受我对这个问题的不完整回答的启发,我正在根据本教程在 PyOpenGL 中实现一个简单的天空盒,并根据 OpenGL 2.1/GLSL 120 和 python2.7-isms 的需要进行微调。在大多数情况下,它可以成功运行,但是根据我传递给立方体贴图的六张图像,图像要么最终在一对相反的面之间交换,要么随机旋转!下面是这个演示的主要类:
import pygame
import sys
import time
import glob
import numpy as np
from ctypes import *
from OpenGL.GL import *
from OpenGL.GL import shaders
from OpenGL.GLU import *
def load_shaders(vert_url, frag_url):
vert_str = "\n".join(open(vert_url).readlines())
frag_str = "\n".join(open(frag_url).readlines())
vert_shader = shaders.compileShader(vert_str, GL_VERTEX_SHADER)
frag_shader = shaders.compileShader(frag_str, GL_FRAGMENT_SHADER)
program = shaders.compileProgram(vert_shader, frag_shader)
return program
def load_cubemap(folder_url):
tex_id = glGenTextures(1)
face_order = ["right", "left", "top", "bottom", "back", "front"]
"""
#hack that fixes issues for ./images1/
face_order = ["right", "left", "top", "bottom", "front", "back"]
"""
face_urls = sorted(glob.glob(folder_url + "*"))
glActiveTexture(GL_TEXTURE0)
glBindTexture(GL_TEXTURE_CUBE_MAP, tex_id)
for i, face in enumerate(face_order):
face_url = [face_url for face_url in face_urls if face in face_url.lower()][0]
face_image = pygame.image.load(face_url).convert()
"""
#hack that fixes issues for ./images2/
if face == "bottom":
face_image = pygame.transform.rotate(face_image, 270)
if face == "top":
face_image = pygame.transform.rotate(face_image, 90)
"""
"""
#hack that fixes issues for ./images3/
if face == "bottom" or face == "top":
face_image = pygame.transform.rotate(face_image, 180)
"""
face_surface = pygame.image.tostring(face_image, 'RGB')
face_width, face_height = face_image.get_size()
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, face_width, face_height, 0, GL_RGB, GL_UNSIGNED_BYTE, face_surface)
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE)
glBindTexture(GL_TEXTURE_CUBE_MAP, 0)
return tex_id
def render():
global width, height, program
global rotation, cubemap
glEnable(GL_DEPTH_TEST)
glEnable(GL_TEXTURE_2D)
glEnable(GL_TEXTURE_CUBE_MAP)
skybox_right = [1, -1, -1, 1, -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, 1, -1, -1]
skybox_left = [-1, -1, 1, -1, -1, -1, -1, 1, -1, -1, 1, -1, -1, 1, 1, -1, -1, 1]
skybox_top = [-1, 1, -1, 1, 1, -1, 1, 1, 1, 1, 1, 1, -1, 1, 1, -1, 1, -1]
skybox_bottom = [-1, -1, -1, -1, -1, 1, 1, -1, -1, 1, -1, -1, -1, -1, 1, 1, -1, 1]
skybox_back = [-1, 1, -1, -1, -1, -1, 1, -1, -1, 1, -1, -1, 1, 1, -1, -1, 1, -1]
skybox_front = [-1, -1, 1, -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, 1, -1, -1, 1]
skybox_vertices = np.array([skybox_right, skybox_left, skybox_top, skybox_bottom, skybox_back, skybox_front], dtype=np.float32).flatten()
skybox_vbo = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, skybox_vbo)
glBufferData(GL_ARRAY_BUFFER, skybox_vertices.nbytes, skybox_vertices, GL_STATIC_DRAW)
glBindBuffer(GL_ARRAY_BUFFER, 0)
glClear(GL_COLOR_BUFFER_BIT)
glClear(GL_DEPTH_BUFFER_BIT)
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluPerspective(60, float(width)/height, 0.1, 1000)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
#glRotate(rotation, 0, 1, 0)#spin around y axis
#glRotate(rotation, 1, 0, 0)#spin around x axis
glRotate(rotation, 1, 1, 1)#rotate around x, y, and z axes
glUseProgram(program)
glDepthMask(GL_FALSE)
glBindTexture(GL_TEXTURE_CUBE_MAP, cubemap)
glEnableClientState(GL_VERTEX_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, skybox_vbo)
glVertexPointer(3, GL_FLOAT, 0, None)
glDrawArrays(GL_TRIANGLES, 0, 36)
glBindBuffer(GL_ARRAY_BUFFER, 0)
glDisableClientState(GL_VERTEX_ARRAY)
glBindTexture(GL_TEXTURE_CUBE_MAP, 0)
glDepthMask(GL_TRUE)
glUseProgram(0)
pygame.display.flip()
if __name__ == "__main__":
title = "Skybox"
target_fps = 60
(width, height) = (800, 600)
flags = pygame.DOUBLEBUF|pygame.OPENGL
screen = pygame.display.set_mode((width, height), flags)
prev_time = time.time()
rotation = 0
cubemap = load_cubemap("./images1/")#front and back images appear swapped
#cubemap = load_cubemap("./images2/")#top and bottom images appear rotated by 90 and 270 degrees respectively
#cubemap = load_cubemap("./images3/")#top and bottom images appear rotated by 180 degrees
program = load_shaders("./shaders/skybox.vert", "./shaders/skybox.frag")
pause = False
while True:
#Handle the events
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
pause = not pause
#Do computations and render stuff on screen
if not pause:
rotation += 1
render()
#Handle timing code for desired FPS
curr_time = time.time()
diff = curr_time - prev_time
delay = max(1.0/target_fps - diff, 0)
time.sleep(delay)
fps = 1.0/(delay + diff)
prev_time = curr_time
pygame.display.set_caption("{0}: {1:.2f}".format(title, fps))
我使用以下顶点和片段着色器来显示天空盒的立方体贴图:
./shaders/skybox.vert
#version 120
varying vec3 tex_coords;
void main()
{
gl_Position = gl_ProjectionMatrix * gl_ModelViewMatrix * gl_Vertex;
tex_coords = vec3(gl_Vertex);
}
./shaders/skybox.frag
#version 120
varying vec3 tex_coords;
uniform samplerCube skybox;
void main()
{
gl_FragColor = textureCube(skybox, tex_coords);
}
我相信在玩了很多之后,错误在于 pygame 加载天空盒图像。我已经测试了三组天空盒图像。每个都有不同的视觉错误和修复它们的技巧,我在上面的代码中已经注意到了。以下是用于测试的三个天空盒的来源(请务必重命名图像,以便它们包含right
、left
、top
、bottom
、back
或front
在它们各自的文件名中)。
所有这三个天空盒都使用不同的图像格式(分别为 bmp、tga 和 png)。如何在不依赖看似随机的旋转或图像交换的情况下始终如一地处理所有这些和未来的图像案例?任何帮助或见解将不胜感激。
更新: 我创建了一个github 存储库,您可以在其中测试代码,而无需创建 main.py 和着色器、下载图像以及自己重命名和组织内容。如果您有兴趣对其进行测试,这应该会使代码更容易运行。
以下是我正在使用的所有内容的版本:
- 蟒蛇2.7.12
- pygame 1.9.2b1
- pyopengl 3.1.0(使用 opengl 2.1 和 GLSL 120)
如果您需要任何其他信息,请告诉我!