英文:
Is there a way to change the location and size of an imported .obj file in Pygame?
问题
我使用Blender创建了一个.obj文件，并使用OBJ文件加载器加载到Pygame中，如sugested by skrx在以下链接中：
https://stackoverflow.com/questions/47660370/error-in-objfileloader
是否有一种简单的方法在导入Pygame后更改导入的.obj文件的位置、高度和宽度？例如，如果您创建了一个tree.obj文件，要能够以不同的大小将相同的树放在不同的位置？
按照下面的代码，可能像这样：
object_obj = OBJ("Tree.obj", swapyz=False)
object_obj.setX = 0
object_obj.setWidth = 3
object_obj.setHeight = 10
或者通过向obj加载器发送额外的参数，改变顶点？
OBJ加载器：
import pygame
from OpenGL.GL import *
def MTL(filename):
filename = 'OBJ/' + filename
contents = {}
mtl = None
for line in open(filename, "r"):
if line.startswith('#'): continue
values = line.split()
if not values: continue
if values[0] == 'newmtl':
mtl = contents[values[1]] = {}
elif mtl is None:
raise ValueError("mtl file doesn't start with newmtl stmt")
elif values[0] == 'map_Kd':
# load the texture referred to by this declaration
mtl[values[0]] = values[1]
surf = pygame.image.load(mtl['map_Kd'])
image = pygame.image.tostring(surf, 'RGBA', 1)
ix, iy = surf.get_rect().size
texid = mtl['texture_Kd'] = glGenTextures(1)
glBindTexture(GL_TEXTURE_2D, texid)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
GL_LINEAR)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, ix, iy, 0, GL_RGBA,
GL_UNSIGNED_BYTE, image)
else:
mtl[values[0]] = list(map(float, values[1:]))
return contents
class OBJ:
def __init__(self, filename, swapyz=False):
"""Loads a Wavefront OBJ file."""
self.vertices = []
self.normals = []
self.texcoords = []
self.faces = []
material = None
for line in open(filename, "r"):
if line.startswith('#'): continue
values = line.split()
if not values: continue
if values[0] == 'v':
v = list(map(float, values[1:4]))
if swapyz:
v = v[0], v[2], v[1]
self.vertices.append(v)
elif values[0] == 'vn':
v = list(map(float, values[1:4]))
if swapyz:
v = v[0], v[2], v[1]
self.normals.append(v)
elif values[0] == 'vt':
self.texcoords.append(list(map(float, values[1:3])))
elif values[0] in ('usemtl', 'usemat'):
material = values[1]
elif values[0] == 'mtllib':
self.mtl = MTL(values[1])
elif values[0] == 'f':
face = []
texcoords = []
norms = []
for v in values[1:]:
w = v.split('/')
face.append(int(w[0]))
if len(w) >= 2 and len(w[1]) > 0:
texcoords.append(int(w[1]))
else:
texcoords.append(0)
if len(w) >= 3 and len(w[2]) > 0:
norms.append(int(w[2]))
else:
norms.append(0)
self.faces.append((face, norms, texcoords, material))
self.gl_list = glGenLists(1)
glNewList(self.gl_list, GL_COMPILE)
glEnable(GL_TEXTURE_2D)
glFrontFace(GL_CCW)
for face in self.faces:
vertices, normals, texture_coords, material = face
mtl = self.mtl[material]
if 'texture_Kd' in mtl:
# use diffuse texmap
glBindTexture(GL_TEXTURE_2D, mtl['texture_Kd'])
else:
# just use diffuse colour
glColor(*mtl['Kd'])
glBegin(GL_POLYGON)
for i in range(len(vertices)):
if normals[i] > 0:
glNormal3fv(self.normals[normals[i] - 1])
if texture_coords[i] > 0:
glTexCoord2fv(self.texcoords[texture_coords[i] - 1])
glVertex3fv(self.vertices[vertices[i] - 1])
glEnd()
glDisable(GL_TEXTURE_2D)
glEndList()
在Pygame中显示.OBJ文件：
# Basic OBJ file viewer. needs objloader from:
# http://www.pygame.org/wiki/OBJFileLoader
# LMB + move: rotate
# RMB + move: pan
# Scroll wheel: zoom in/out
import sys, pygame
from pygame.locals import *
from pygame.constants import *
from OpenGL.GL import *
from OpenGL.GLU import *
# IMPORT OBJECT LOADER
from OBJ_Loader import *
pygame.init()
viewport = (800,600)
hx = viewport[0]/2
hy = viewport[1]/2
srf = pygame.display.set_mode(viewport, OPENGL | DOUBLEBUF)
