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The quad that I have created is not the same color as I specified. The quad is supposed to be completely red, as evidenced in the code below. The last three values in each row are the ones that specify the color.
quad = [-0.5, -0.5, 0.0, width / height, 1.0, 0.0, 0.0,
-0.5, 0.5, 0.0, width / height, 1.0, 0.0, 0.0,
0.5, 0.5, 0.0, width / height, 1.0, 0.0, 0.0,
0.5, -0.5, 0.0, width / height, 1.0, 0.0, 0.0]
Instead of the expected result, I get this:
How can I make the quad look fully red, and not multiple colors?
Full code:
import math
import glfw
import numpy
import pyrr
from OpenGL.GL import *
from OpenGL.GL.shaders import *
width, height = 500, 500
def draw():
global shader
quad = [-0.5, -0.5, 0.0, width / height, 1.0, 0.0, 0.0,
-0.5, 0.5, 0.0, width / height, 1.0, 0.0, 0.0,
0.5, 0.5, 0.0, width / height, 1.0, 0.0, 0.0,
0.5, -0.5, 0.0, width / height, 1.0, 0.0, 0.0]
quad = numpy.array(quad,
dtype='float32')
indices = [0, 1, 2, 3]
indices = numpy.array(indices, dtype='uint32')
vertex_shader_ = """
#version 140
in vec4 position;
in vec3 color;
uniform mat4 transform;
out vec4 out_color;
void main(){
gl_Position = position;
out_color = vec4(color.rgb, 1);
};
"""
fragment_shader_ = """
#version 140
in vec4 out_color;
void main(){
gl_FragColor = out_color;
};
"""
shader = compileProgram(compileShader(vertex_shader_, GL_VERTEX_SHADER),
compileShader(fragment_shader_, GL_FRAGMENT_SHADER))
glUseProgram(shader)
VBO = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, VBO)
glBufferData(GL_ARRAY_BUFFER, quad.nbytes, quad, GL_STATIC_DRAW)
EBO = glGenBuffers(1)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO)
glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.nbytes, indices, GL_STATIC_DRAW)
position = glGetAttribLocation(shader, "position")
glVertexAttribPointer(position, 4, GL_FLOAT, GL_FALSE, 28, ctypes.c_void_p(0))
glEnableVertexAttribArray(position)
color = glGetAttribLocation(shader, "color")
glVertexAttribPointer(color, 3, GL_FLOAT, GL_FALSE, 24, ctypes.c_void_p(16))
glEnableVertexAttribArray(color)
def Screen():
glClearColor(0, 0, 0, 1)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glDrawArrays(GL_POLYGON, 0, 4)
draw()
glViewport(0, 0, width, height)
def main():
global width, height
if not glfw.init():
return
window = glfw.create_window(500, 500, "Opengl GLFW Window", None, None)
if not window:
glfw.terminate()
return
glfw.make_context_current(window)
while not glfw.window_should_close(window):
glfw.poll_events()
Screen()
width, height = glfw.get_window_size(window)
print(width, height)
glViewport(0, 0, width, height)
glfw.swap_buffers(window)
glfw.terminate()
if __name__ == '__main__':
main()
The stride parameter in each glVertexAttribPointer() was given two different numbers. Thanks for #genpfault for pointing that out!
I have written this Python code which will draw a triangle in a window created using GLFW:
import glfw
from OpenGL.GL import *
from OpenGL.GL.shaders import compileProgram, compileShader
import numpy as np
vertex_src = """
# version 330 core
in vec3 a_position;
void main() {
gl_position = vec4(a_position, 1.0);
}
"""
fragment_src = """
# version 330 core
out vec4 out_color;
void main() {
out_color = vec4(1.0, 0.0, 0.0, 1.0);
}
"""
if not glfw.init():
print("Cannot initialize GLFW")
exit()
window = glfw.create_window(320, 240, "OpenGL window", None, None)
if not window:
glfw.terminate()
print("GLFW window cannot be creted")
exit()
glfw.set_window_pos(window, 100, 100)
glfw.make_context_current(window)
vertices = [-0.5, -0.5, 0.0,
0.5, -0.5, 0.0,
0.0, 0.5, 0.0]
colors = [1, 0, 0.0, 0.0,
0.0, 1.0, 0.0,
0.0, 0.0, 1.0]
vertices = np.array(vertices, dtype=np.float32)
colors = np.array(colors, dtype=np.float32)
shader = compileProgram(compileShader(
vertex_src, GL_VERTEX_SHADER), compileShader(fragment_src, GL_FRAGMENT_SHADER))
buff_obj = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, buff_obj)
glBufferData(GL_ARRAY_BUFFER, vertices.nbytes, vertices, GL_STATIC_DRAW)
position = glGetAttribLocation(shader, "a_position")
glEnableVertexAttribArray(position)
glVertexAttribPointer(position, 3, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(0))
glUseProgram(shader)
glClearColor(0, 0.1, 0.1, 1)
while not glfw.window_should_close(window):
glfw.poll_events()
glfw.swap_buffers(window)
glfw.terminate()
On running the program, I got this error:
Traceback (most recent call last):
File "opengl.py", line 43, in <module>
shader = compileProgram(compileShader(
File "/usr/local/lib/python3.8/dist-packages/OpenGL/GL/shaders.py", line 235, in compileShader
raise ShaderCompilationError(
OpenGL.GL.shaders.ShaderCompilationError: ("Shader compile failure (0): b'0:2(10): error: GLSL 3.30 is not supported. Supported versions are: 1.10, 1.20, 1.30, 1.00 ES, and 3.00 ES\\n'", [b'\n# version 330 core\nin vec3 a_position;\nvoid main() {\n gl_position = vec4(a_position, 1.0);\n}\n'], GL_VERTEX_SHADER)
It clearly indicates that GLSL 3.30 is not supported. But, this does work in C by setting window hints:
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
How can I set these window hints in Python?
