在GLSL中混合多个纹理

uniform sampler2D texture1;
uniform sampler2D texture2;
uniform float blendFactor;

void main() {
    vec4 color1 = texture2D(texture1, vUv);
    vec4 color2 = texture2D(texture2, vUv);
    gl_FragColor = mix(color1, color2, blendFactor);
}

uniform sampler2D texture1;
uniform sampler2D texture2;

void main() {
    vec4 color1 = texture2D(texture1, vUv);
    vec4 color2 = texture2D(texture2, vUv);
    gl_FragColor = color1 + color2;
}

uniform sampler2D diffuseTexture;
uniform sampler2D specularTexture;
uniform sampler2D normalTexture;

void main() {
    vec4 diffuseColor = texture2D(diffuseTexture, vUv);
    vec4 specularColor = texture2D(specularTexture, vUv);
    vec4 normalColor = texture2D(normalTexture, vUv);

    // 应用纹理到相应的材质通道
    // ...
}