c – 正常映射和翻译会破坏我的照明

我有一个正常的映射问题.我在通过ASSIMP库加载的每个模型上都有纹理和普通纹理.我在ASSIMP库的帮助下计算每个对象的切向量,所以这些应该没问题.这些对象与法线贴图完美配合,但是一旦我开始平移其中一个对象(从而影响具有平移的模型矩阵),灯光就会失败.正如你在图像上看到的那样,地板(沿着y轴向下平移)似乎失去了大部分漫射光,而且它的镜面光线方向错误(应该在灯泡和播放器位置之间)

它可能与普通矩阵有关(尽管翻译应该丢失),也许在着色器中使用了错误的矩阵.我没有想法,希望你能对这个问题有所了解.

顶点着色器：

#version 330

layout(location = 0) in vec3 position;
layout(location = 1) in vec3 normal;
layout(location = 2) in vec3 tangent;
layout(location = 3) in vec3 color;
layout(location = 4) in vec2 texCoord;

// fragment pass through
out vec3 Position;
out vec3 normal;
out vec3 Tangent;
out vec3 Color;
out vec2 TexCoord;

out vec3 TangentSurface2Light;
out vec3 TangentSurface2View;

uniform vec3 lightPos;
uniform vec3 playerPos;

// vertex transformation
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

void main()
{
    mat3 normalMatrix = mat3(transpose(inverse(model))); 
    Position = vec3(model * vec4(position,1.0)); 
    normal = normalMatrix * normal;
    Tangent = tangent;
    Color = color;
    TexCoord = texCoord;

    gl_Position = projection * view * model * vec4(position,1.0);

    // Calculate tangent matrix and calculate fragment bump mapping coord space.
    vec3 light = lightPos;
    vec3 n = normalize(normalMatrix * normal);
    vec3 t = normalize(normalMatrix * tangent);
    vec3 b = cross(n,t);
    // create matrix for tangent (from vertex to tangent-space)
    mat3 mat = mat3(t.x,b.x,n.x,t.y,b.y,n.y,t.z,b.z,n.z);
    vec3 vector = normalize(light - Position);
    TangentSurface2Light = mat * vector;
    vector = normalize(playerPos - Position);
    TangentSurface2View = mat * vector;
}

片段着色器

#version 330

in vec3 Position;
in vec3 normal;
in vec3 Tangent;
in vec3 Color;
in vec2 TexCoord;

in vec3 TangentSurface2Light;
in vec3 TangentSurface2View;

out vec4 outColor;

uniform vec3 lightPos;
uniform vec3 playerPos;
uniform mat4 view;
uniform sampler2D texture0;
uniform sampler2D texture_normal; // normal

uniform float repeatFactor = 1;

void main()
{   
    vec4 texColor = texture(texture0,TexCoord * repeatFactor);
    vec4 matColor = vec4(Color,1.0);
    vec3 light = vec3(vec4(lightPos,1.0));
    float dist = length(light - Position);
    // float att = 1.0 / (1.0 + 0.01 * dist + 0.001 * dist * dist);
    float att = 1.0;
    // Ambient
    vec4 ambient = vec4(0.2);
    // Diffuse
    // vec3 surface2light = normalize(light - Position);
    vec3 surface2light = normalize(TangentSurface2Light);
    // vec3 norm = normalize(normal); 
    vec3 norm = normalize(texture(texture_normal,TexCoord * repeatFactor).xyz * 2.0 - 1.0); 
    float contribution = max(dot(norm,surface2light),0.0);
    vec4 diffuse = contribution * vec4(0.6);
    // specular
    // vec3 surf2view = normalize(-Position); // Player is always at position 0
    vec3 surf2view = normalize(TangentSurface2View);
    vec3 reflection = reflect(-surface2light,norm); // reflection vector
    float specContribution = pow(max(dot(surf2view,reflection),0.0),32);
    vec4 specular = vec4(1.0) * specContribution;

    outColor = (ambient + (diffuse * att)+ (specular * pow(att,3))) * texColor;
    // outColor = vec4(Color,1.0) * texture(texture0,TexCoord);
}

编辑

编辑着色器代码来计算世界空间中的所有内容,而不是在世界和相机空间之间进行乒乓球(更容易理解,更不容易出错).

void main_vs(in A2V input,out V2P output) 
{
    output.position = mul(input.position,_worldViewProjection);
    output.normal = input.normal;
    output.binormal = input.binormal;
    output.tangent = input.tangent;
    output.positionWorld = mul(input.position,_world);
    output.tex = input.tex;
}

void main_ps(in V2P input,out float4 output : SV_Target)
{
    float3x3 tbn = float3x3(input.tangent,-input.binormal,input.normal);

    //extract & decode normal:
    float3 texnormal = _normalTexture.Sample(_normalSampler,input.tex).xyz * 2 - 1;

    //Now transform TBN-space texnormal to world space:
    float3 normal = mul(texnormal,tbn);
    normal = normalize(mul(normal,_world));

    float3 lightDirection = -_lightPosition.xyz;//directional
    float3 viewDirection = normalize(input.positionWorld - _camera);
    float3 reflectedLight = reflect(lightDirection,normal);

    float diffuseIntensity = dot(normal,lightDirection);
    float specularIntensity = max(0,dot(reflectedLight,viewDirection)*1.3);

    output = ((_ambient + diffuseIntensity * _diffuse) * _texture.Sample(_sampler,input.tex) 
        + pow(specularIntensity,7) * float4(1,1,1)) * _lightColor;
}

float3 lightDirection = normalize(input.positionWorld - _lightPosition.xyz);//omni

cbuffer ViewTranforms
{
    row_major matrix _worldViewProjection;
    row_major matrix _world;
    float3 _camera;
};

cbuffer BumpData
{
    float4 _ambient;
    float4 _diffuse;
};

cbuffer Textures
{
    texture2D _texture;
    SamplerState _sampler;

    texture2D _normalTexture;
    SamplerState _normalSampler;
};

cbuffer Light
{
    float4 _lightPosition;
    float4 _lightColor;
};

//------------------------------------

struct A2V
{
    float4 position : POSITION;
    float3 normal : norMAL;
    float3 binormal : BInorMAL;
    float3 tangent : TANGENT;
    float2 tex : TEXCOORD;
};

struct V2P
{
    float4 position : SV_POSITION;
    float3 normal : norMAL;
    float3 binormal : BInorMAL;
    float3 tangent : TANGENT;
    float3 positionWorld : norMAL1;
    float2 tex : TEXCOORD;
};