Opengl GLSL法线贴图问题

Question

我的法线贴图存在问题，并且卡在我出错的地方。地图似乎在模型上，但不在正确的空间中。可变的眼睛就是相机的位置。切线在程序中计算，它们是正确的。

顶点着色器：

void main() 
{  

    vec3 EyeSpaceNormal = normalize(vec3(NormalMatrix * VertexNormal)); 
    vec3 EyeSpaceTangent = normalize(vec3(NormalMatrix * vec3(VertexTangent))); 

    TexCoord = VertexUV; 
    vec3 bitangent = normalize(cross(EyeSpaceNormal, EyeSpaceTangent)) * VertexTangent.w; 

    mat3 TBN = mat3(EyeSpaceTangent, bitangent, EyeSpaceNormal); 

    TangentLightDirection = vec3(normalize(LightDirection) * TBN); 
    TangentEye = vec3(normalize(eye) * TBN); 

    Normal = EyeSpaceNormal; 
    VertPosition = vec3(ModelViewMatrix * vec4(VertexPosition,1.0));  

    gl_Position = MVP * vec4(VertexPosition,1.0); 
} 

破片着色器：

void main() 
{  
    vec3 ReturnColour; 
    vec3 TextureNormal_tangentspace = normalize(texture2D(NormalMap, TexCoord).rgb * 2.0 - 1.0); 

    vec3 diffuse = intensity * vec3(0.0,1.0,0.0) * max(0,dot(normalize(TextureNormal_tangentspace), normalize(-TangentLightDirection))); 
    vec3 specular; 

    //Specular 
    vec3 VertexToEye = normalize(TangentEye - VertPosition); 
    vec3 LightReflect = normalize(reflect(normalize(TangentLightDirection), TextureNormal_tangentspace)); 
    float SpecularFactor = dot(VertexToEye, LightReflect); 
    SpecularFactor = pow(SpecularFactor, Shininess); 

    if(SpecularFactor > 0) 
    { 
     specular = intensity * vec3(0.0,1.0,0.0) * SpecularFactor; 
    } 

    ReturnColour = diffuse + specular;  

    FragColor = vec4(ReturnColour, 1.0); 
} 

Answer 1

我最后awnsner：Normal mapping and phong shading with incorrect specular component 见，是如何计算出的镜面因素。

1）您的代码：

dot(VertexToEye, LightReflect) 

必须是：

max(dot(VertexToEye, LightReflect), 0.0) 

这需要钳负值到零，因为在镜面计算，我们有指数（怎么说Reto Koradi）！ 2）如果在编译着色器时看不到错误，请尝试使用glGetProgramInfoLog函数。看到它：

vec3 specular; 
... 
if(SpecularFactor > 0) 
{ 
    specular = intensity * vec3(0.0,1.0,0.0) * SpecularFactor; 
} 

如果镜面等于我们变量未定义错误。

替换：

vec3 specular; 

由：

vec3 specular = vec3(0.0); 

附：像浮，VEC 2，VEC 3浮点型变量更好地利用浮点值（0.0）......这是关于：

if(SpecularFactor > 0) -> if(SpecularFactor > 0.0)