glLightfv(GL_LIGHT0, GL_POSITION, (-40, 200, 100, 0.0))
glLightfv(GL_LIGHT0, GL_AMBIENT, (0.2, 0.2, 0.2, 1.0))
glLightfv(GL_LIGHT0, GL_DIFFUSE, (0.5, 0.5, 0.5, 1.0))
glEnable(GL_LIGHT0)
glEnable(GL_LIGHTING)
glEnable(GL_COLOR_MATERIAL)
glEnable(GL_DEPTH_TEST)
glShadeModel(GL_SMOOTH) # most obj files expect to be smooth-shaded
# LOAD OBJECT AFTER PYGAME INIT
object_obj = OBJ("Tree.obj", swapyz=False)
clock = pygame.time.Clock()
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
width, height = viewport
gluPerspective(90, 1, 0.001, 1000.0)
glEnable(GL_DEPTH_TEST)
glMatrixMode(GL_MODELVIEW)
rx, ry = (0,0)
tx, ty = (0,0)
zpos = 1
rotate = move = False
while 1:
clock.tick(30)
for e in pygame.event.get():
if e.type == QUIT:
sys.exit()
elif e.type == KEYDOWN and e.key == K_ESCAPE:
sys.exit()
elif
<details>
<summary>英文:</summary>
I created an .obj file using blender and loaded into Pygame using the OBJfileloader as sugested by skrx in:
[https://stackoverflow.com/questions/47660370/error-in-objfileloader][1]
[1]: https://stackoverflow.com/questions/47660370/error-in-objfileloader
Is there an easy way to change the location, height and width of the imported .obj file after importing it into Pygame? As an example, if you create a tree.obj file, to be able to place that same tree in different places with different sizes?
Following the code below, maybe something like:
```py
object_obj = OBJ("Tree.obj", swapyz=False)
object_obj.setX = 0
object_obj.setWidth = 3
object_obj.setHeight =10
Or by sending extra parameters to the obj loader, changing the vertices?
OBJ Loader:
import pygame
from OpenGL.GL import *
def MTL(filename):
filename = 'OBJ/'+filename
contents = {}
mtl = None
for line in open(filename, "r"):
if line.startswith('#'): continue
values = line.split()
if not values: continue
if values[0] == 'newmtl':
mtl = contents[values[1]] = {}
elif mtl is None:
raise ValueError("mtl file doesn't start with newmtl stmt")
elif values[0] == 'map_Kd':
# load the texture referred to by this declaration
mtl[values[0]] = values[1]
surf = pygame.image.load(mtl['map_Kd'])
image = pygame.image.tostring(surf, 'RGBA', 1)
ix, iy = surf.get_rect().size
texid = mtl['texture_Kd'] = glGenTextures(1)
glBindTexture(GL_TEXTURE_2D, texid)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,
GL_LINEAR)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, ix, iy, 0, GL_RGBA,
GL_UNSIGNED_BYTE, image)
else:
mtl[values[0]] = list(map(float, values[1:]))
return contents
class OBJ:
def __init__(self, filename, swapyz=False):
"""Loads a Wavefront OBJ file. """
self.vertices = []
self.normals = []
self.texcoords = []
self.faces = []
material = None
for line in open(filename, "r"):
if line.startswith('#'): continue
values = line.split()
if not values: continue
if values[0] == 'v':
v = list(map(float, values[1:4]))
if swapyz:
v = v[0], v[2], v[1]
self.vertices.append(v)
elif values[0] == 'vn':
v = list(map(float, values[1:4]))
if swapyz:
v = v[0], v[2], v[1]
self.normals.append(v)
elif values[0] == 'vt':
self.texcoords.append(list(map(float, values[1:3])))
elif values[0] in ('usemtl', 'usemat'):
material = values[1]
elif values[0] == 'mtllib':
self.mtl = MTL(values[1])
elif values[0] == 'f':
face = []
texcoords = []
norms = []
for v in values[1:]:
w = v.split('/')
face.append(int(w[0]))
if len(w) >= 2 and len(w[1]) > 0:
texcoords.append(int(w[1]))
else:
texcoords.append(0)
if len(w) >= 3 and len(w[2]) > 0:
norms.append(int(w[2]))
else:
norms.append(0)
self.faces.append((face, norms, texcoords, material))
