我正在使用这个color_cube_actor.py文件，并且能够在使用我的HTC Vive时运行hello_qt_controllers.py示例，我确实看到了彩色立方体，并且我能够使用 roomscale 四处走动，所以一切都很好。
我想开始学习如何从 Python 实时更改缓冲区数据。
首先，我删除了 GLSL 程序的许多不必要的部分，并对其进行了修改，以将不露面的顶点渲染为 10 像素的白点。
尝试从 Python 循环中输入一个值以更改顶点点大小我正在尝试这个示例drawWithoutVBOs()，并根据样式修改了我的项目。
使用一个简单的静态不变变量 ( layout(location = 8) uniform float Size = 10;)，我的程序可以工作并生成上面的图像。
但是，如果我使用“可变”变量 ( layout(location = 8) in float Size;)，那么 Python 将完全崩溃而不会出现错误。
项目的源代码
#!/bin/env python
# file color_cube_actor.py
from textwrap import dedent
import numpy as np
from OpenGL.arrays import vbo
from OpenGL.GL import * # @UnusedWildImport # this comment squelches an IDE warning
from OpenGL.GL.shaders import compileShader, compileProgram
from pyqtgraph.opengl.shaders import getShaderProgram
class ColorCubeActor(object):
"""
Draws a cube
2________ 3
/| /|
6/_|____7/ |
| |_____|_|
| /0 | /1
|/______|/
4 5
"""
def __init__(self):
self.shader = 0
def init_gl(self):
vertex_shader = compileShader(dedent(
"""
#version 450 core
layout(location = 0) uniform mat4 Projection = mat4(1);
layout(location = 4) uniform mat4 ModelView = mat4(1);
//layout(location = 8) in float Size; //This causes Python to crash!
layout(location = 8) uniform float Size = 10;
vec3 UNIT_CUBE[8] = vec3[8](
vec3(-1.0, -0.0, -1.0), // 0: lower left rear
vec3(+1.0, -0.0, -1.0), // 1: lower right rear
vec3(-1.0, +2.0, -1.0), // 2: upper left rear
vec3(+1.0, +2.0, -1.0), // 3: upper right rear
vec3(-1.0, -0.0, +1.0), // 4: lower left front
vec3(+1.0, -0.0, +1.0), // 5: lower right front
vec3(-1.0, +2.0, +1.0), // 6: upper left front
vec3(+1.0, +2.0, +1.0) // 7: upper right front
);
out vec3 _color;
void main() {
_color = vec3(1.0, 1.0, 1.0);
gl_Position = Projection * ModelView * vec4(UNIT_CUBE[gl_VertexID] * 0.3, 1.0);
gl_PointSize = Size;
}
"""),
GL_VERTEX_SHADER)
fragment_shader = compileShader(dedent(
"""
#version 450 core
in vec3 _color;
out vec4 FragColor;
void main() {
FragColor = vec4(_color, 1.0);
}
"""),
GL_FRAGMENT_SHADER)
self.shader = compileProgram(vertex_shader, fragment_shader)
self.vao = glGenVertexArrays(1)
glBindVertexArray(self.vao)
self.vbo = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, self.vbo)
glBindAttribLocation(self.shader, 8, "Size")
glLinkProgram(self.shader)
glEnable(GL_VERTEX_PROGRAM_POINT_SIZE) #allow the program to specify the point size
glEnable(GL_DEPTH_TEST)
def setPointSize(self):
size = [10.0,10.0,10.0,10.0,10.0,10.0,10.0,10.0]
glEnableVertexAttribArray(8)
glVertexAttribPointer(8, 1, GL_FLOAT, GL_FALSE, 0, size)
def display_gl(self, modelview, projection):
glUseProgram(self.shader)
glBindBuffer(GL_ARRAY_BUFFER, self.vbo)
glBindVertexArray(self.vao)
glClear(GL_COLOR_BUFFER_BIT) #| GL_DEPTH_BUFFER_BIT)
glUniformMatrix4fv(0, 1, False, projection)
glUniformMatrix4fv(4, 1, False, modelview)
self.setPointSize()
glDrawArrays(GL_POINTS, 0, 8 )
glBindBuffer(GL_ARRAY_BUFFER, 0)
glBindVertexArray(0)
def dispose_gl(self):
glDeleteProgram(self.shader)
self.shader = 0
glDeleteVertexArrays(1, (self.vao,))
self.vao = 0
我不确定我是否遗漏了什么，或者我的项目是否可能使用 QT 后端而不是 PyGame，那么我的环境和其他导致问题的示例之间存在细微差别？
我希望这里有人可以帮助我弄清楚为什么向 gl_PointSize 提供值会导致 Python 崩溃。我对使用 PyOpenVR 库时可以实时修改缓冲区数据（位置、点大小等）的方法也很感兴趣？
谢谢你的帮助！
[更新]
这是我通过从GLSL 教程 – 属性变量中复制而修改的最新项目。现在这只会在 pyGame 和 pySide QT 中产生一个空白屏幕。
#!/bin/env python
# file color_cube_actor.py
import time
from textwrap import dedent