With Python syntax it is
glfw.window_hint(glfw.CONTEXT_VERSION_MAJOR, 3)
glfw.window_hint(glfw.CONTEXT_VERSION_MINOR, 3)
Note, there is a typo in your fragment shader. GLSL is case sensitive. It has to be gl_Position rather than gl_position.
In a core profile OpenGL Context you've to use a named Vertex Array Object, because the default Vertex Array Object (0) is not valid:
vao = glGenVertexArrays(1) # <----
glBindVertexArray(vao) # <----
position = glGetAttribLocation(shader, "a_position")
glEnableVertexAttribArray(position)
glVertexAttribPointer(position, 3, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(0))
Finally you missed to draw the geometry. Clear the frame buffer and draw the array:
while not glfw.window_should_close(window):
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glDrawArrays(GL_TRIANGLES, 0, 3)
glfw.poll_events()
glfw.swap_buffers(window)
Complete example:
import glfw
from OpenGL.GL import *
from OpenGL.GL.shaders import compileProgram, compileShader
import numpy as np
vertex_src = """
# version 330 core
in vec3 a_position;
void main() {
gl_Position = vec4(a_position, 1.0);
}
"""
fragment_src = """
# version 330 core
out vec4 out_color;
void main() {
out_color = vec4(1.0, 0.0, 0.0, 1.0);
}
"""
if not glfw.init():
print("Cannot initialize GLFW")
exit()
glfw.window_hint(glfw.CONTEXT_VERSION_MAJOR, 3)
glfw.window_hint(glfw.CONTEXT_VERSION_MINOR, 3)
glfw.window_hint(glfw.OPENGL_FORWARD_COMPAT, True)
glfw.window_hint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE)
window = glfw.create_window(320, 240, "OpenGL window", None, None)
if not window:
glfw.terminate()
print("GLFW window cannot be creted")
exit()
glfw.set_window_pos(window, 100, 100)
glfw.make_context_current(window)
vertices = [-0.5, -0.5, 0.0,
0.5, -0.5, 0.0,
0.0, 0.5, 0.0]
colors = [1, 0, 0.0, 0.0,
0.0, 1.0, 0.0,
0.0, 0.0, 1.0]
vertices = np.array(vertices, dtype=np.float32)
colors = np.array(colors, dtype=np.float32)
shader = compileProgram(compileShader(
vertex_src, GL_VERTEX_SHADER), compileShader(fragment_src, GL_FRAGMENT_SHADER))
buff_obj = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, buff_obj)
glBufferData(GL_ARRAY_BUFFER, vertices.nbytes, vertices, GL_STATIC_DRAW)
vao = glGenVertexArrays(1)
glBindVertexArray(vao)
position = glGetAttribLocation(shader, "a_position")
glEnableVertexAttribArray(position)
glVertexAttribPointer(position, 3, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(0))
glUseProgram(shader)
glClearColor(0, 0.1, 0.1, 1)
while not glfw.window_should_close(window):
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glDrawArrays(GL_TRIANGLES, 0, 3)
glfw.poll_events()
glfw.swap_buffers(window)
glfw.terminate()
I am trying to transform the object using vector shader. But glUniformMatrixfv raises error while execution.
