History: Offset Bump Ambient Lightmap

            {maketoc}

Hello, after some working on shaders, i have modified the offset sample to work with ambient light and lightmaps. It works only for 1 light, but includes specular. Updating to more lights should be easy. It is in CG code, so you can use it with DirectX and OpenGL.

{IMG(src="img/wiki_up/Bumplight.jpg", thumb="y", button="y", rel="box[g]", stylebox=border, width="150", title="Image Sample", desc="Image Sample")}{IMG}

It also shows how to use LOD for Materials, using a simple lightmapped texture for low-end cards.

!!The Material
{CODE(wrap="1", colors="c++")}// Bump map with Parallax offset vertex program, support for this is required
vertex_program SingleBumpVP cg 
{ 
   source singlebump.cg 
   entry_point main_vp 
   profiles vs_1_1 arbvp1 
} 

// Bump map with parallax fragment program 
fragment_program SingleBumpFP cg 
{ 
   source singlebump.cg 

   default_params 
   { 
       param_named lightmapactive float2 1.0 1.0 
   } 

   entry_point main_fp 
   profiles ps_2_0 arbfp1 
} 

material vg/singlebump 
{ 
   lod_distances 400 

  // This is the preferred technique which uses both vertex and 
   // fragment programs, supports coloured lights 
   technique 
   { 
      // do the lighting  and bump mapping with parallax pass 
      // NB we don't do decal texture here because this is repeated per light 
      pass 
      { 
        
         // Vertex program reference 
         vertex_program_ref SingleBumpVP 
         { 
            param_named_auto lightPosition light_position_object_space 0 
            param_named_auto eyePosition camera_position_object_space 
            param_named_auto worldViewProj worldviewproj_matrix 
         } 

         // Fragment program 
         fragment_program_ref SingleBumpFP 
         { 
      param_named_auto lightAmbient ambient_light_colour 0 
            param_named_auto lightDiffuse light_diffuse_colour 0 
            param_named_auto lightSpecular light_specular_colour 0 
       
      // 1 active, 0 deactive. The second parameter will be the lightmap force (still not implemented) 
      param_named lightmapactive float2 0.0 0.0 

            // Parallax Height scale and bias 
            param_named scaleBias float4 0.0 -0.0 1 0 
  
         } 
          
         // NORMAL + HEIGHT MAP 
         texture_unit 
         { 
      texture_alias normalmap 
            texture cam_ronda_c_88_bump.bmp 
            tex_coord_set 0 
         } 

         // DIFFUSE 
         texture_unit 
         { 
      texture_alias diffusemap 
            texture cam_ronda_c_88.bmp 
            tex_coord_set 1 
         } 

      // LIGHTMAP 
         texture_unit 
         { 
      texture_alias lightmap 
            texture Caja01MapaSombras.bmp 
      tex_coord_set 2       
         } 
      } 
   } 
  
   // Simple no-shader fallback 
   technique 
   { 
   lod_index 1 
      pass 
      { 
         // Base diffuse texture map 
         texture_unit 
         { 
      texture_alias diffusemap 
            texture cam_ronda_c_88.bmp 
      tex_coord_set 0 
         } 

      // LIGHTMAP 
         texture_unit 
         { 
            texture_alias lightmap 
            texture white.bmp 
         tex_coord_set 2 
         colour_op modulate 
         } 

     } 
   } 

}{CODE}

!!The CG PROGRAM
{CODE(wrap="1", colors="c++")}/* Bump mapping with Parallax offset vertex program 
   In this program, we want to calculate the tangent space light end eye vectors 
   which will get passed to the fragment program to produce the per-pixel bump map 
   with parallax offset effect. 
*/ 