import numpy as np
from OpenGL.GL import * # @UnusedWildImport # this comment squelches an IDE warning
from OpenGL.GL.shaders import compileShader, compileProgram
import pygame
from pygame.locals import *
class ColorCubeActor(object):
array_size = 100
def __init__(self):
self.program = 0
self.scale = 0
self.indices = np.ascontiguousarray( np.arange(self.array_size), dtype=np.int)
self.colors = np.ascontiguousarray( np.tile(np.array([0.0,1.0,0.0]), (self.array_size,1)), dtype=np.float) #a bunch of green vertices
self.sizes = np.ascontiguousarray( np.ones(self.array_size)*10, dtype=np.float)
def init_gl(self):
glEnable(GL_VERTEX_PROGRAM_POINT_SIZE) #allow the program to specify the point size
vertex_shader = compileShader(dedent("""
#version 450 core
layout(location = 0) uniform mat4 Projection = mat4(1);
layout(location = 4) uniform mat4 ModelView = mat4(1);
in vec3 ptPosition;
in float ptSize;
in vec3 ptColor;
out vec3 _color;
void main()
{
_color = ptColor; //vec3(0.2, 0.5, 1.0); //light blue
gl_Position = Projection * ModelView * vec4(ptPosition, 1.0);
//use normalized device coordinates to calculate the PointSize of a vertex based on it's distance from the perspective camera.
//https://www.gamedev.net/topic/574695-gl_points-distance-attenuation/#
vec3 ndc = gl_Position.xyz / gl_Position.w ; // perspective divide.
float zDist = 1.0-ndc.z ; // 1 is close (right up in your face,)
// 0 is far (at the far plane)
gl_PointSize = ptSize*zDist ; // between 0 and 50 now.
}
"""), GL_VERTEX_SHADER)
fragment_shader = compileShader(dedent("""
#version 450 core
in vec3 _color;
out vec4 FragColor;
void main() {
FragColor = vec4(_color, 1.0); //just pass a color to the vertex (results in a rectangle pixel)
}
"""), GL_FRAGMENT_SHADER)
self.program = compileProgram(vertex_shader, fragment_shader)
#setup the vao and bind buffers (example: http://www.lighthouse3d.com/tutorials/glsl-tutorial/attribute-variables/ )
self.vao = glGenVertexArrays(1)
glBindVertexArray(self.vao)
self.ptSize = glGenBuffers(1) #bind buffer for point sizes
glBindBuffer(GL_ARRAY_BUFFER, self.ptSize) #GL_ARRAY_BUFFER is the buffer type we use to feed attributes
ptSize_pointer = glGetAttribLocation(self.program, "ptSize") #get the location of attribute "ptSize" from self.program
glBufferData(GL_ARRAY_BUFFER, self.sizes.nbytes, self.sizes, GL_STREAM_DRAW) #feed the buffer, and let OpenGL know that we don't plan to
glEnableVertexAttribArray(ptSize_pointer) #Enable the attribute at that location
glVertexAttribPointer(ptSize_pointer, 1, GL_FLOAT, GL_FALSE, 0, 0) #Tell OpenGL what the array contains:
self.ptColor = glGenBuffers(1) #bind buffer for point colors
glBindBuffer(GL_ARRAY_BUFFER, self.ptColor) #GL_ARRAY_BUFFER is the buffer type we use to feed attributes
ptColor_pointer = glGetAttribLocation(self.program, "ptColor") #get the location of attribute "ptSize" from self.program
glBufferData(GL_ARRAY_BUFFER, self.colors.nbytes, self.colors, GL_STREAM_DRAW) #feed the buffer, and let OpenGL know that we don't plan to
glEnableVertexAttribArray(ptColor_pointer) #Enable the attribute at that location
glVertexAttribPointer(ptColor_pointer, 3, GL_FLOAT, GL_FALSE, 0, 0) #Tell OpenGL what the array contains:
def setPoints(self, modelview, projection):
self.scale += 0.0005
#create dataset https://matplotlib.org/mpl_toolkits/mplot3d/tutorial.html