vertex_shader = shaders.compileShader(
"""
#version 330
layout (location = 0) in vec3 pos;
layout (location = 1) in vec3 color;
uniform mat4 movement;
out vec4 f_color;
void main()
{
gl_Position = movement * vec4(pos, 1.0);
f_color = vec4(color, 1.0);
}
"""
, GL_VERTEX_SHADER)
fragment_shader = shaders.compileShader(
"""
#version 330
in vec4 f_color;
out vec4 gl_FragColor;
void main()
{
gl_FragColor = f_color;
}
"""
, GL_FRAGMENT_SHADER
)
Program code to use these shaders is:
def draw_object(self):
self.vao = glGenVertexArrays(1)
glBindVertexArray(self.vao)
self.vbo_buffer = np.array([
-0.4, 0.2, 0.0, 0.0, 1.0, 0.0,
-0.8, -0.2, 0.0, 1.0, 1.0, 0.0,
0.0, -0.2, 0.0, 0.0, 1.0, 1.0,
0.2, -0.4, 0.0, 1.0, 0.0, 0.0,
0.8, -0.4, 0.0, 0.0, 0.0, 1.0,
0.8, 0.4, 0.0, 0.0, 1.0, 1.0,
0.2, -0.4, 0.0, 1.0, 0.0, 0.0,
0.8, 0.4, 0.0, 0.0, 0.0, 1.0,
0.2, 0.4, 0.0, 0.0, 1.0, 0.0
], dtype=np.float32)
self.vbo = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, self.vbo)
glBufferData(GL_ARRAY_BUFFER, self.vbo_buffer.nbytes, self.vbo_buffer, GL_DYNAMIC_DRAW)
self.vertex_position = glGetAttribLocation(self.shader, bytestr('pos'))
glVertexAttribPointer(self.vertex_position, 3, GL_FLOAT, GL_FALSE, 24, None)
glEnableVertexAttribArray(self.vertex_position)
self.vertex_color = glGetAttribLocation(self.shader, bytestr('color'))
glVertexAttribPointer(self.vertex_color, 3, GL_FLOAT, GL_FALSE, 24, ctypes.c_void_p(12))
glEnableVertexAttribArray(self.vertex_color)
self.movement = glGetUniformLocation(self.shader, 'movement')
glUniformMatrix4fv(self.movement, 1, GL_FALSE, glm.value_ptr(self.svp_matrix))
glBindBuffer(GL_ARRAY_BUFFER, 0)
glBindVertexArray(0)
def calculate_mvp(self):
self.projection_matrix = glm.perspective(glm.radians(self.fieldOfView), self.glWinWidth / self.glWinHeight,
self.nearPlane, self.farPlane)
self.view_matrix = glm.rotate(glm.mat4(1.0), float(self.xRot), glm.vec3(1.0, 0.0, 0.0)) * \
glm.rotate(glm.mat4(1.0), float(self.yRot), glm.vec3(0.0, 1.0, 0.0)) * \
glm.rotate(glm.mat4(1.0), float(self.zRot), glm.vec3(0.0, 0.0, 1.0)) * \
glm.translate(glm.mat4(1.0), glm.vec3(self.xTranslate, self.yTranslate, self.zTranslate))
self.scale_matrix = glm.scale(glm.mat4(1.0), glm.vec3(self.scale_factor))
self.svp_matrix = self.projection_matrix * self.view_matrix * self.scale_matrix
def paintGL(self):
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glUseProgram(self.shader)
try:
glBindVertexArray(self.vao)
glDrawArrays(GL_TRIANGLES, 0, 9)
finally:
glBindVertexArray(0)
glUseProgram(0)
glFlush()
Error I am getting is:
File "C:\Program Files\Python37\lib\site-packages\OpenGL\platform\baseplatform.py", line 415, in
__call__
return self( *args, **named )
File "src\errorchecker.pyx", line 58, in OpenGL_accelerate.errorchecker._ErrorChecker.glCheckError
OpenGL.error.GLError: GLError(
err = 1282,
description = b'invalid operation',
baseOperation = glUniformMatrix4fv,
pyArgs = (
0,
1,
GL_FALSE,
<OpenGL.GLU.tess.LP_c_float object at 0x0000013A37B1B4C8>,
),
cArgs = (
0,
1,
GL_FALSE,
<OpenGL.GLU.tess.LP_c_float object at 0x0000013A37B1B4C8>,
),
cArguments = (
0,
1,
GL_FALSE,
<OpenGL.GLU.tess.LP_c_float object at 0x0000013A37B1B4C8>,
)
)
If you know how to fix this please share below. Thanks
glUniformMatrix4fv sets the value of a uniform variable in the default uniform block currently installed program.
The means the program has to be installed by glUseProgram, before the variable can be set. If there is no current program object, then an GL_INVALID_OPERATION error is generated.
Install the program before glUniformMatrix4fv:
self.movement = glGetUniformLocation(self.shader, 'movement')
glUseProgram(self.shader)
glUniformMatrix4fv(self.movement, 1, GL_FALSE, glm.value_ptr(self.svp_matrix))
Porting over a chapter 7 example of instanced rendering from Superbible OpenGL 7th ed. and run into a problem with the function glBufferSubData
Whatever I do to it, it won't accept the data. Make it into a pointer, a byte string, list itself. Please help any assistance would be very much appreciated. Thank You.
Update: Using the excellent answer from Rabbid76 the function glBufferSubData is now accepting the data and the numpy version is very nice, the ctypes version is an insightful answer and very good to know. Also, about the 2nd parameter, it does indeed need to be a int or long, not a GLuint(0) in python.
Update and Success: Another very fine answer by Rabbid76 to get the rendering working.
