I am trying to create a normal map from a height map in HLSL. I followed this http://stackoverflow.com/a/5284527/451136 which is for GLSL. Here is how I translated GLSL to HLSL:
GLSL:
uniform sampler2D unit_wave
noperspective in vec2 tex_coord;
const vec2 size = vec2(2.0,0.0);
const ivec3 off = ivec3(-1,0,1);
vec4 wave = texture(unit_wave, tex_coord);
float s11 = wave.x;
float s01 = textureOffset(unit_wave, tex_coord, off.xy).x;
float s21 = textureOffset(unit_wave, tex_coord, off.zy).x;
float s10 = textureOffset(unit_wave, tex_coord, off.yx).x;
float s12 = textureOffset(unit_wave, tex_coord, off.yz).x;
vec3 va = normalize(vec3(size.xy,s21-s01));
vec3 vb = normalize(vec3(size.yx,s12-s10));
vec4 bump = vec4( cross(va,vb), s11 );HLSL:
sampler2D image : register(s0);
noperspective float2 TEXCOORD;
static const float2 size = (2.0,0.0);
static const int3 off = (-1,0,1);
float4 main(float2 uv : TEXCOORD) : COLOR
{
float4 color = tex2D(image, uv);
float s11 = color.x;
float s01 = tex2D(image, uv + off.xy).x;
float s21 = tex2D(image, uv + off.zy).x;
float s10 = tex2D(image, uv + off.yx).x;
float s12 = tex2D(image, uv + off.yz).x;
float3 va = normalize((size.xy,s21-s01));
float3 vb = normalize((size.yx,s12-s10));
float4 bump = (cross(va,vb), s11);
return bump;
}
The output is a black and white image, with the darker pixels being more transparent (since the alpha is the height).
How can I generate a normal map like this http://www.filterforge.com/filters/3051-normal.jpg from a height map?