theta = np.linspace(-4 * np.pi, 4 * np.pi, self.array_size)
z = np.linspace(-2, 2, self.array_size)
r = z**2 + 1
x = r * np.sin(theta)
y = r * np.cos(theta)
plot = np.ascontiguousarray(np.dstack((x,y,z)) * self.scale, dtype=np.float)
self.ptPosition = glGenBuffers(1) #bind buffer for positions and copy data into buffer
glBindBuffer(GL_ARRAY_BUFFER, self.ptPosition) #GL_ARRAY_BUFFER is the buffer type we use to feed attributes
ptPosition_pointer = glGetAttribLocation(self.program, "ptPosition") #get the location of attribute "ptSize" from self.program
glBufferData(GL_ARRAY_BUFFER, plot.nbytes, plot, GL_STREAM_DRAW) #feed the buffer, and let OpenGL know that we don't plan to
glEnableVertexAttribArray(ptPosition_pointer) #Enable the attribute at that location
glVertexAttribPointer(ptPosition_pointer, 3, GL_FLOAT, GL_FALSE, 0, 0)#Tell OpenGL what the array contains:
glUniformMatrix4fv(0, 1, False, projection)
glUniformMatrix4fv(4, 1, False, modelview)
glDrawElements(GL_POINTS, self.array_size, GL_UNSIGNED_INT, self.indices)
def display_gl(self, modelview, projection):
glClear(GL_COLOR_BUFFER_BIT) #| GL_DEPTH_BUFFER_BIT)
glUseProgram(self.program)
self.setPoints(modelview, projection)
def dispose_gl(self):
glDeleteProgram(self.program)
self.program = 0
def main(self):
pygame.init()
pygame.display.set_mode((800, 600), HWSURFACE|OPENGL|DOUBLEBUF)
self.init_gl()
projection = np.array([#the matrix generated captured while using HTC Vive
[ 0.75752085, 0. , 0. , 0.],
[ 0. , 0.68160856, 0. , 0.],
[ 0.05516453, -0.00299519, -1.00040019, -1.],
[ 0. , 0. , -0.20008004, 0.]
])
modelview = np.array([#the matrix generated captured while using HTC Vive
[ 0.99030989, 0.04490654, 0.13141415, 0.],
[-0.01430531, 0.9742285 , -0.22510922, 0.],
[-0.13813627, 0.22104797, 0.9654305 , 0.],
[-0.12975544, -0.9294402 , -1.06236947, 1.]
])
start_time = time.time()
while time.time() - start_time < 5: #5 second animation
self.display_gl( modelview, projection)
pygame.display.flip()
if __name__ == '__main__':
t = ColorCubeActor()
t.main()
也再次感谢大家的帮助和患者！我知道我对 OpenGL 非常缺乏经验，非常感谢所有建议。
[更新]
很长一段时间以来，学习 OpenGL 可能是我尝试做的最困难的事情之一。我现在花了四天时间试图在 OpenGL 4.5 中设置缓冲区，但我几乎没有取得任何进展，我只是觉得自己陷入了困境。
这是我编写的一些代码的示例（它没有指定版本 4.5）。根据 Derhass 的建议，我尝试在此文件中使用 VBO，它们似乎可以工作，直到指定#version 450 core我得到的只是大量折旧错误和 1282 的位置。再次因为它不针对 OpenGL 4.5，我认为我不能将它与 OpenVR 一起使用（不知道为什么会这样？）。
#!/bin/env python
# coding: utf-8
import time
import numpy as np
from textwrap import dedent
from OpenGL.GL import *
from OpenGL.GL.shaders import compileShader, compileProgram
import pygame
from pygame.locals import *
##############################################################################
# OpenGL funcs
##############################################################################
buffers=None
shader = None
def init_gl():
glEnable(GL_VERTEX_PROGRAM_POINT_SIZE) #allow the program to specify the point size
global shader, buffers
vertex_shader = compileShader(dedent('''
uniform mat4 Projection = mat4(1);
uniform mat4 ModelView = mat4(1);
varying out vec3 _color;
void main() {
_color = gl_Color;
gl_Position = Projection * ModelView * gl_ModelViewProjectionMatrix * gl_Vertex;
vec3 ndc = gl_Position.xyz / gl_Position.w ; // perspective divide.
float zDist = 1.0-ndc.z ; // 1 is close (right up in your face,)
// 0 is far (at the far plane)
gl_PointSize = 25*zDist ; // between 0 and 50 now.