The function glVertexAttribPointer needs a pointer to the lengths of the initial lists of data so it can offset. Thank You very much.
source code to: instancedattribs.py
#!/usr/bin/python3
import sys
import time
import ctypes
fullscreen = True
try:
from OpenGL.GLUT import *
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.raw.GL.ARB.vertex_array_object import glGenVertexArrays, glBindVertexArray
except:
print ('''
ERROR: PyOpenGL not installed properly.
''')
sys.exit()
import numpy as np
square_buffer = GLuint(0)
square_vao = GLuint(0)
square_program = GLuint(0)
square_vs_source = '''
#version 410 core
layout (location = 0) in vec4 position;
layout (location = 1) in vec4 instance_color;
layout (location = 2) in vec4 instance_position;
out Fragment
{
vec4 color;
} fragment;
void main(void)
{
gl_Position = (position + instance_position) * vec4(0.25, 0.25, 1.0, 1.0);
fragment.color = instance_color;
}
'''
square_fs_source = '''
#version 410 core
precision highp float;
in Fragment
{
vec4 color;
} fragment;
out vec4 color;
void main(void)
{
color = fragment.color;
}
'''
class Scene:
def __init__(self, width, height):
global square_buffer
global square_vao
global square_program
self.width = width
self.height = height
square_vertices = np.array([
-1.0, -1.0, 0.0, 1.0,
1.0, -1.0, 0.0, 1.0,
1.0, 1.0, 0.0, 1.0,
-1.0, 1.0, 0.0, 1.0], dtype='float32')
instance_colors = np.array([
1.0, 0.0, 0.0, 1.0,
0.0, 1.0, 0.0, 1.0,
0.0, 0.0, 1.0, 1.0,
1.0, 1.0, 0.0, 1.0], dtype='float32')
instance_positions = np.array([
-2.0, -2.0, 0.0, 0.0,
2.0, -2.0, 0.0, 0.0,
2.0, 2.0, 0.0, 0.0,
-2.0, 2.0, 0.0, 0.0], dtype='float32')
glGenVertexArrays(1, square_vao)
glGenBuffers(1, square_buffer)
glBindVertexArray(square_vao)
glBindBuffer(GL_ARRAY_BUFFER, square_buffer)
offset = 0 # not GLuint(0)
bufferSize = (len(square_vertices) + len(instance_colors) + len(instance_positions))*4
glBufferData(GL_ARRAY_BUFFER, bufferSize, None, GL_STATIC_DRAW)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(square_vertices)*4, square_vertices)
offset += len(square_vertices)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_colors)*4, instance_colors)
offset += len(instance_colors)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_positions)*4, instance_positions)
offset += len(instance_positions)*4
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, None)
offsetInstanceColor = len(square_vertices)*4
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstanceColor))
offsetInstancPosition = (len(instance_colors) + len(instance_positions))*4
glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstancPosition))
glEnableVertexAttribArray(0)
glEnableVertexAttribArray(1)
glEnableVertexAttribArray(2)
glVertexAttribDivisor(1, 1)
glVertexAttribDivisor(2, 1)
square_program = glCreateProgram()
square_vs = GLuint(0)
square_vs = glCreateShader(GL_VERTEX_SHADER)
glShaderSource(square_vs, square_vs_source)
glCompileShader(square_vs)
glAttachShader(square_program, square_vs)
square_fs = GLuint(0)
square_fs = glCreateShader(GL_FRAGMENT_SHADER)
glShaderSource(square_fs, square_fs_source)
glCompileShader(square_fs)
glAttachShader(square_program, square_fs)
glLinkProgram(square_program)
glDeleteShader(square_vs)
glDeleteShader(square_fs)
def display(self):
black = [ 0.0, 0.0, 0.0, 0.0 ]
glClearBufferfv(GL_COLOR, 0, black)
glUseProgram(square_program)
glBindVertexArray(square_vao)
glDrawArraysInstanced(GL_TRIANGLE_FAN, 0, 4, 4)
glutSwapBuffers()
def reshape(self, width, height):
self.width = width
self.height = height
def keyboard(self, key, x, y ):
global fullscreen
print ('key:' , key)
if key == b'\x1b': # ESC
sys.exit()
elif key == b'f' or key == b'F': #fullscreen toggle
if (fullscreen == True):
glutReshapeWindow(512, 512)
glutPositionWindow(int((1360/2)-(512/2)), int((768/2)-(512/2)))
fullscreen = False
else:
glutFullScreen()
fullscreen = True
print('done')
def init(self):
pass
def timer(self, blah):
glutPostRedisplay()
glutTimerFunc( int(1/60), self.timer, 0)
time.sleep(1/60.0)
if __name__ == '__main__':
start = time.time()
glutInit()
glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)
glutInitWindowSize(512, 512)
w1 = glutCreateWindow('OpenGL SuperBible - Instanced Attributes')
glutInitWindowPosition(int((1360/2)-(512/2)), int((768/2)-(512/2)))
fullscreen = False
many_cubes = False
#glutFullScreen()
scene = Scene(512,512)
glutReshapeFunc(scene.reshape)
glutDisplayFunc(scene.display)
glutKeyboardFunc(scene.keyboard)
glutIdleFunc(scene.display)
#glutTimerFunc( int(1/60), scene.timer, 0)
scene.init()
glutMainLoop()
expected rendering output:
Ported from: instancedattribs.cpp
In compare to glBufferData, PyOpenGl's glBufferSubData the size parameter can't be omitted.
