如何使用pygame和openGL修改摄像机视图

时间:2017-11-08 00:25:26

标签: python opengl pygame coordinate-transformation

我正在使用python3

我刚刚开始学习openGL,我需要一些帮助,用鼠标转动你的视图相机(就像一个FPS游戏)。现在我的程序看起来像是在移动,但我只是移动对象,所以如果你能告诉我如何移动相机(前进,后退等)也会很好。提前致谢

我的代码:

import pygame
from pygame.locals import *

from OpenGL.GL import *
from OpenGL.GLU import *



vertices = (
    (1, -1, -1),
    (1, 1, -1),
    (-1, 1, -1),
    (-1, -1, -1),
    (1, -1, 1),
    (1, 1, 1, ),
    (-1, -1, 1),
    (-1, 1, 1),
    )

edges = (
    (0,1),
    (0,3),
    (0,4),
    (2,1),
    (2,3),
    (2,7),
    (6,3),
    (6,4),
    (6,7),
    (5,1),
    (5,4),
    (5,7),
    )

surfaces = (
    (0,1,2,3),
    (3,2,7,6),
    (6,7,5,4),
    (4,5,1,0),
    (1,5,7,2),
    (4,0,3,6),
    )

colors = (
    (1,1,1),
    (0,0,0),
    (0,1,1),
    (0,0,0),
    (0,1,1),
    (1,0,1),
    (0,0,0),
    (1,1,1),
    (0,0,0),
    (0,1,1),
    )

def Cube():
    glBegin(GL_QUADS)


    for surface in surfaces:
        x = 0

        for vertex in surface:
            x += 1
            glColor3fv(colors[x])
            glVertex3fv(vertices[vertex])


    glEnd()

    glBegin(GL_LINES)
    for edge in edges:
        for vertex in edge:
            glVertex3fv(vertices[vertex])

    glEnd()


def main():
    pygame.init()
    x = 0
    y = 0
    z = 0
    display = (800,600)
    pygame.display.set_mode(display, DOUBLEBUF|OPENGL|RESIZABLE)
    pygame.event.set_grab(True)
    pygame.mouse.set_visible( False )


    gluPerspective(45, (display[0]/display[1]), 0.1, 50.0)

    glTranslatef(0, 0, -5)

    glRotatef(0, 0, 0, 0)

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()

            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_ESCAPE:
                    pygame.quit()
                    quit()

                if event.key == pygame.K_a:
                    x = 0.1

                elif event.key == pygame.K_d:
                    x = -0.1

                elif event.key == pygame.K_w:
                    z = 0.1

                elif event.key == pygame.K_s:
                    z = -0.1

            elif event.type == pygame.KEYUP:

                if event.key == pygame.K_a and x > 0:
                    x = 0

                elif event.key == pygame.K_d and x < 0:
                    x = 0

                if event.key == pygame.K_w and z > 0:
                    z = 0

                if event.key == pygame.K_s and z < 0:
                    z = 0

        glTranslatef(x,y,z)

        #glRotatef(1, 2, 3, 4)
        glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
        Cube()
        pygame.display.flip()
        pygame.time.wait(10)
main()

1 个答案:

答案 0 :(得分:1)

对于第一个人物移动,必须逐步更改相机矩阵。这意味着您必须计算当前运动和当前旋转矩阵。将移动和旋转应用到相机并使相机保持下一个循环周期。在循环的下一个循环中,您必须使用上一个循环中的受控相机,并且必须应用新的移动和旋转。这会导致相机增量变化,始终基于其当前位置和方向。

enter image description here


在渲染中,场景的每个网格通常由模型矩阵,视图矩阵和投影矩阵变换。投影矩阵描述了从场景的3D点到视口的2D点的映射。视图矩阵描述了查看场景的方向和位置。模型矩阵定义场景中网格的位置,方向和相对大小 (见Transform the modelMatrix
在OpenGL中,每种矩阵模式都有一个矩阵堆栈(参见glMatrixMode)。矩阵模式为GL_MODELVIEWGL_PROJECTIONGL_TEXTURE

这意味着您在设置投影时应使用GL_PROJECTION矩阵模式(gluPerspective):

glMatrixMode(GL_PROJECTION)
gluPerspective(45, (display[0]/display[1]), 0.1, 50.0)

对于第一人称视图矩阵,您需要一个存储它的变量:

import numpy

def IdentityMat44(): return numpy.matrix(numpy.identity(4), copy=False, dtype='float32')

view_mat = IdentityMat44()

view_mat应该使用初始位置进行初始化,您可以通过glGetFloatv(GL_MODELVIEW_MATRIX, view_mat)获取当前模型矩阵:

glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
glTranslatef(0, 0, -5)
glGetFloatv(GL_MODELVIEW_MATRIX, view_mat)
glLoadIdentity()

对于向左和向右旋转,您必须围绕y轴执行glRotatef的旋转:

glRotatef(ry, 0, 1, 0)

要逐步更改视图矩阵,您必须执行以下操作:

glLoadIdentity()
glTranslatef(tx,ty,tz)
glRotatef(ry, 0, 1, 0)
glMultMatrixf(view_mat)

glGetFloatv(GL_MODELVIEW_MATRIX, view_mat)

在你的循环结束时,你应该按glPushMatrix and glPopMatrix推送并弹出矩阵堆栈。


最终的功能看起来应该是这样的:

tx = 0
ty = 0
tz = 0
ry = 0

glMatrixMode(GL_PROJECTION)
gluPerspective(45, (display[0]/display[1]), 0.1, 50.0)

view_mat = IdentityMat44()
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
glTranslatef(0, 0, -5)
glGetFloatv(GL_MODELVIEW_MATRIX, view_mat)
glLoadIdentity()

while True:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            quit()

        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_ESCAPE:
                pygame.quit()
                quit()
            if   event.key == pygame.K_a:     tx =  0.1
            elif event.key == pygame.K_d:     tx = -0.1
            elif event.key == pygame.K_w:     tz =  0.1
            elif event.key == pygame.K_s:     tz = -0.1
            elif event.key == pygame.K_RIGHT: ry =  1.0
            elif event.key == pygame.K_LEFT:  ry = -1.0
        elif event.type == pygame.KEYUP: 
            if   event.key == pygame.K_a     and tx > 0: tx = 0
            elif event.key == pygame.K_d     and tx < 0: tx = 0
            elif event.key == pygame.K_w     and tz > 0: tz = 0
            elif event.key == pygame.K_s     and tz < 0: tz = 0
            elif event.key == pygame.K_RIGHT and ry > 0: ry = 0.0
            elif event.key == pygame.K_LEFT  and ry < 0: ry = 0.0

    glPushMatrix()
    glLoadIdentity()
    glTranslatef(tx,ty,tz)
    glRotatef(ry, 0, 1, 0)
    glMultMatrixf(view_mat)

    glGetFloatv(GL_MODELVIEW_MATRIX, view_mat)

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT)
    Cube()
    glPopMatrix()

    pygame.display.flip()
    pygame.time.wait(10)