在opengl中混合2d和3d(使用pyglet)

Question

我试图在pyglet中混合使用opengl中的2d和3d,即绘制一个3d场景,然后切换到正交投影并在顶部绘制内容.我绘制3d东西,将投影矩阵推到堆栈,做一个glOrtho投影矩阵,绘制2d的东西,然后从堆栈中弹出前一个矩阵.3d的东西很好,但由于某种原因,2d部分根本没有绘制,即使是单独的.这是代码:

class Window(pyglet.window.Window):

    # resolution
    width, height = 1024, 786

    def __init__(self, width, height):

        # initialise window
        super(Window, self).__init__(width, height)

        # set title
        self.set_caption("OpenGL Doss")

        # call update() at 30fps
        pyglet.clock.schedule_interval(self.update, 1 / 30.0)

        glEnable(GL_TEXTURE_2D)         # enable textures
        glShadeModel(GL_SMOOTH)         # smooth shading of polygons
        glClearColor(0.0, 0.0, 0.0, 0.0)

        glClearDepth(1.0)

        glDepthFunc(GL_LEQUAL)           
        glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST)   # make stuff look nice

        self.world = World()            # initialise world

        self.label = pyglet.text.Label('Hello, world',
                          font_name='Times New Roman',
                          font_size=20,
                          width=10, height=10)

    def on_resize(self, width, height):
        print 'on resize'
        if height == 0:
            height = 1
        glViewport(0, 0, width, height) # specify viewport

        # load perspective projection matrix
        glMatrixMode(GL_PROJECTION)
        glLoadIdentity()
        gluPerspective(45, 1.0 * width / height, 0.1, 100.0)
        #glLoadIdentity()

    def on_draw(self):
        self.set3d()

        # draw 3d stuff
        self.world.draw()

        self.set2d()

        # draw 2d stuff
        self.draw2d()

        self.unSet2d()

    def update(self, dt):
        "called at set interval during runtime"
        #maze = self.world.maze
        maze_platform = self.world.maze_platform

        pacman = maze_platform.maze.pacman

        maze_platform.update()

        # send it world pointer
        pacman.update(self.world)



    def on_key_press(self, symbol, modifiers):
        control.press(symbol, modifiers)

    def on_key_release(self, symbol, modifiers):
        control.release(symbol, modifiers)

    def set3d(self):
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        glEnable(GL_DEPTH_TEST)         # enable depth testing
        # reset modelview matrix
        glMatrixMode(GL_MODELVIEW)
        glLoadIdentity()

    def set2d(self):

        glDisable(GL_DEPTH_TEST)
        # store the projection matrix to restore later
        glMatrixMode(GL_PROJECTION)
        glPushMatrix()

        # load orthographic projection matrix
        glLoadIdentity()
        #glOrtho(0, float(self.width),0, float(self.height), 0, 1)
        far = 8192
        glOrtho(-self.width / 2., self.width / 2., -self.height / 2., self.height / 2., 0, far)

        # reset modelview
        glMatrixMode(GL_MODELVIEW)
        glLoadIdentity()

        #glClear(GL_COLOR_BUFFER_BIT)



    def unSet2d(self):

        # load back the projection matrix saved before
        glMatrixMode(GL_PROJECTION)
        glPopMatrix() 

    def draw2d(self):
        z=-6
        n=100
        glTranslatef(0, 0.0, -z)


        glBegin(GL_TRIANGLES)
        glVertex3f(0.0, n, 0.0)
        glVertex3f(-n, -n, 0)
        glVertex3f(n, -n, 0)
        glEnd()


def main():
    window = Window(Window.width, Window.height)
    pyglet.app.run()
    print 'framerate:', pyglet.clock.get_fps(), '(error checking = %s)' % pyglet.options['debug_gl']

if __name__ == '__main__': main()
    #command = 'main()'
    #cProfile.run(command)

Answer 1

我建议您在每次渲染时完全重置模型视图和投影矩阵，然后从 3d 转到 2d 时不要使用推送/弹出。

但是，我怀疑您使用了错误的坐标，因此场景是在剪裁平面之外绘制的。特别是我对将近剪裁平面设置为零有点怀疑。通常，二维元素是用 z=0 绘制的。

尝试将近剪辑平面设置为 -1。

我也有点不确定你为什么在draw2d中调用glTranslatef(0, 0.0, -z)，我不会打扰。