You've to pass the size of the buffer (in bytes) and a pointer to the buffer. But note, the 2nd and the 3rd parameter have to be a python int or long, even PyOpneGL's GLuint will cause an error.
You've some possibilities, either create an array PyOpenGL's GLfloat
offset = 0
dataArray = (GLfloat*len(square_vertices))(*square_vertices)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
or use pythons built-in ctypes library:
import ctypes
offset = 0
dataArray = (ctypes.c_float*len(square_vertices))(*square_vertices)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
or create a NumPy array:
import numpy as np
offset = 0
dataArray = np.array(square_vertices, dtype='float32')
glBufferSubData(GL_ARRAY_BUFFER, offset, len(dataArray)*4, dataArray)
Note, for the 2nd and 3d parameter you can use a cast to either int (e.g int(offset)) or long (e.g. long(offset)).
Further note, the offset and size parameters to glBufferData, glBufferSubData and glVertexAttribPointer are values in size of bytes rather than the number of elements of the arrays.
The size in bytes is calculated by the number of elements multiplied by the size of 1 element.
The size of 1 element is 4, since the size of float (GLfloat, ctypes.c_float, 'float32') in bytes is 4.
If a named buffer object is bound, then the last parameter of glVertexAttribPointer is treated as a byte offset into the buffer object's data store, but the type of the parameter is still a pointer.
So you've to use ctypes.c_void_p(offset). If offset is 0 it is possible to pass None.
bufferSize = (len(square_vertices) + len(instance_colors) + len(instance_positions))*4
glBufferData(GL_ARRAY_BUFFER, bufferSize, None, GL_STATIC_DRAW)
glBufferSubData(GL_ARRAY_BUFFER, offset, len(square_vertices)*4, square_vertices)
offset += len(square_vertices)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_colors)*4, instance_colors)
offset += len(instance_colors)*4
glBufferSubData(GL_ARRAY_BUFFER, offset, len(instance_positions)*4, instance_positions)
offset += len(instance_positions)*4
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, None)
offsetInstanceColor = len(square_vertices)*4
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstanceColor))
offsetInstancPosition = (len(instance_colors) + len(instance_positions))*4
glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 0, ctypes.c_void_p(offsetInstancPosition))
I'm relatively new to PyOpenGL and started learning about transformations and model, view, and projection matrices. Which was fine until I compiled and ran my code, and found that my object suddenly disappeared, to be honest I don't know if OpenGL is clipping my object or simply not showing it because of some camera error, but I believe it has something to do with the projection matrix implemented in my code, because when I'd cut the projection matrix out of my code and would run my program, everything was suddenly working again, except for the fact I wouldn't have perspective projection implemented. Well anyways any would be very appreciated :D
Here's my PyOpenGL code.
import OpenGL, PIL, pygame, numpy, pyrr, math, sys, os
from OpenGL.GL import *
from PIL import Image
from pyrr import Matrix44, Vector4, Vector3, Quaternion
VERT_DATA = numpy.array([0.5, 0.5, 0.0,
0.5, -0.5, 0.0,
-0.5, -0.5, 0.0,
-0.5, 0.5, 0.0],
dtype="float32")
COLOR_DATA = numpy.array([1.0, 0.0, 0.0, 1.0,
0.0, 1.0, 0.0, 1.0,
0.0, 0.0, 1.0, 1.0,
0.0, 1.0, 1.0, 1.0],
dtype="float32")
TEXTURE_COORD_DATA = numpy.array([0.5, 0.5,
0.5, -0.5,
-0.5, -0.5,
-0.5, 0.5],
dtype="float32")
INDICES = numpy.array([0, 1, 3,
1, 2, 3],
dtype="int32")
class GLProgram:
def __init__(self):
self.gl_program = glCreateProgram()
self.mvp_matrix = self.projection()
self.shaders()
self.gl_buffers()
def gl_texture(self, texture_path):
image = Image.open(texture_path).transpose(Image.FLIP_TOP_BOTTOM)
image_data = numpy.fromstring(image.tobytes(), numpy.uint8)
width, height = image.size
texture = glGenTextures(1)
glBindTexture(GL_TEXTURE_2D, texture)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image_data)
glGenerateMipmap(GL_TEXTURE_2D)
return texture
def gl_buffers(self):
self.vao = glGenVertexArrays(1)
glBindVertexArray(self.vao)
self.pos_vbo = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, self.pos_vbo)
