Hi guys,

I had to stop working on my Game for quiete some time but now I am continuing with Susanne Wigard's Book on how to programm a basic game engine.

Now I copied the fx-File from the CD that came with the book but for some reason my specular-light-dot is not behaving as planned (see pictures below).
The fx-File:

//--------------------------------------------------------------------------------------
// Datei: Glanzlicht.fx
//
// Glanzlicht
//
// Susanne Wigard 2009
//--------------------------------------------------------------------------------------
//--------------------------------------------------------------------------------------
// Global variables
//--------------------------------------------------------------------------------------
cbuffer cb0 //Standardshader
{
float4 g_MaterialAmbientColor; // Material's ambient color
float4 g_MaterialDiffuseColor; // Material's diffuse color
float3 g_vLightDir; // Light's direction in world space, normalized
float4 g_LightDiffuse; // Light's diffuse color
float g_fTime; // App's time in seconds
float4x4 g_mWorld; // World matrix for object
float4x4 g_mWorldViewProjection; // World * View * Projection matrix
}
cbuffer cb1 //Für Glanzlicht
{
float4 g_LightSpecular = float4(1, 1, 1, 1);
float g_SpecularPower;

float4x4 g_mView;
float4x4 g_mProj;
}
//--------------------------------------------------------------------------------------
// Vertex shader output structure
//--------------------------------------------------------------------------------------
struct VS_OUTPUT
{
float4 Position : SV_Position; // vertex position
float4 Diffuse : COLOR0; // vertex diffuse color (note that COLOR0 is clamped from 0..1)
float2 TextureUV : TEXCOORD0; // vertex texture coords
};
//--------------------------------------------------------------------------------------
// Vertexshader mit Glanzlicht
//--------------------------------------------------------------------------------------
VS_OUTPUT RenderMitGlanzlichtVS( float4 vPos : POSITION,
float3 vNormal : NORMAL)
{
VS_OUTPUT Output;
float4 worldPos = mul(vPos, g_mWorld);
float4 cameraPos = mul(worldPos, g_mView); //Position im Koordinatensystem der Kamera
Output.Position = mul(cameraPos, g_mProj);
float3 vNormalWorldSpace;
vNormalWorldSpace = normalize(mul(vNormal, (float3x3)g_mWorld)); // normal (world space)
float3 halfAngle = normalize(normalize(-cameraPos) + g_vLightDir);
float NDotH = max(0, dot(halfAngle, vNormalWorldSpace));
Output.Diffuse.rgb = g_MaterialDiffuseColor * g_LightDiffuse *
max(0,dot(vNormalWorldSpace, g_vLightDir))
+ g_LightSpecular * pow(NDotH, g_SpecularPower)
+ g_MaterialAmbientColor;
Output.Diffuse.a = 1.0f;

return Output;
}
//--------------------------------------------------------------------------------------
// Standard-Pixelshader ohne Textur
//--------------------------------------------------------------------------------------
float4 SimplePS( VS_OUTPUT In ) : SV_Target
{
return In.Diffuse;
}
//--------------------------------------------------------------------------------------
// Rendern mit Glanzlicht ohne Textur
//--------------------------------------------------------------------------------------
fxgroup Glanzlicht
{
technique11 RenderMitGlanzlicht
{
pass P0
{
SetVertexShader( CompileShader(vs_4_0, RenderMitGlanzlichtVS()));
SetGeometryShader( NULL );
SetPixelShader( CompileShader(ps_4_0, SimplePS()));
}
}
}



What happens is.... strange. The diffuse and the ambient light work as intended. The specular lighting however screws up.
Lets say the Sphere is always centered around (0,0,0) and has a radius of 2.0f.
The Camera starts at (0.0f, 0.0f, 5.0f) and is directed towards (0,0,0).
The light source ist at (0,0,10.0f) and it's direction vector is (0,0,1.0f).

Then I see the following:
(pictures attached with 1_ prefix)
[attachment=11126:1_beginning.png]
[attachment=11127:1_looking_up_slightly.PNG]
[attachment=11128:1_moving_to_the_right_looking_down_slightly.png]

However, if I change the light source to (10.0f, 0, 0) pointing at (1.0f,0,0) I see the following:
(pictures attached with 2_ prefix)
[attachment=11129:2_beginning.png]
[attachment=11130:2_moving_to_the_left.png]
[attachment=11131:2_moving_to_the_left_and_up.png]

As you can see in the second setup the white spot is not moving at all.

I mean the view matrix is used for the specular highlight but also for the calculation of the output position, so I assume it is correctly set. Maybe something went wrong during vector conversions (3 and 4 entries)? Or is it something more obvious?

Yours,
Nicholas


P.S.: I've only started working with different rendering techniques. Up until now I always used a default fx-file so please keep it simple ;).

Thank you,
works like a charm!

Yours,
Nicholas