OpenGL光线六 opengl多光源 MultipleLights

一、定义短多个光源
//平行光
LightDirectional lightD(glm::vec3(10.0f, 10.0f, -5.0f), glm::vec3(glm::radians(90.0f), glm::radians(0.0f), 0));
//点光源
LightPoint lightP0(glm::vec3(1.0f, .0f, .0f), glm::vec3(glm::radians(45.0f), glm::radians(45.0f), 0), glm::vec3(1.0f, 0.0f, 0.0f));
LightPoint lightP1(glm::vec3(.0f, 1.0f, .0f), glm::vec3(glm::radians(45.0f), glm::radians(45.0f), 0), glm::vec3(0.0f, 1.0f, 0.0f));
LightPoint lightP2(glm::vec3(.0f, .0f, 1.0f), glm::vec3(glm::radians(45.0f), glm::radians(45.0f), 0), glm::vec3(0.0f, 0.0f, 10.0f));
LightPoint lightP3(glm::vec3(1.0f, 3.0f, -.0f), glm::vec3(glm::radians(45.0f), glm::radians(45.0f), 0), glm::vec3(1.0f, 1.0f, 1.0f));
//聚光灯
LightSpot lightS(glm::vec3(0.0f, 5.0f, 0.0f), glm::vec3(glm::radians(90.0f), 0, 0), glm::vec3(1.0f, 1.0f, 1.0f));

二、通过uniform传递光源信息
//平行光
glUniform3f(glGetUniformLocation(pshader->ID, “lightD.color”), lightD.color.r, lightD.color.g, lightD.color.b);
glUniform3f(glGetUniformLocation(pshader->ID, “lightD.dirToLight”), lightD.direction.x, lightD.direction.y, lightD.direction.z);
//点光源0
glUniform3f(glGetUniformLocation(pshader->ID, “lightP[0].pos”), lightP0.postion.x, lightP0.postion.y, lightP0.postion.z);
glUniform3f(glGetUniformLocation(pshader->ID, “lightP[0].color”), lightP0.color.r, lightP0.color.g, lightP0.color.b);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[0].constant”), lightP0.constant);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[0].linear”), lightP0.linear);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[0].quadratic”), lightP0.quadratic);
//点光源1
glUniform3f(glGetUniformLocation(pshader->ID, “lightP[1].pos”), lightP1.postion.x, lightP1.postion.y, lightP1.postion.z);
glUniform3f(glGetUniformLocation(pshader->ID, “lightP[1].color”), lightP1.color.r, lightP1.color.g, lightP1.color.b);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[1].constant”), lightP1.constant);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[1].linear”), lightP1.linear);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[1].quadratic”), lightP1.quadratic);
//点光源2
glUniform3f(glGetUniformLocation(pshader->ID, “lightP[2].pos”), lightP2.postion.x, lightP2.postion.y, lightP2.postion.z);
glUniform3f(glGetUniformLocation(pshader->ID, “lightP[2].color”), lightP2.color.r, lightP2.color.g, lightP2.color.b);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[2].constant”), lightP2.constant);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[2].linear”), lightP2.linear);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[2].quadratic”), lightP2.quadratic);
//点光源3
glUniform3f(glGetUniformLocation(pshader->ID, “lightP[3].pos”), lightP3.postion.x, lightP3.postion.y, lightP3.postion.z);
glUniform3f(glGetUniformLocation(pshader->ID, “lightP[3].color”), lightP3.color.r, lightP3.color.g, lightP3.color.b);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[3].constant”), lightP3.constant);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[3].linear”), lightP3.linear);
glUniform1f(glGetUniformLocation(pshader->ID, “lightP[3].quadratic”), lightP3.quadratic);
//聚光灯
glUniform3f(glGetUniformLocation(pshader->ID, “lightS.pos”), lightS.postion.x, lightS.postion.y, lightS.postion.z);
glUniform3f(glGetUniformLocation(pshader->ID, “lightS.color”), lightS.color.r, lightS.color.g, lightS.color.b);
glUniform3f(glGetUniformLocation(pshader->ID, “lightS.dirToLight”), lightS.direction.x, lightS.direction.y, lightS.direction.z);
glUniform1f(glGetUniformLocation(pshader->ID, “lightS.constant”), lightS.constant);
glUniform1f(glGetUniformLocation(pshader->ID, “lightS.linear”), lightS.linear);
glUniform1f(glGetUniformLocation(pshader->ID, “lightS.quadratic”), lightS.quadratic);
glUniform1f(glGetUniformLocation(pshader->ID, “lightS.cosPhyInner”), lightS.cosPhyInner);
glUniform1f(glGetUniformLocation(pshader->ID, “lightS.cosPhyOutter”), lightS.cosPhyOutter);