glBufferData(GL_ARRAY_BUFFER, VERT_DATA, GL_STATIC_DRAW)
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, None)
glEnableVertexAttribArray(0)
self.text_coord_vbo = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, self.text_coord_vbo)
glBufferData(GL_ARRAY_BUFFER, TEXTURE_COORD_DATA, GL_STATIC_DRAW)
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, None)
glEnableVertexAttribArray(1)
self.pos_ebo = glGenBuffers(1)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, self.pos_ebo)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, self.pos_ebo)
glBufferData(GL_ELEMENT_ARRAY_BUFFER, INDICES, GL_STATIC_DRAW)
self.brick_texture = self.gl_texture("check.jpg")
def shaders(self):
vertex_shader = glCreateShader(GL_VERTEX_SHADER)
fragment_shader = glCreateShader(GL_FRAGMENT_SHADER)
with open("VertexShader.vert", "r") as vert_file:
vert_source = vert_file.read()
with open("FragmentShader.frag", "r") as frag_file:
frag_source = frag_file.read()
glShaderSource(vertex_shader, vert_source)
glShaderSource(fragment_shader, frag_source)
glCompileShader(vertex_shader)
if not glGetShaderiv(vertex_shader, GL_COMPILE_STATUS):
info_log = glGetShaderInfoLog(vertex_shader)
print ("Compilation Failure for " + vertex_shader + " shader:\n" + info_log)
glCompileShader(fragment_shader)
if not glGetShaderiv(fragment_shader, GL_COMPILE_STATUS):
info_log = glGetShaderInfoLog(fragment_shader)
print ("Compilation Failure for " + fragment_shader + " shader:\n" + info_log)
glAttachShader(self.gl_program, vertex_shader)
glAttachShader(self.gl_program, fragment_shader)
glLinkProgram(self.gl_program)
glDeleteShader(vertex_shader)
glDeleteShader(fragment_shader)
def projection(self):
scale_matrix = pyrr.matrix44.create_from_scale(Vector3([1, 1, 1]))
rot_matrix = Matrix44.identity()
trans_matrix = pyrr.matrix44.create_from_translation(Vector3([1, 1, 0]))
model_matrix = scale_matrix * rot_matrix * trans_matrix
view_matrix = pyrr.matrix44.create_look_at(numpy.array([4, 3, 3]), numpy.array([1, 1, 0]), numpy.array([0, 1, 0]))
proj_matrix = pyrr.matrix44.create_perspective_projection_matrix(45.0, 1280/720, 0.1, 1000.0)
mvp_matrix = proj_matrix * view_matrix * model_matrix
return mvp_matrix
def display(self):
glEnable(GL_DEPTH_TEST)
glClearColor(0.0, 0.0, 0.0, 1.0)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glUseProgram(self.gl_program)
glActiveTexture(GL_TEXTURE0)
glBindTexture(GL_TEXTURE_2D, self.brick_texture)
texture_uniform = glGetUniformLocation(self.gl_program, "the_texture")
glUniform1i(texture_uniform, 0)
trans_uniform = glGetUniformLocation(self.gl_program, "mvp")
glUniformMatrix4fv(trans_uniform, 1, GL_FALSE, self.mvp_matrix)
glBindVertexArray(self.vao)
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, None)
glUseProgram(0)
def main():
pygame.init()
os.environ['SDL_VIDEO_CENTERED'] = '1'
pygame.display.set_caption("3D Graphics")
pygame.display.set_mode((1280, 720), pygame.DOUBLEBUF | pygame.OPENGL)
clock = pygame.time.Clock()
gl = GLProgram()
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
clock.tick(60)
gl.display()
pygame.display.flip()
if __name__ == "__main__":
main()
Vertex Shader:
#version 330 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec2 text_coord;
out vec2 final_text_coord;
uniform mat4 mvp;
void main() {
gl_Position = mvp * vec4(position, 1.0);
final_text_coord = text_coord;
}
Fragment Shader:
#version 330 core
in vec2 final_text_coord;
out vec4 frag_color;
uniform sampler2D the_texture;
void main() {
frag_color = texture(the_texture, final_text_coord);
}
There were a couple of issues with your code:
Matrix multiplication. Multiplying two 2-dimensional numpy arrays together results in a component-wise product, not in matrix multiplication. Using numpy.matmul will solve that one.
The matrix conventions were not clear.
As the documentation for pyrr states, matrices are laid out as row-major in memory, which is the opposite of GL's default convention. Furthermore, pyrr creates the matrices transposed to standrad GL conventions. One might think that both things will cancel itself out, that is only true to a certain extent. It will break whenever you actually do some other operations on these matrices (like multiplication), which will then use the native convention, and screw things up.