}
'''), GL_VERTEX_SHADER)
fragment_shader = compileShader(dedent('''
in vec3 _color;
void main() {
gl_FragColor = vec4(_color, 1.0); //gl_Color;
}
'''), GL_FRAGMENT_SHADER)
shader = compileProgram(vertex_shader, fragment_shader)
buffers=create_vbo()
yaw=0
pitch=0
def draw():
global yaw, pitch
glClear(GL_COLOR_BUFFER_BIT)# | GL_DEPTH_BUFFER_BIT)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
yaw+=0.39
pitch+=0.27
glTranslatef(0.0, 0.0, 0.0)
glRotatef(yaw, 0, 1, 0)
glRotatef(pitch, 1, 0, 0)
setPoints()
glFlush()
##############################################################################
# vertices
##############################################################################
array_size = 100
scale = 0.15
#create dataset https://matplotlib.org/mpl_toolkits/mplot3d/tutorial.html
theta = np.linspace(-4 * np.pi, 4 * np.pi, array_size)
z = np.linspace(-2, 2, array_size)
r = z**2 + 1
x = r * np.sin(theta)
y = r * np.cos(theta)
vertices = np.dstack((x,y,z)) * scale
colors = np.tile(np.array([0.0, 1.0, 0.0]), (array_size,1)) #a bunch of green vertices
indices=np.arange(array_size)
def create_vbo():
buffers = glGenBuffers(3)
glBindBuffer(GL_ARRAY_BUFFER, buffers[0])
glBufferData(GL_ARRAY_BUFFER,
vertices.nbytes, # byte size
(ctypes.c_float*len(vertices.flat))(*vertices.flat),
GL_STREAM_DRAW)
glBindBuffer(GL_ARRAY_BUFFER, buffers[1])
glBufferData(GL_ARRAY_BUFFER,
colors.nbytes, # byte size
(ctypes.c_float*len(colors.flat))(*colors.flat),
GL_STATIC_DRAW)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffers[2])
glBufferData(GL_ELEMENT_ARRAY_BUFFER,
indices.nbytes, # byte size
(ctypes.c_uint*len(indices.flat))(*indices.flat),
GL_STATIC_DRAW)
return buffers
def draw_vbo():
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, buffers[0]);
glVertexPointer(3, GL_FLOAT, 0, None);
glBindBuffer(GL_ARRAY_BUFFER, buffers[1]);
glColorPointer(3, GL_FLOAT, 0, None);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffers[2]);
glDrawElements(GL_POINTS, indices.size, GL_UNSIGNED_INT, None);
glDisableClientState(GL_COLOR_ARRAY)
glDisableClientState(GL_VERTEX_ARRAY);
def setPoints():
global shader
glUseProgram(shader)
draw_vbo()
projection = np.array([#the matrix generated captured while using HTC Vive
[ 0.75752085, 0. , 0. , 0.],
[ 0. , 0.68160856, 0. , 0.],
[ 0.05516453, -0.00299519, -1.00040019, -1.],
[ 0. , 0. , -0.20008004, 0.]
])
modelview = np.array([#the matrix generated captured while using HTC Vive
[ 0.99030989, 0.04490654, 0.13141415, 0.],
[-0.01430531, 0.9742285 , -0.22510922, 0.],
[-0.13813627, 0.22104797, 0.9654305 , 0.],
[-0.12975544, -0.9294402 , -1.06236947, 1.]
])
glUniformMatrix4fv(glGetUniformLocation(shader, "Projection"), 1, False, projection)
glUniformMatrix4fv(glGetUniformLocation(shader, "ModelView"), 1, False, modelview)
glUseProgram(0)
##############################################################################
if __name__ == '__main__':
pygame.init()
pygame.display.set_mode((800, 600), HWSURFACE|OPENGL|DOUBLEBUF)
init_gl()
start_time = time.time()
while time.time() - start_time < 5: #5 second animation
draw()
pygame.display.flip()
所以我尝试将它重写为 Python Class() 但即使它看起来相同，由于某种原因我只看到一个顶点在移动，其余的谁知道在哪里：
#!/bin/env python
# coding: utf-8
import time
import numpy as np
from textwrap import dedent
from OpenGL.GL import *
from OpenGL.GL.shaders import compileShader, compileProgram
import pygame
from pygame.locals import *
class ObjectActor(object):
array_size = 100
def __init__(self):
self.buffers=None
self.shader=None
self.vertices = self.get_vertices()
self.colors = np.tile(np.array([0.0, 1.0, 0.0]), (self.array_size,1)) #a bunch of green vertices
self.indices = np.arange(self.array_size)
def init_gl(self):
##############################################################################
# OpenGL funcs
##############################################################################
glEnable(GL_VERTEX_PROGRAM_POINT_SIZE) #allow the program to specify the point size
vertex_shader = compileShader(dedent('''
uniform mat4 Projection = mat4(1);
uniform mat4 ModelView = mat4(1);
varying out vec3 _color;
void main() {
_color = gl_Color;
gl_Position = Projection * ModelView * gl_ModelViewProjectionMatrix * gl_Vertex;
vec3 ndc = gl_Position.xyz / gl_Position.w ; // perspective divide.
float zDist = 1.0-ndc.z ; // 1 is close (right up in your face,)
// 0 is far (at the far plane)
gl_PointSize = 25*zDist ; // between 0 and 50 now.