三、在fragmentShader中计算不同光源，并求和
1、光照模型
//////////////光照模型//////////////////////
vec3 lightingMode(Material material,vec3 lightColor,vec3 lightDir,vec3 uNormal,vec3 dirToCamera, bool glow){
vec3 resultColor;
//specular
vec3 reflectVec =reflect(lightDir,uNormal);
float specularAmount = pow(max(dot(reflectVec,dirToCamera),0.0f),material.shininess);
vec3 specular = texture(material.specular,TextCoord).rgbspecularAmountlightColor;

//deffuse
float diffuseAmount = max(dot(lightDir,uNormal),0.0f);
vec3 diffuse = texture(material.diffuse,TextCoord).rgb* diffuseAmount*lightColor;

//ambient
vec3 ambient = texture(material.diffuse,TextCoord).rgb*ambientColor;
ambient = ambient/2+ambient*(specularAmount+diffuseAmount);
//vec3 ambient = texture(material.diffuse,TextCoord).rgb*ambientColor*(specularAmount+diffuseAmount);

//emission
vec3 emission=vec3(0,0,0);
if(glow){
	emission = texture(material.emission,TextCoord).rgb;
}
return resultColor = ambient+diffuse+specular+emission;

}
2、计算三种不同的光源
//计算平行光
vec3 CalcLightDirectional(LightDirectional light,vec3 uNormal,vec3 dirToCamera){
return lightingMode(material,light.color,light.dirToLight,uNormal,dirToCamera,false);
}
//计算点光源
vec3 CalcLightPoint(LightPoint light,vec3 uNormal,vec3 dirToCamera){
vec3 resultColor=vec3(0,0,0);
//attenuation衰减系数
float dist = length(light.pos-FragPos);
float attenuation = 1/(light.constant+light.lineardist+light.quadraticdistdist);
resultColor = light.colorattenuation;
vec3 lightDir = normalize(light.pos-FragPos);
return lightingMode(material,resultColor,lightDir,uNormal,dirToCamera,false);
}
//计算聚光灯
vec3 CalcLightSpot(LightSpot light,vec3 uNormal,vec3 dirToCamera){
vec3 resultColor=vec3(0,0,0);
//attenuation衰减系数
float dist = length(light.pos-FragPos);
float attenuation = 1/(light.constant+light.lineardist+light.quadraticdist*dist);

float cosTheta = dot(normalize(FragPos - light.pos),-1*light.dirToLight);
float spotRatio = (cosTheta-light.cosPhyOutter)/(light.cosPhyInner-light.cosPhyOutter);
if(cosTheta>light.cosPhyInner){
	//inside
	resultColor = light.color*attenuation;
}else if(cosTheta>light.cosPhyOutter){
	//middle
	resultColor = light.color*spotRatio*attenuation;
}else{
	//outside
	resultColor = light.color*0.0f;
}
vec3 lightDir = normalize(light.pos-FragPos);
return lightingMode(material,resultColor,lightDir,uNormal,dirToCamera,false);

}
3、将计算的结果叠加
vec3 finalColor=vec3(0,0,0);
//1、LightDirection 平行光
vec3 uNormal=normalize(Normal);
vec3 dirToCamera=normalize(cameraPos-FragPos);
finalColor += CalcLightDirectional(lightD,uNormal,dirToCamera);
//2、LightPoint 点光源
for(int i=0;i<4;i++){
finalColor += CalcLightPoint(lightP[i],uNormal,dirToCamera);
}
//3、LightSpot 聚光灯
finalColor += CalcLightSpot(lightS,uNormal,dirToCamera);

FragColor = vec4(finalColor,1.0f);

代码Git地址.