When I try to create a cube that can be moved around using the z-axis using a translation matrix, half of the cube doesn't render and when I try to change the z-value, the FOV seems to increase.
Is it because of the translation matrix, or is there some other error going on here, and how would I fix it?
Full code:
import glfw
import numpy
import pyrr
from OpenGL.GL import *
from OpenGL.GL.shaders import *
width, height = 500, 500
rot_x_var = 0
rot_y_var = 0
z = 0
def draw():
global shader, rot_x_var, rot_y_var, z
cube = [-0.5, -0.5, 0.5, 1.0, 0.0, 0.0, #red
0.5, -0.5, 0.5, 0.0, 1.0, 0.0, #green
0.5, 0.5, 0.5, 0.0, 0.0, 1.0, #blue
-0.5, 0.5, 0.5, 1.0, 1.0, 0.0, #yellow
-0.5, -0.5, -0.5, 0.0, 1.0, 1.0, #cyan
0.5, -0.5, -0.5, 1.0, 0.0, 1.0, #pink
0.5, 0.5, -0.5, 0.0, 0.5, 0.0, #half-green
-0.5, 0.5, -0.5, 1.0, 1.0, 1.0] #white
cube = numpy.array(cube, dtype = numpy.float32)
indices = [0, 3, 2, 2, 0, 1,
1, 2, 6, 6, 1, 5,
5, 1, 0, 0, 4, 5,
5, 4, 7, 7, 6, 5,
2, 6, 7, 7, 3, 2,
0, 4, 7, 7, 3, 0]
indices = numpy.array(indices, dtype= numpy.uint32)
vertex_shader_ = """
#version 140
in vec4 position;
in vec3 color;
uniform mat4 transform;
out vec4 out_color;
uniform ivec2 dim;
uniform mat4 z;
void main(){
gl_Position = transform*vec4(position.xyz, dim.x/dim.y)*z;
out_color = vec4(color.rgb, 0.9);
};
"""
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)
glLinkProgram(shader)
dim = glGetUniformLocation(shader, "dim")
glUniform2i(dim, int(width), int(height))
z_matrix = glGetUniformLocation(shader, "z")
z_trans = numpy.array([0, 0, z, 0])
glUniformMatrix4fv(z_matrix, 1, GL_FALSE, z_trans)
VBO = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, VBO)
glBufferData(GL_ARRAY_BUFFER, cube.nbytes, cube, 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, 3, GL_FLOAT, GL_FALSE, 24, ctypes.c_void_p(0))
glEnableVertexAttribArray(position)
color = glGetAttribLocation(shader, "color")
glVertexAttribPointer(color, 3, GL_FLOAT, GL_FALSE, 24, ctypes.c_void_p(12))
glEnableVertexAttribArray(color)
glEnable(GL_DEPTH_TEST)
rot_x = pyrr.Matrix44.from_x_rotation(rot_x_var)
rot_y = pyrr.Matrix44.from_y_rotation(rot_y_var)
transformLoc = glGetUniformLocation(shader, "transform")
glUniformMatrix4fv(transformLoc, 1, GL_FALSE, rot_x * rot_y)
def Screen():
glClearColor(0, 0, 0, 1)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL)
glDrawElements(GL_TRIANGLES, 64, GL_UNSIGNED_INT, None)
draw()
glViewport(0, 0, width, height)
def main():
global width, height, rot_x_var, rot_y_var, z
if not glfw.init():
return
window = glfw.create_window(500, 500, "PyOpenGL GLFW", None, None)
if not window:
glfw.terminate()
return
glfw.make_context_current(window)
while not glfw.window_should_close(window):
glfw.poll_events()
if glfw.get_key(window, glfw.KEY_DOWN) == glfw.PRESS:
rot_x_var += 0.01
if glfw.get_key(window, glfw.KEY_UP) == glfw.PRESS:
rot_x_var -= 0.01
if glfw.get_key(window, glfw.KEY_RIGHT) == glfw.PRESS:
rot_y_var += 0.01
if glfw.get_key(window, glfw.KEY_LEFT) == glfw.PRESS:
rot_y_var -= 0.01
if glfw.get_key(window, glfw.KEY_E) == glfw.PRESS:
z += 0.1
if glfw.get_key(window, glfw.KEY_Q) == glfw.PRESS:
z -= 0.1
Screen()
width, height = glfw.get_window_size(window)
glfw.swap_buffers(window)
glfw.terminate()
if __name__ == '__main__':
main()
Update: I have tweaked around with the code, and now the cube is not being shown, instead of the cube being deformed. Is there any way to fix this?
I had found the error. It was with this line:
z_trans = numpy.array([0, 0, z, 0])
I had to convert it to a matrix instead of an array.
z_trans = pyrr.Matrix44([1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, z,
0, 0, 0, 1])