我有一个透明部分的纹理，而不是被渲染为透明，他们是黑色的。

为了测试RGBA值是否正确传递到着色器，我让所有的东西都以灰度渲染。我认为alpha值没有正确传递。

不管怎样，这里是纹理加载的方式：

@classmethod
    def load_texture(cls, file_name: str):
        try:
            img = Image.open(f"{sys.path[0]}/res/{file_name}.png").convert('RGBA')
            img = img.transpose(Image.FLIP_TOP_BOTTOM)  # flip image upside down
        except Exception as e:
            print(e)
            img = Image.open(f"{sys.path[0]}/res/missing_texture.png").convert('RGBA')
            img = img.transpose(Image.FLIP_TOP_BOTTOM)  # flip image upside down

        ix, iy, image = img.size[0], img.size[1], img.tobytes("raw", "RGBA", 0, -1)

        texture_id = glGenTextures(1)             # generate a texture ID
        cls.__textures.append(texture_id)
        glBindTexture(GL_TEXTURE_2D, texture_id)  # make it current
        # copy the texture into the current texture texture_id
        glTexImage2D(GL_TEXTURE_2D, 0, 3, ix, iy, 0, GL_RGBA, GL_UNSIGNED_BYTE, image)

        glPixelStorei(GL_UNPACK_ALIGNMENT, 1)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)

        return texture_id

这是我的片段着色器（注解掉的部分显然不起作用）：

#version 400 core

in vec2 pass_texture_coords;
in vec3 surface_normal;
in vec3 to_light_vector;
in vec3 to_camera_vector;

out vec4 out_color;

uniform sampler2D model_texture;
uniform vec3 light_color;
uniform float shine_damper;
uniform float reflectivity;

void main(void){
    vec4 texture_color = texture(model_texture, pass_texture_coords);
    texture_color = vec4(vec3(texture_color.a), 1.0);
    //if(texture_color.a < 0.5){
    //    discard;
    //}

    vec3 unit_normal = normalize(surface_normal);
    vec3 unit_light_vector = normalize(to_light_vector);

    float n_dot1 = dot(unit_normal, unit_light_vector);
    float brightness = max(n_dot1, 0.1);
    vec3 diffuse = brightness * light_color;

    vec3 unit_vector_to_camera = normalize(to_camera_vector);
    vec3 light_direction = -unit_light_vector;
    vec3 reflected_light_direction = reflect(light_direction, unit_normal);

    float specular_factor = dot(reflected_light_direction, unit_vector_to_camera);
    specular_factor = max(specular_factor, 0.0);
    float damped_factor = pow(specular_factor, shine_damper);
    vec3 final_specular = damped_factor * reflectivity * light_color;

    out_color = vec4(diffuse, 1.0) * texture_color + vec4(final_specular, 1.0);

}

同样在渲染任何内容之前，调用此方法：

@staticmethod
    def update_display():
        InputController().apply_input()                     # apply inputs every frame

        glEnable(GL_BLEND)
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)   # so that transparent bits of the texture won't get rendered
        glEnable(GL_ALPHA_TEST)

        glEnable(GL_DEPTH_TEST)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)  # Remove everything from screen (i.e. displays all white)
        glClearColor(0, 0.3, 0, 1)                          # set backdrop color
        glLoadIdentity()                                    # Reset all graphic/shape's position