self.gl_list = glGenLists(1)
glNewList(self.gl_list, GL_COMPILE)
glEnable(GL_TEXTURE_2D)
glFrontFace(GL_CCW)
for face in self.faces:
vertices, normals, texture_coords, material = face
mtl = self.mtl[material]
if 'texture_Kd' in mtl:
# use diffuse texmap
glBindTexture(GL_TEXTURE_2D, mtl['texture_Kd'])
else:
# just use diffuse colour
glColor(*mtl['Kd'])
glBegin(GL_POLYGON)
for i in range(len(vertices)):
if normals[i] > 0:
glNormal3fv(self.normals[normals[i] - 1])
if texture_coords[i] > 0:
glTexCoord2fv(self.texcoords[texture_coords[i] - 1])
glVertex3fv(self.vertices[vertices[i] - 1])
glEnd()
glDisable(GL_TEXTURE_2D)
glEndList()
Displaying .OBJ file in Pygame:
# Basic OBJ file viewer. needs objloader from:
# http://www.pygame.org/wiki/OBJFileLoader
# LMB + move: rotate
# RMB + move: pan
# Scroll wheel: zoom in/out
import sys, pygame
from pygame.locals import *
from pygame.constants import *
from OpenGL.GL import *
from OpenGL.GLU import *
# IMPORT OBJECT LOADER
from OBJ_Loader import *
pygame.init()
viewport = (800,600)
hx = viewport[0]/2
hy = viewport[1]/2
srf = pygame.display.set_mode(viewport, OPENGL | DOUBLEBUF)
glLightfv(GL_LIGHT0, GL_POSITION, (-40, 200, 100, 0.0))
glLightfv(GL_LIGHT0, GL_AMBIENT, (0.2, 0.2, 0.2, 1.0))
glLightfv(GL_LIGHT0, GL_DIFFUSE, (0.5, 0.5, 0.5, 1.0))
glEnable(GL_LIGHT0)
glEnable(GL_LIGHTING)
glEnable(GL_COLOR_MATERIAL)
glEnable(GL_DEPTH_TEST)
glShadeModel(GL_SMOOTH) # most obj files expect to be smooth-shaded
# LOAD OBJECT AFTER PYGAME INIT
object_obj = OBJ("Tree.obj", swapyz=False)
clock = pygame.time.Clock()
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
width, height = viewport
gluPerspective(90, 1, 0.001, 1000.0)
glEnable(GL_DEPTH_TEST)
glMatrixMode(GL_MODELVIEW)
rx, ry = (0,0)
tx, ty = (0,0)
zpos = 1
rotate = move = False
while 1:
clock.tick(30)
for e in pygame.event.get():
if e.type == QUIT:
sys.exit()
elif e.type == KEYDOWN and e.key == K_ESCAPE:
sys.exit()
elif e.type == MOUSEBUTTONDOWN:
if e.button == 4: zpos = max(1, zpos-1)
elif e.button == 5: zpos += 1
elif e.button == 1: rotate = True
elif e.button == 3: move = True
elif e.type == MOUSEBUTTONUP:
if e.button == 1: rotate = False
elif e.button == 3: move = False
elif e.type == MOUSEMOTION:
i, j = e.rel
if rotate:
rx += i
ry += j
if move:
tx += i
ty -= j
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glLoadIdentity()
# RENDER OBJECT
glTranslate(tx/20., ty/20., - zpos)
glRotate(ry, 1, 0, 0)
glRotate(rx, 0, 1, 0)
glCallList(obj.gl_list)
pygame.display.flip()
答案1
得分: 3
<kbd>[![][1] repl.it/@Rabbid76/pygame-opengl-wavefront-obj](https://replit.com/@Rabbid76/pygame-opengl-wavefront-obj#main.py)</kbd>
不要更改顶点坐标。使用 [`glTranslate`](https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/glTranslate.xml) 和 [`glScale`](https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/glScale.xml) 来定义模型变换。
在读取顶点坐标时计算 [轴对齐边界框](https://en.wikipedia.org/wiki/Bounding_volume)：
```py
class OBJ:
def __init__(self, filename, swapyz=False):
"""加载 Wavefront OBJ 文件。"""
self.vertices = []
self.normals = []
self.texcoords = []
self.faces = []
self.min_v = [float("inf"), float("inf"), float("inf")]
self.max_v = [-float("inf"), -float("inf"), -float("inf")]
material = None
for line in open(filename, "r"):
if line.startswith('#'): continue
values = line.split()
if not values: continue
if values[0] == 'v':
v = list(map(float, values[1:4]))
if swapyz:
v = v[0], v[2], v[1]
for i in range(3):
self.min_v[i] = min(self.min_v[i], v[i])
self.max_v[i] = max(self.max_v[i], v[i])
self.vertices.append(v)
