问OpenGl C++如何用骨骼动画实现三维模型的照明

EN

#version 330 core

layout(location = 0) in vec3 pos;
layout(location = 1) in vec3 norm;
layout(location = 2) in vec2 tex;
layout(location = 5) in ivec4 boneIds;
layout(location = 6) in vec4 weights;
    
uniform mat4 projection;
uniform mat4 view;
uniform mat4 model;
    
const int MAX_BONES = 100;
const int MAX_BONE_INFLUENCE = 4;
uniform mat4 finalBonesMatrices[MAX_BONES];
    
out vec2 TexCoords;
out vec3 FragPos;
out vec3 Normal;
    
void main()
{
    vec4 totalPosition = vec4(0.0f);
    for(int i = 0 ; i < MAX_BONE_INFLUENCE ; i++)
    {
        if(boneIds[i] == -1)
            continue;
        if(boneIds[i] >=MAX_BONES)
        {
            totalPosition = vec4(pos,1.0f);
            break;
        }
        vec4 localPosition = (finalBonesMatrices[boneIds[i]] * weights[i]) * vec4(pos,1.0f);
        totalPosition += localPosition;
        vec3 localNormal =mat3(transpose(inverse(finalBonesMatrices[boneIds[i]]))) * norm;
    }
    mat4 viewModel = view * model;
    gl_Position =  projection * viewModel * totalPosition;
    TexCoords = tex;
    FragPos = pos;
    Normal = norm;
}

#version 330 core
out vec4 FragColor;

struct Material {
    sampler2D texture_diffuse1;
    sampler2D texture_specular1;
    float shininess;
};

struct DirLight {
    vec3 direction;
    
    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
    float intensityVal;
};

struct PointLight {
    vec3 position;
    
    float constant;
    float linear;
    float quadratic;
    
    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
    float intensityVal;
};

struct SpotLight {
    vec3 position;
    vec3 direction;
    float cutOff;
    float outerCutOff;
  
    float constant;
    float linear;
    float quadratic;
  
    vec3 ambient;
    vec3 diffuse;
    vec3 specular;
    float intensityVal;
};

#define MAX_POINT_LIGHTS 1
#define MAX_SPOT_LIGHTS 1
#define MAX_DIR_LIGHTS 1

in vec3 FragPos;
in vec3 Normal;
in vec2 TexCoords;

uniform vec3 viewPos;
uniform DirLight dirLight[MAX_DIR_LIGHTS];
uniform PointLight pointLights[MAX_POINT_LIGHTS];
uniform SpotLight spotLight[MAX_SPOT_LIGHTS];
uniform Material material;

// function prototypes
vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir);
vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir);

void main()
{
    // properties
    vec3 norm = normalize(Normal);
    vec3 viewDir = normalize(viewPos - FragPos);
    vec3 result=vec3(0.0);
    


    // directional lighting
    for(int i = 0; i < MAX_DIR_LIGHTS; i++)
        result += CalcDirLight(dirLight[i], norm, viewDir);
    //point lights
    for(int i = 0; i < MAX_POINT_LIGHTS; i++)
        result += CalcPointLight(pointLights[i], norm, FragPos, viewDir);
    // spot light
    for(int i = 0; i < MAX_SPOT_LIGHTS; i++)
        result += CalcSpotLight(spotLight[i], norm, FragPos, viewDir);
    
    FragColor = vec4(result, 1.0);
}

// calculates the color when using a directional light.
vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir)
{
    vec3 lightDir = normalize(-light.direction);
    // 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), material.shininess);
    // combine results
    vec3 ambient = light.ambient * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 diffuse = light.diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords))*light.intensityVal;
    vec3 specular = light.specular * spec * vec3(texture(material.texture_specular1, TexCoords))*light.intensityVal;
    return (ambient + diffuse + specular);
}

// calculates the color when using a point light.
vec3 CalcPointLight(PointLight light, 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), material.shininess);
    // attenuation
    float distance = length(light.position - fragPos);
    float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
    // combine results
    vec3 ambient = light.ambient * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 diffuse = light.diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords))*light.intensityVal;
    vec3 specular = light.specular * spec * vec3(texture(material.texture_specular1, TexCoords))*light.intensityVal;
    ambient *= attenuation;
    diffuse *= attenuation;
    specular *= attenuation;
    return (ambient + diffuse + specular);
}

// calculates the color when using a spot light.
vec3 CalcSpotLight(SpotLight light, 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), material.shininess);
    // attenuation
    float distance = length(light.position - fragPos);
    float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
    // spotlight intensity
    float theta = dot(lightDir, normalize(-light.direction));
    float epsilon = light.cutOff - light.outerCutOff;
    float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
    // combine results
    vec3 ambient = light.ambient * vec3(texture(material.texture_diffuse1, TexCoords));
    vec3 diffuse = light.diffuse * diff * vec3(texture(material.texture_diffuse1, TexCoords))*light.intensityVal;
    vec3 specular = light.specular * spec * vec3(texture(material.texture_specular1, TexCoords))*light.intensityVal;
    ambient *= attenuation * intensity;
    diffuse *= attenuation * intensity;
    specular *= attenuation * intensity;
    return (ambient + diffuse + specular);
}