python - 使用 PyOpenGL 和 PyQt5 转换对象时出错

Question

我正在尝试使用矢量着色器转换对象。但 glUniformMatrixfv 在执行时会引发错误。

vertex_shader = shaders.compileShader(
                """
                #version 330
                layout (location = 0) in vec3 pos;
                layout (location = 1) in vec3 color;
                uniform mat4 movement;
                out vec4 f_color;
                void main() 
                { 
                    gl_Position = movement * vec4(pos, 1.0);
                    f_color = vec4(color, 1.0);
                }
                """
                , GL_VERTEX_SHADER)


fragment_shader = shaders.compileShader(
                """
                #version 330
                in vec4 f_color;
                out vec4 gl_FragColor;
                void main() 
                {
                    gl_FragColor = f_color;
                }
                """
                , GL_FRAGMENT_SHADER
                )

使用这些着色器的程序代码是:

def draw_object(self):
    self.vao = glGenVertexArrays(1)
    glBindVertexArray(self.vao)

    self.vbo_buffer = np.array([
        -0.4, 0.2, 0.0, 0.0, 1.0, 0.0,
        -0.8, -0.2, 0.0, 1.0, 1.0, 0.0,
        0.0, -0.2, 0.0, 0.0, 1.0, 1.0,
        0.2, -0.4, 0.0, 1.0, 0.0, 0.0,
        0.8, -0.4, 0.0, 0.0, 0.0, 1.0,
        0.8, 0.4, 0.0, 0.0, 1.0, 1.0,
        0.2, -0.4, 0.0, 1.0, 0.0, 0.0,
        0.8, 0.4, 0.0, 0.0, 0.0, 1.0,
        0.2, 0.4, 0.0, 0.0, 1.0, 0.0
    ], dtype=np.float32)

    self.vbo = glGenBuffers(1)
    glBindBuffer(GL_ARRAY_BUFFER, self.vbo)
    glBufferData(GL_ARRAY_BUFFER, self.vbo_buffer.nbytes, self.vbo_buffer, GL_DYNAMIC_DRAW)

    self.vertex_position = glGetAttribLocation(self.shader, bytestr('pos'))
    glVertexAttribPointer(self.vertex_position, 3, GL_FLOAT, GL_FALSE, 24, None)
    glEnableVertexAttribArray(self.vertex_position)

    self.vertex_color = glGetAttribLocation(self.shader, bytestr('color'))
    glVertexAttribPointer(self.vertex_color, 3, GL_FLOAT, GL_FALSE, 24, ctypes.c_void_p(12))
    glEnableVertexAttribArray(self.vertex_color)

    self.movement = glGetUniformLocation(self.shader, 'movement')
    glUniformMatrix4fv(self.movement, 1, GL_FALSE, glm.value_ptr(self.svp_matrix))

    glBindBuffer(GL_ARRAY_BUFFER, 0)
    glBindVertexArray(0)


def calculate_mvp(self):
    self.projection_matrix = glm.perspective(glm.radians(self.fieldOfView), self.glWinWidth / self.glWinHeight, 
                             self.nearPlane, self.farPlane)
    self.view_matrix = glm.rotate(glm.mat4(1.0), float(self.xRot), glm.vec3(1.0, 0.0, 0.0)) * \
                       glm.rotate(glm.mat4(1.0), float(self.yRot), glm.vec3(0.0, 1.0, 0.0)) * \
                       glm.rotate(glm.mat4(1.0), float(self.zRot), glm.vec3(0.0, 0.0, 1.0)) * \
                       glm.translate(glm.mat4(1.0), glm.vec3(self.xTranslate, self.yTranslate, self.zTranslate))
    self.scale_matrix = glm.scale(glm.mat4(1.0), glm.vec3(self.scale_factor))

    self.svp_matrix = self.projection_matrix * self.view_matrix * self.scale_matrix


def paintGL(self):
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glUseProgram(self.shader)
    try:
        glBindVertexArray(self.vao)
        glDrawArrays(GL_TRIANGLES, 0, 9) 
    finally:
        glBindVertexArray(0)
        glUseProgram(0)
        glFlush()

我得到的错误是:

File "C:\Program Files\Python37\lib\site-packages\OpenGL\platform\baseplatform.py", line 415, in __call__

return self( *args, **named )

File "src\errorchecker.pyx", line 58, in OpenGL_accelerate.errorchecker._ErrorChecker.glCheckError OpenGL.error.GLError: GLError(

   err = 1282,
   description = b'invalid operation',
   baseOperation = glUniformMatrix4fv,
   pyArgs = (
           0,
           1,
           GL_FALSE,
           <OpenGL.GLU.tess.LP_c_float object at 0x0000013A37B1B4C8>,
   ),
   cArgs = (
           0,
           1,
           GL_FALSE,
           <OpenGL.GLU.tess.LP_c_float object at 0x0000013A37B1B4C8>,
   ),
   cArguments = (
           0,
           1,
           GL_FALSE,
           <OpenGL.GLU.tess.LP_c_float object at 0x0000013A37B1B4C8>,
   )

)

如果您知道如何解决此问题，请在下面分享。谢谢

Answer 1

glUniformMatrix4fv设置当前安装程序的默认统一 block 中统一变量的值。
这意味着该程序必须通过 glUseProgram 安装，然后才能设置变量。如果没有当前程序对象，则会生成 GL_INVALID_OPERATION 错误。

在glUniformMatrix4fv之前安装程序:

self.movement = glGetUniformLocation(self.shader, 'movement')

glUseProgram(self.shader)
glUniformMatrix4fv(self.movement, 1, GL_FALSE, glm.value_ptr(self.svp_matrix))