I did hack around in your code, providing two different solutions. Since you changed your code a bit between your question and your answer, I ended up with a wild mix of both versions. I also disabled the texturing stuff because I'm lacking some libraries (and the image files). I modified the fragment shader accordingly, but that is not important.
import OpenGL, PIL, pygame, numpy, pyrr, math, sys, os
from OpenGL.GL import *
from PIL import Image
from pyrr import Matrix44, Vector4, Vector3, Quaternion
VERT_DATA = numpy.array([0.5, 0.5, 0.0,
0.5, -0.5, 0.0,
-0.5, -0.5, 0.0,
-0.5, 0.5, 0.0],
dtype="float32")
COLOR_DATA = numpy.array([1.0, 0.0, 0.0, 1.0,
0.0, 1.0, 0.0, 1.0,
0.0, 0.0, 1.0, 1.0,
0.0, 1.0, 1.0, 1.0],
dtype="float32")
TEXTURE_COORD_DATA = numpy.array([0.5, 0.5,
0.5, -0.5,
-0.5, -0.5,
-0.5, 0.5],
dtype="float32")
INDICES = numpy.array([0, 1, 3,
1, 2, 3],
dtype="int32")
WINDOW_WIDTH=1280
WINDOW_HEIGHT=720
class GLProgram:
def __init__(self):
self.gl_program = glCreateProgram()
self.mvp_matrix = self.projection()
self.shaders()
self.gl_buffers()
self.cube_model_matrix, self.cube_view_matrix, self.cube_proj_matrix = self.gl_translate(Vector3([1.0, 1.0, 1.0]), 45.0, Vector3([0.5, 0.5, 0.5]))
self.cube_mvp = self.gl_translate3(Vector3([1.0, 1.0, 1.0]), -45.0, Vector3([0.5, 0.5, 0.5]))
def gl_texture(self, texture_path):
return 0
def gl_buffers(self):
self.vao = glGenVertexArrays(1)
glBindVertexArray(self.vao)
self.pos_vbo = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, self.pos_vbo)
glBufferData(GL_ARRAY_BUFFER, VERT_DATA, GL_STATIC_DRAW)
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, None)
glEnableVertexAttribArray(0)
self.text_coord_vbo = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, self.text_coord_vbo)
glBufferData(GL_ARRAY_BUFFER, TEXTURE_COORD_DATA, GL_STATIC_DRAW)
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, None)
glEnableVertexAttribArray(1)
self.pos_ebo = glGenBuffers(1)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, self.pos_ebo)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, self.pos_ebo)
glBufferData(GL_ELEMENT_ARRAY_BUFFER, INDICES, GL_STATIC_DRAW)
self.brick_texture = self.gl_texture("check.jpg")
def shaders(self):
vertex_shader = glCreateShader(GL_VERTEX_SHADER)
fragment_shader = glCreateShader(GL_FRAGMENT_SHADER)
with open("VertexShader.vert", "r") as vert_file:
vert_source = vert_file.read()
with open("FragmentShader.frag", "r") as frag_file:
frag_source = frag_file.read()
glShaderSource(vertex_shader, vert_source)
glShaderSource(fragment_shader, frag_source)
glCompileShader(vertex_shader)
if not glGetShaderiv(vertex_shader, GL_COMPILE_STATUS):
info_log = glGetShaderInfoLog(vertex_shader)
print ("Compilation Failure for " + vertex_shader + " shader:\n" + info_log)
glCompileShader(fragment_shader)
if not glGetShaderiv(fragment_shader, GL_COMPILE_STATUS):
info_log = glGetShaderInfoLog(fragment_shader)
print ("Compilation Failure for " + fragment_shader + " shader:\n" + info_log)
glAttachShader(self.gl_program, vertex_shader)
glAttachShader(self.gl_program, fragment_shader)
glLinkProgram(self.gl_program)
glDeleteShader(vertex_shader)
glDeleteShader(fragment_shader)
def projection(self):
scale_matrix = pyrr.matrix44.create_from_scale(Vector3([1, 1, 1]))
rot_matrix = Matrix44.identity()
trans_matrix = pyrr.matrix44.create_from_translation(Vector3([1, 1, 0]))
model_matrix = scale_matrix * rot_matrix * trans_matrix
view_matrix = pyrr.matrix44.create_look_at(numpy.array([4, 3, 3]), numpy.array([1, 1, 0]), numpy.array([0, 1, 0]))
proj_matrix = pyrr.matrix44.create_perspective_projection_matrix(45.0, 1280/720, 0.1, 1000.0)
mvp_matrix = proj_matrix * view_matrix * model_matrix
return mvp_matrix
def gl_translate(self, translation, rotation, scale):
trans_matrix = pyrr.matrix44.create_from_translation(translation)
rot_matrix = numpy.transpose(pyrr.matrix44.create_from_y_rotation(rotation))
scale_matrix = numpy.transpose(pyrr.matrix44.create_from_scale(scale))
model_matrix = scale_matrix * rot_matrix * trans_matrix
view_matrix = pyrr.matrix44.create_look_at(numpy.array([2.0, 2.0, 3.0], dtype="float32"),
numpy.array([0.0, 0.0, 0.0], dtype="float32"),
numpy.array([0.0, 1.0, 0.0], dtype="float32"))