# [...]
self.size = [self.max_v[i]-self.min_v[i] for i in range(3)]
# [...]
在绘制对象时进行缩放和平移。使用 glPushMatrix / glPopMatrix 来保存和恢复当前矩阵，在变换前后使用：
# 渲染对象
glTranslate(tx/20., ty/20., - zpos)
glRotate(ry, 1, 0, 0)
glRotate(rx, 0, 1, 0)
pos = [0, 0, -5]
size = [3, 3, 10]
scale = [size[i]/obj.size[i] for i in range(3)]
glPushMatrix()
glTranslate(*pos)
glScale(*scale)
glCallList(obj.gl_list)
glPopMatrix()
或者也可以在显示列表中完成：
self.gl_list = glGenLists(1)
glNewList(self.gl_list, GL_COMPILE)
glEnable(GL_TEXTURE_2D)
glFrontFace(GL_CCW)
glPushMatrix()
glTranslate(*pos)
glScale(*scale)
for face in self.faces:
vertices, normals, texture_coords, material = face
# [...]
glDisable(GL_TEXTURE_2D)
glPopMatrix()
glEndList()
<details>
<summary>英文:</summary>
<kbd>[![][1] repl.it/@Rabbid76/pygame-opengl-wavefront-obj](https://replit.com/@Rabbid76/pygame-opengl-wavefront-obj#main.py)</kbd>
Do not change the vertex coordinates. Use [`glTranslate`](https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/glTranslate.xml) and [`glScale`](https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/glScale.xml) to define a model transformation.
Compute the [Axis Aligned Bounding Box](https://en.wikipedia.org/wiki/Bounding_volume), when the vertex coordinates are read:
```py
class OBJ:
def __init__(self, filename, swapyz=False):
"""Loads a Wavefront OBJ file. """
self.vertices = []
self.normals = []
self.texcoords = []
self.faces = []
self.min_v = [float("inf"), float("inf"), float("inf")]
self.max_v = [-float("inf"), -float("inf"), -float("inf")]
material = None
for line in open(filename, "r"):
if line.startswith('#'): continue
values = line.split()
if not values: continue
if values[0] == 'v':
v = list(map(float, values[1:4]))
if swapyz:
v = v[0], v[2], v[1]
for i in range(3):
self.min_v[i] = min(self.min_v[i], v[i])
self.max_v[i] = max(self.max_v[i], v[i])
self.vertices.append(v)
# [...]
self.size = [self.max_v[i]-self.min_v[i] for i in range(3)]
# [...]
Scale and translate the object when it is drawn. Use glPushMatrix / glPopMatrix to save and restore the current matrix before and after the transformations:
# RENDER OBJECT
glTranslate(tx/20., ty/20., - zpos)
glRotate(ry, 1, 0, 0)
glRotate(rx, 0, 1, 0)
pos = [0, 0, -5]
size = [3, 3, 10]
scale = [size[i]/obj.size[i] for i in range(3)]
glPushMatrix()
glTranslate(*pos)
glScale(*scale)
glCallList(obj.gl_list)
glPopMatrix()
Alternatively that can be done in the display list, too:
self.gl_list = glGenLists(1)
glNewList(self.gl_list, GL_COMPILE)
glEnable(GL_TEXTURE_2D)
glFrontFace(GL_CCW)
glPushMatrix()
glTranslate(*pos)
glScale(*scale)
for face in self.faces:
vertices, normals, texture_coords, material = face
# [...]
glDisable(GL_TEXTURE_2D)
glPopMatrix()
glEndList()
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