python 中没有可见 window 的 OpenGL 渲染视图

Question

我需要渲染一些场景。我设法在 python 中使用 pyopengl 和 pygame 做到了这一点。问题是它会在短时间内创建 window。

我想渲染相同的图像并保存它，而不创建可见的 window（或者可能根本不创建 window，甚至不创建 pygame）。

import cv2
import numpy as np
import pygame
from pygame.locals import *
from OpenGL.GL import *
from OpenGL.GLU import *

def main():
    DISPLAY_WIDTH = 900
    DISPLAY_HEIGHT = 900

    pygame.init()
    pygame.display.set_mode((DISPLAY_WIDTH, DISPLAY_HEIGHT), DOUBLEBUF | OPENGL)
    gluPerspective(90, (DISPLAY_WIDTH / DISPLAY_HEIGHT), 0.01, 12)

    glEnable(GL_TEXTURE_2D)
    glEnable(GL_DEPTH_TEST)
    glDepthFunc(GL_LEQUAL)

    glRotatef(-90, 1, 0, 0) # Straight rotation
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glRotatef(285, 0, 0, 1) # Rotate yaw
    glTranslatef(-5, -3, -2) # Move to position

    # Draw rectangle
    glBegin(GL_QUADS)
    glColor3f(1, 0, 0)
    glVertex3f(2, 2, 0)
    glVertex3f(2, 2, 2)
    glVertex3f(2, 6, 2)
    glVertex3f(2, 6, 0)
    glEnd()

    image_buffer = glReadPixels(0, 0, DISPLAY_WIDTH, DISPLAY_HEIGHT, OpenGL.GL.GL_RGB, OpenGL.GL.GL_UNSIGNED_BYTE)
    image = np.frombuffer(image_buffer, dtype=np.uint8).reshape(DISPLAY_WIDTH, DISPLAY_HEIGHT, 3)

    cv2.imwrite(r"C:\temp\image.png", image)

    pygame.quit()


if __name__ == "__main__":
    main()

Answer 1

I want to render the same image and save it, without creating a visible window

如果没有任何 window.
，则无法创建 1.0 以上版本的 OpenGL Context 查看问题 Creating OpenGL context without window.

的答案

但是可以使用完全隐藏的window进行"offscreen"渲染。

遗憾的是，无法使用 Pygame.
创建最初隐藏的 window 只有在 pygame.display.iconify() 创建后才能隐藏 window。另见 Hiding pygame display.

但是可以创建一个最初隐藏的 window 与 GLFW library by setting the window hint VISIBLE 到 False.

可以在 glfw 1.7.0.

找到 glfw 库

代码可能如下所示：

import cv2
import numpy as np
from OpenGL.GL import *
from OpenGL.GLU import *
import glfw

def main():
    DISPLAY_WIDTH = 900
    DISPLAY_HEIGHT = 900

    # Initialize the library
    if not glfw.init():
        return
    # Set window hint NOT visible
    glfw.window_hint(glfw.VISIBLE, False)
    # Create a windowed mode window and its OpenGL context
    window = glfw.create_window(DISPLAY_WIDTH, DISPLAY_HEIGHT, "hidden window", None, None)
    if not window:
        glfw.terminate()
        return

    # Make the window's context current
    glfw.make_context_current(window)

    gluPerspective(90, (DISPLAY_WIDTH / DISPLAY_HEIGHT), 0.01, 12)

    glEnable(GL_TEXTURE_2D)
    glEnable(GL_DEPTH_TEST)
    glDepthFunc(GL_LEQUAL)

    glRotatef(-90, 1, 0, 0) # Straight rotation
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glRotatef(285, 0, 0, 1) # Rotate yaw
    glTranslatef(-5, -3, -2) # Move to position

    # Draw rectangle
    glBegin(GL_QUADS)
    glColor3f(1, 0, 0)
    glVertex3f(2, 2, 0)
    glVertex3f(2, 2, 2)
    glVertex3f(2, 6, 2)
    glVertex3f(2, 6, 0)
    glEnd()

    image_buffer = glReadPixels(0, 0, DISPLAY_WIDTH, DISPLAY_HEIGHT, OpenGL.GL.GL_RGB, OpenGL.GL.GL_UNSIGNED_BYTE)
    image = np.frombuffer(image_buffer, dtype=np.uint8).reshape(DISPLAY_WIDTH, DISPLAY_HEIGHT, 3)

    cv2.imwrite(r"C:\temp\image.png", image)

    glfw.destroy_window(window)
    glfw.terminate()

if __name__ == "__main__":
    main()

python 中没有可见 window 的 OpenGL 渲染视图

OpenGL render view without a visible window in python

python

opengl

pygame

pyopengl

opengl-compat