proj_matrix = pyrr.matrix44.create_perspective_projection(45.0, WINDOW_WIDTH/WINDOW_HEIGHT, 0.1, 200.0)
return model_matrix, view_matrix, proj_matrix
def gl_translate2(self, translation, rotation, scale):
trans_matrix = pyrr.matrix44.create_from_translation(translation)
rot_matrix = pyrr.matrix44.create_from_y_rotation(rotation)
scale_matrix = pyrr.matrix44.create_from_scale(scale)
model_matrix = numpy.matmul(numpy.matmul(scale_matrix,rot_matrix),trans_matrix)
view_matrix = pyrr.matrix44.create_look_at(numpy.array([2.0, 2.0, 3.0], dtype="float32"),
numpy.array([0.0, 0.0, 0.0], dtype="float32"),
numpy.array([0.0, 1.0, 0.0], dtype="float32"))
proj_matrix = pyrr.matrix44.create_perspective_projection(45.0, WINDOW_WIDTH/WINDOW_HEIGHT, 0.1, 200.0)
m = numpy.matmul(numpy.matmul(model_matrix,view_matrix),proj_matrix)
return m
def gl_translate3(self, translation, rotation, scale):
trans_matrix = numpy.transpose(pyrr.matrix44.create_from_translation(translation))
rot_matrix = numpy.transpose(pyrr.matrix44.create_from_y_rotation(rotation))
scale_matrix = numpy.transpose(pyrr.matrix44.create_from_scale(scale))
model_matrix = numpy.matmul(numpy.matmul(trans_matrix,rot_matrix),scale_matrix)
view_matrix = numpy.transpose(pyrr.matrix44.create_look_at(numpy.array([2.0, 2.0, 3.0], dtype="float32"),
numpy.array([0.0, 0.0, 0.0], dtype="float32"),
numpy.array([0.0, 1.0, 0.0], dtype="float32")))
proj_matrix = numpy.transpose(pyrr.matrix44.create_perspective_projection(45.0, WINDOW_WIDTH/WINDOW_HEIGHT, 0.1, 200.0))
m = numpy.matmul(numpy.matmul(proj_matrix,view_matrix),model_matrix)
return numpy.transpose(m)
def display(self):
glEnable(GL_DEPTH_TEST)
glClearColor(0.0, 0.0, 0.0, 1.0)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glUseProgram(self.gl_program)
glActiveTexture(GL_TEXTURE0)
glBindTexture(GL_TEXTURE_2D, self.brick_texture)
texture_uniform = glGetUniformLocation(self.gl_program, "the_texture")
glUniform1i(texture_uniform, 0)
trans_uniform = glGetUniformLocation(self.gl_program, "mvp")
glUniformMatrix4fv(trans_uniform, 1, GL_FALSE, self.cube_mvp)
#model_location = glGetUniformLocation(self.gl_program, "model")
#glUniformMatrix4fv(model_location, 1, GL_FALSE, self.cube_model_matrix)
#view_location = glGetUniformLocation(self.gl_program, "view")
#glUniformMatrix4fv(view_location, 1, GL_FALSE, self.cube_view_matrix)
#proj_location = glGetUniformLocation(self.gl_program, "proj")
#glUniformMatrix4fv(proj_location, 1, GL_FALSE, self.cube_proj_matrix)
glBindVertexArray(self.vao)
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, None)
glUseProgram(0)
def main():
pygame.init()
os.environ['SDL_VIDEO_CENTERED'] = '1'
pygame.display.set_caption("3D Graphics")
pygame.display.set_mode((1280, 720), pygame.DOUBLEBUF | pygame.OPENGL)
clock = pygame.time.Clock()
gl = GLProgram()
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
clock.tick(60)
gl.display()
pygame.display.flip()
if __name__ == "__main__":
main()
with this Vertex Shader:
#version 330 core
layout (location = 0) in vec3 position;
layout (location = 1) in vec2 text_coord;
out vec2 final_text_coord;
uniform mat4 mvp;
void main() {
gl_Position = mvp * vec4(position, 1.0);
final_text_coord = text_coord;
}
and this Fragment Shader:
#version 330 core
in vec2 final_text_coord;
out vec4 frag_color;
uniform sampler2D the_texture;
void main() {
frag_color = vec4(1,0,0,1);
}
I specifically added the methods gl_translate2 and gl_translate3. Both result in the same matrix, the 2 variant is just using the native multiplication order convention of the pyrr library, and gl_translate3 use the GL conventions.
I also created the matrix with different parameters as
self.cube_mvp = self.gl_translate3(Vector3([1.0, 1.0, 1.0]), -45.0, Vector3([0.5, 0.5, 0.5]))
which differs in the negative sign for the rotation (and compensates for the additional transpose you do in gl_transaltion).
The result is different to what you got in your posted answer, but that is due to your model matrix being broken in that answer, as a result of the wrong multiplication function (which especially removed the translation part and distorted the rotation into some shear operation).
The result I'm getting with both gl_translate2 and gl_translate3 is:
and this looks very plausible for the parameters specified.