C++ 用于2点光源的learnopengl教程片段着色器

我一直在遵循教程，并尝试使用所描述的方法加载模型。它一直工作到最后，要求你在纳米电路上加载2个点光源。我从教程中复制了完整的代码：摄影机、网格、模型和着色器类，但问题在于片段着色器。如果我尝试一个简单的方法，如：

#version 330 core

in vec2 TexCoords;

out vec4 color;

uniform sampler2D texture_diffuse1;

void main()
{    
    color = vec4(texture(texture_diffuse1, TexCoords));
}

，将加载模型和纹理。但如果尝试为2点照明提供的解决方案，纹理为黑色：

#version 330 core
struct Material {
    sampler2D texture_diffuse1;
    sampler2D texture_specular1;
    float shininess;
}; 
/* Note: because we now use a material struct again you want to change your
mesh class to bind all the textures using material.texture_diffuseN instead of
texture_diffuseN. */

struct PointLight {
    vec3 position;

    float constant;
    float linear;
    float quadratic;

    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
};

#define NR_POINT_LIGHTS 2

in vec3 fragPosition;
in vec3 Normal;
in vec2 TexCoords;

out vec4 color;

uniform vec3 viewPos;
uniform PointLight pointLights[NR_POINT_LIGHTS];
uniform Material material;

// Function prototypes
vec3 CalcPointLight(PointLight light, Material mat, vec3 normal, vec3 fragPos, vec3 viewDir);

void main()
{    
    vec3 result;
    vec3 viewDir = normalize(viewPos - fragPosition);
    vec3 norm = normalize(Normal);

    for(int i = 0; i < NR_POINT_LIGHTS; i++)
        result += CalcPointLight(pointLights[i], material, norm, fragPosition, viewDir);

    color = vec4(result, 1.0f);
}


// Calculates the color when using a point light.
vec3 CalcPointLight(PointLight light, Material mat, vec3 normal, vec3 fragPos, vec3 viewDir)
{
    vec3 lightDir = normalize(light.position - fragPos);
    // Diffuse shading
    float diff = max(dot(normal, lightDir), 0.0);
    // Specular shading
    vec3 reflectDir = reflect(-lightDir, normal);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), mat.shininess);
    // Attenuation
    float distance = length(light.position - fragPos);
    float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));    
    // Combine results
    vec3 ambient = light.ambient * vec3(texture(mat.texture_diffuse1, TexCoords));
    vec3 diffuse = light.diffuse * diff * vec3(texture(mat.texture_diffuse1, TexCoords));
    vec3 specular = light.specular * spec * vec3(texture(mat.texture_specular1, TexCoords));
    ambient *= attenuation;
    diffuse *= attenuation;
    specular *= attenuation;
    return (ambient + diffuse + specular);
}

致：

---

有人有相同的问题吗？

似乎GLSL不喜欢功能。如果我使用CalcPointLight（）代码并将其放在main（）中，它就会工作

#version 330 core
struct Material {
    sampler2D texture_diffuse1;
    sampler2D texture_specular1;
    float shininess;
};
/* Note: because we now use a material struct again you want to change your
mesh class to bind all the textures using material.texture_diffuseN instead of
texture_diffuseN. */

struct PointLight {
    vec3 position;

    float constant;
    float linear;
    float quadratic;

    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
};

#define NR_POINT_LIGHTS 2

in vec3 fragPosition;
in vec3 Normal;
in vec2 TexCoords;

out vec4 color;

uniform vec3 viewPos;
uniform PointLight pointLights[NR_POINT_LIGHTS];
uniform Material material;

void main()
{
    vec3 result;
    vec3 viewDir = normalize(viewPos - fragPosition);
    vec3 norm = normalize(Normal);

    vec3 lightDir = normalize(pointLights[0].position - fragPosition);

    // Diffuse shading
    float diff = max(dot(norm, lightDir), 0.0);

    // Specular shading
    vec3 reflectDir = reflect(-lightDir, norm);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);

    // Attenuation
    float distance = length(pointLights[0].position - fragPosition);
    float attenuation = 1.0f / (pointLights[0].constant + pointLights[0].linear * distance + pointLights[0].quadratic * (distance * distance));

    // Combine results
    vec3 ambient = pointLights[0].ambient * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 diffuse = pointLights[0].diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 specular = pointLights[0].specular * spec * vec3(texture(material.texture_specular1, TexCoords));
    ambient *= attenuation;
    diffuse *= attenuation;
    specular *= attenuation;
    result = ambient+diffuse+specular;

    color = vec4(result, 1.0f);
}

编辑：在那里找到了答案：。不能实例化包含不透明类型（如sampler2D）的结构

Edit1:您可以将这些变量实际用于函数中，而无需将它们作为参数传递，因为它们是全局定义的：

#version 330 core
struct Material {
    sampler2D texture_diffuse1;
    sampler2D texture_specular1;
    float shininess;
};
/* Note: because we now use a material struct again you want to change your
mesh class to bind all the textures using material.texture_diffuseN instead of
texture_diffuseN. */

struct PointLight {
    vec3 position;

    float constant;
    float linear;
    float quadratic;

    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
};

#define NR_POINT_LIGHTS 2

in vec3 fragPosition;
in vec3 Normal;
in vec2 TexCoords;

out vec4 color;

uniform vec3 viewPos;
uniform PointLight pointLights[NR_POINT_LIGHTS];
uniform Material material;

vec3 CalcLights(int i);

void main()
{
    vec3 result;
    for(int i=0; i<NR_POINT_LIGHTS; i++)
        result += CalcLights(i);
    color = vec4(result, 1.0f);
}

vec3 CalcLights(int i) //viewPos fragPosition pointLights[] Normal material TexCoords
{
    vec3 viewDir = normalize(viewPos - fragPosition);
    vec3 norm = normalize(Normal);

    vec3 lightDir = normalize(pointLights[i].position - fragPosition);

