to DX HLSL. In this shader I used a vertex attribute to store AO values but this not mandatory. Just store AO values (bent-normal and and occlusion term) in the color attribute of the vertex. Simple and efficient!

Here is the new GLSL shader:"

GLSL Vertex Shader:
void main(void)
 
{
	gl_Position = ftransform();
	gl_FrontColor = gl_Color;
}
 
 
GLSL Pixel Shader:
void main (void)
 
{
	vec4 vAmbient = vec4(0.9, 0.9, 0.9, 1.0);
	vAmbient.rgb *= gl_Color.w; // Modulate with occlusion term.
	gl_FragColor = vAmbient; }

And here is the HLSL equivalent:

float4x4 worldViewProj : WORLDVIEWPROJ; //our world view projection matrix
 
//application to vertex structure
struct a2v
{
   float4 position : POSITION0;
   float4 color : COLOR0;
};
 
//vertex to pixel shader structure
struct v2p
{
   float4 position : POSITION0;
   float4 color : COLOR0;
};
 
//pixel shader to screen
struct p2f
{
   float4 color : COLOR0;
};
 
//VERTEX SHADER
void vs( in a2v IN, out v2p OUT )
{
   //getting to position to object space
   OUT.position = mul(IN.position, worldViewProj);
   OUT.color = IN.color;
}
 
//VERTEX SHADER
void ps( in v2p IN, out p2f OUT )
{
   //output some color
 
   float 4 vAmbient = float4(0.9, 0.9, 0.9, 1.0);
   vAmbient.rgb *= IN.color.a; // Modulate with occlusion term.
    OUT.color = vAmbient;
 
}

Ive had a shot myself of getting into TGEA, fixed a few syntax errors but to be honest don't know what im doing with it.

What I assume is you can just run in the per-vertex file through an object definition or something? assuming it can work in TGEA at all.

So, is their a chance anyone here could have ago themselfs? im sure it would make allot of people happy, and with ODE in the new TGEA then pollysoup buildings will be almost their.

Best Regards,