/* Vertex program that moves light and eye vectors into texture tangent space at vertex */ 

void main_vp(float4 position   : POSITION, 
              float3 normal      : NORMAL, 
              float2 uv         : TEXCOORD0, 
              float3 tangent     : TEXCOORD1, 
              float2 uvlm         : TEXCOORD2, 
              // outputs 
              out float4 oPosition    : POSITION, 
              out float2 oUv          : TEXCOORD0, 
              out float3 oLightDir    : TEXCOORD1, // tangent space 
             out float3 oEyeDir       : TEXCOORD2, // tangent space 
             out float3 oHalfAngle    : TEXCOORD3, // 
       out float2 ouvlm        : TEXCOORD4, 
              // parameters 
              uniform float4 lightPosition, // object space 
              uniform float3 eyePosition,   // object space 
              uniform float4x4 worldViewProj) 
{  
   // calculate output position 
   oPosition = mul(worldViewProj, position); 

   // pass the main uvs straight through unchanged 
   oUv = uv; 

   // lightmap uv direct 
   ouvlm = uvlm; 

   // calculate tangent space light vector 
   // Get object space light direction 
   float3 lightDir = normalize(lightPosition.xyz -  (position * lightPosition.w)); 
   float3 eyeDir = eyePosition - position.xyz; 
    
   // Calculate the binormal (NB we assume both normal and tangent are 
   // already normalised) 
   // NB looks like nvidia cross params are BACKWARDS to what you'd expect 
   // this equates to NxT, not TxN 
   float3 binormal = cross(tangent, normal); 
    
   // Form a rotation matrix out of the vectors 
   float3x3 rotation = float3x3(tangent, binormal, normal); 
    
   // Transform the light vector according to this matrix 
   lightDir = normalize(mul(rotation, lightDir)); 
   eyeDir = normalize(mul(rotation, eyeDir)); 

   oLightDir = lightDir; 
   oEyeDir = eyeDir; 
   oHalfAngle = normalize(eyeDir + lightDir); 
} 

// General functions 

// Expand a range-compressed vector 
float3 expand(float3 v) 
{ 
   return (v - 0.5) * 2; 
} 

// THE LIGTHTMAPACTIVE IS: 
//lightmapactive[0] if active = 1.0 
//lightmapactive[1] multiplier (still not implemented) 

void main_fp(float2 uv : TEXCOORD0, 
   float3 lightDir : TEXCOORD1, 
   float3 eyeDir : TEXCOORD2, 
   float3 halfAngle : TEXCOORD3, 
   float2 uvlm : TEXCOORD4, 
   uniform float2 lightmapactive, 
   uniform float3 lightAmbient, 
   uniform float3 lightDiffuse, 
   uniform float3 lightSpecular, 
   uniform float4 scaleBias, 
   uniform sampler2D diffuseMap, 
   uniform sampler2D normalHeightMap, 
   uniform sampler2D lightMap, 
   out float4 oColor : COLOR) 
{ 
   // get the height using the tex coords 
   float height = tex2D(normalHeightMap, uv).a; 

   // scale and bias factors    
   float scale = scaleBias.x; 
   float bias = scaleBias.y; 

   // calculate displacement    
   float displacement = (height * scale) + bias; 
    
   float3 uv2 = float3(uv, 1); 
    
   // calculate the new tex coord to use for normal and diffuse 
   float2 newTexCoord = ((eyeDir * displacement) + uv2).xy; 
    
   // get the new normal and diffuse values 
   float3 normal = expand(tex2D(normalHeightMap, newTexCoord).xyz); 
   float3 diffuse = tex2D(diffuseMap, newTexCoord).xyz; 
    
   float3 specular = pow(saturate(dot(normal, halfAngle)), 32) * lightSpecular; 
   float3 difusa = (diffuse * saturate(dot(normal, lightDir)) * lightDiffuse); 
   float3 ambiental = diffuse*lightAmbient; 
   float3 col = ambiental + difusa + specular; 
       
   // MAX DIFFUSE 
   if (col[0] > diffuse[0]) col[0] = diffuse[0]; 
   if (col[1] > diffuse[1]) col[1] = diffuse[1]; 
   if (col[2] > diffuse[2]) col[2] = diffuse[2]; 

   // LIGHTMAP 
   if (lightmapactive[0] == 1.0) 
      { 
      float3 lm = tex2D(lightMap,uvlm).xyz; 
      col = col * lm; 
      } 

   // SPECULAR 
   col = col + specular; 

   oColor = float4(col, 1); 
}{CODE}