}
'''), GL_VERTEX_SHADER)
fragment_shader = compileShader(dedent('''
in vec3 _color;
void main() {
gl_FragColor = vec4(_color, 1.0); //gl_Color;
}
'''), GL_FRAGMENT_SHADER)
self.shader = compileProgram(vertex_shader, fragment_shader)
self.create_vbo()
def display_gl(self, modelview, projection):
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
self.setPoints(modelview, projection)
glFlush()
def get_vertices(self):
##############################################################################
# vertices
##############################################################################
scale = 0.15
theta = np.linspace(-4 * np.pi, 4 * np.pi, self.array_size)
z = np.linspace(-2, 2, self.array_size)
r = z**2 + 1
x = r * np.sin(theta)
y = r * np.cos(theta)
return np.dstack((x,y,z)) * scale
def create_vbo(self):
self.buffers = glGenBuffers(3)
glBindBuffer(GL_ARRAY_BUFFER, self.buffers[0])
glBufferData(GL_ARRAY_BUFFER,
self.vertices.nbytes, # byte size
(ctypes.c_float*len(self.vertices.flat))(*self.vertices.flat),
GL_STREAM_DRAW)
glBindBuffer(GL_ARRAY_BUFFER, self.buffers[1])
glBufferData(GL_ARRAY_BUFFER,
self.colors.nbytes, # byte size
(ctypes.c_float*len(self.colors.flat))(*self.colors.flat),
GL_STATIC_DRAW)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, self.buffers[2])
glBufferData(GL_ELEMENT_ARRAY_BUFFER,
self.indices.nbytes, # byte size
(ctypes.c_float*len(self.indices.flat))(*self.indices.flat),
GL_STATIC_DRAW)
def draw_vbo(self):
glEnableClientState(GL_VERTEX_ARRAY)
glEnableClientState(GL_COLOR_ARRAY)
glBindBuffer(GL_ARRAY_BUFFER, self.buffers[0])
glVertexPointer(3, GL_FLOAT, 0, None)
glBindBuffer(GL_ARRAY_BUFFER, self.buffers[1])
glColorPointer(3, GL_FLOAT, 0, None)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, self.buffers[2])
glDrawElements(GL_POINTS, self.indices.size, GL_UNSIGNED_INT, None)
glDisableClientState(GL_COLOR_ARRAY)
glDisableClientState(GL_VERTEX_ARRAY)
def setPoints(self, modelview, projection):
glUseProgram(self.shader)
self.draw_vbo()
glUniformMatrix4fv(glGetUniformLocation(self.shader, "Projection"), 1, False, projection)
glUniformMatrix4fv(glGetUniformLocation(self.shader, "ModelView"), 1, False, modelview)
glUseProgram(0)
def main(self):
pygame.init()
pygame.display.set_mode((800, 600), HWSURFACE|OPENGL|DOUBLEBUF)
self.init_gl()
projection = np.array([#the matrix generated captured while using HTC Vive
[ 0.75752085, 0. , 0. , 0.],
[ 0. , 0.68160856, 0. , 0.],
[ 0.05516453, -0.00299519, -1.00040019, -1.],
[ 0. , 0. , -0.20008004, 0.]
])
modelview = np.array([#the matrix generated captured while using HTC Vive
[ 0.99030989, 0.04490654, 0.13141415, 0.],
[-0.01430531, 0.9742285 , -0.22510922, 0.],
[-0.13813627, 0.22104797, 0.9654305 , 0.],
[-0.12975544, -0.9294402 , -1.06236947, 1.]
])
yaw=0
pitch=0
start_time = time.time()
while time.time() - start_time < 5: #5 second animation
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
yaw+=0.39
pitch+=0.27
glTranslatef(0.0, 0.0, 0.0)
glRotatef(yaw, 0, 1, 0)
glRotatef(pitch, 1, 0, 0)
self.display_gl(modelview, projection)
pygame.display.flip()
##############################################################################
if __name__ == '__main__':
t = ObjectActor()
t.main()
在这一点上，我肯定在考虑 PyOpenGL 的工作方式有问题或者我只是无法弄清楚如何使用它的可能性。无论哪种方式，它都是一个真正的无赖..