    // Diffuse shading
    float diff = max(dot(norm, lightDir), 0.0);

    // Specular shading
    vec3 reflectDir = reflect(-lightDir, norm);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);

    // Attenuation
    float distance = length(pointLights[i].position - fragPosition);
    float attenuation = 1.0f / (pointLights[i].constant + pointLights[i].linear * distance + pointLights[i].quadratic * (distance * distance));

    // Combine results
    vec3 ambient = pointLights[0].ambient * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 diffuse = pointLights[0].diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 specular = pointLights[0].specular * spec * vec3(texture(material.texture_specular1, TexCoords));
    ambient *= attenuation;
    diffuse *= attenuation;
    specular *= attenuation;

    return (ambient+diffuse+specular);
}

#版本330核心
结构材料{
采样2D纹理_扩散1；
取样器2D纹理_镜面1；
浮光；
};
/*注意：由于我们现在再次使用材质结构，您希望更改
网格类使用material.texture\u diffuseN而不是
纹理扩散*/
结构点光源{
vec3位置；
浮动常数；
浮动线性；
浮动二次型；
vec3环境；
vec3弥漫性；
vec3镜面反射；
};
#定义NR_点_灯2
在vec3帧位置；
vec3正常；
在vec2-TexCoords中；
输出vec4颜色；
统一的vec3视图位置；
统一点光源点光源[NR_点光源]；
均匀的材料；
vec3 CalcLights（int i）；
void main（）
{
vec3结果；
对于（int i=0；iWhy the downvote？一个解释会很有用。您是否查看了着色器编译错误？我没有任何错误。它编译很好，但运行时显示黑色纹理。除了main之外，是否无法从其他函数访问制服？
#version 330 core
struct Material {
    sampler2D texture_diffuse1;
    sampler2D texture_specular1;
    float shininess;
};
/* Note: because we now use a material struct again you want to change your
mesh class to bind all the textures using material.texture_diffuseN instead of
texture_diffuseN. */

struct PointLight {
    vec3 position;

    float constant;
    float linear;
    float quadratic;

    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
};

#define NR_POINT_LIGHTS 2

in vec3 fragPosition;
in vec3 Normal;
in vec2 TexCoords;

out vec4 color;

uniform vec3 viewPos;
uniform PointLight pointLights[NR_POINT_LIGHTS];
uniform Material material;

void main()
{
    vec3 result;
    vec3 viewDir = normalize(viewPos - fragPosition);
    vec3 norm = normalize(Normal);

    vec3 lightDir = normalize(pointLights[0].position - fragPosition);

    // Diffuse shading
    float diff = max(dot(norm, lightDir), 0.0);

    // Specular shading
    vec3 reflectDir = reflect(-lightDir, norm);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);

    // Attenuation
    float distance = length(pointLights[0].position - fragPosition);
    float attenuation = 1.0f / (pointLights[0].constant + pointLights[0].linear * distance + pointLights[0].quadratic * (distance * distance));

    // Combine results
    vec3 ambient = pointLights[0].ambient * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 diffuse = pointLights[0].diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 specular = pointLights[0].specular * spec * vec3(texture(material.texture_specular1, TexCoords));
    ambient *= attenuation;
    diffuse *= attenuation;
    specular *= attenuation;
    result = ambient+diffuse+specular;

    color = vec4(result, 1.0f);
}

#version 330 core
struct Material {
    sampler2D texture_diffuse1;
    sampler2D texture_specular1;
    float shininess;
};
/* Note: because we now use a material struct again you want to change your
mesh class to bind all the textures using material.texture_diffuseN instead of
texture_diffuseN. */

struct PointLight {
    vec3 position;

    float constant;
    float linear;
    float quadratic;

    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
};

#define NR_POINT_LIGHTS 2

in vec3 fragPosition;
in vec3 Normal;
in vec2 TexCoords;

out vec4 color;

uniform vec3 viewPos;
uniform PointLight pointLights[NR_POINT_LIGHTS];
uniform Material material;

vec3 CalcLights(int i);

void main()
{
    vec3 result;
    for(int i=0; i<NR_POINT_LIGHTS; i++)
        result += CalcLights(i);
    color = vec4(result, 1.0f);
}

vec3 CalcLights(int i) //viewPos fragPosition pointLights[] Normal material TexCoords
{
    vec3 viewDir = normalize(viewPos - fragPosition);
    vec3 norm = normalize(Normal);

    vec3 lightDir = normalize(pointLights[i].position - fragPosition);

    // Diffuse shading
    float diff = max(dot(norm, lightDir), 0.0);

    // Specular shading
    vec3 reflectDir = reflect(-lightDir, norm);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);

    // Attenuation
    float distance = length(pointLights[i].position - fragPosition);
    float attenuation = 1.0f / (pointLights[i].constant + pointLights[i].linear * distance + pointLights[i].quadratic * (distance * distance));

    // Combine results
    vec3 ambient = pointLights[0].ambient * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 diffuse = pointLights[0].diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 specular = pointLights[0].specular * spec * vec3(texture(material.texture_specular1, TexCoords));
    ambient *= attenuation;
    diffuse *= attenuation;
    specular *= attenuation;

    return (ambient+diffuse+specular);
}