问题
I created an .obj file using blender and loaded into Pygame using the OBJfileloader as sugested by skrx in: 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:
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()
回答1:
Do not change the vertex coordinates. Use glTranslate and glScale to define a model transformation.
Compute the Axis Aligned Bounding Box, when the vertex coordinates are read:
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()
来源：https://stackoverflow.com/questions/59609837/is-there-a-way-to-change-the-location-and-size-of-an-imported-obj-file-in-pygam