顺序导入 .obj 文件很快就会变得非常慢

Sequentially importing .obj files becomes drastically slow very quickly

我写了一个非常简单的脚本,一个一个地导入许多 obj 文件并渲染它们。导入的网格有 ~10k 到 ~120k 个顶点。渲染后,我在导入下一个之前完全删除 导入的网格(及其数据块)。但是,随着 for 循环的进行,导入过程变得极其缓慢。我注意到导入函数开始以奇怪的方式运行,并且导入对象需要花费大量时间。我不确定为什么会这样。最初我认为是内存问题导致的,但我认为删除数据块应该可以解决内存泄漏问题。即使没有对导入的对象进行任何渲染或任何操作,也会发生这种情况。这是导入网格时导入函数打印的实例:

(  0.0002 sec |   0.0002 sec) Importing OBJ '/data/e1f2651d55aecd7d8f2b6fca0ec9a39dn7a9/models/model.obj'...
(  0.0308 sec |   0.0306 sec) Parsing OBJ file...
(  1.8534 sec |   1.8511 sec) Done, loading materials and images...
(  2.0450 sec |   2.0426 sec) Done, building geometries (verts:72707 faces:137005 materials: 44 smoothgroups:0) ...
(  5.4944 sec |   5.4921 sec) Done.
(  5.4946 sec |   5.4945 sec) Finished importing: 'data/e1f2651d55aecd7d8f2b6fca0ec9a39dn7a9/models/model.obj'
Progress: 100.00%

随着导入的对象越来越多,导入函数的运行速度越来越慢,即使对于更简单的形状(例如约 12k 个顶点),您也会得到类似这样的结果:

(  0.0002 sec |   0.0002 sec) Importing OBJ '/data/jjgd2e3f46f7cc1e8ba69a5e14689f7b974/models/model.obj'...
  (  0.0266 sec |   0.0263 sec) Parsing OBJ file...
    (  0.7060 sec |   0.6793 sec) Done, loading materials and images...
    (  3.0993 sec |   3.0726 sec) Done, building geometries (verts:12668 faces:43914 materials: 28 smoothgroups:0) ...
    ( 18.6672 sec |  18.6405 sec) Done.
  ( 18.6673 sec |  18.6671 sec) Finished importing: '/data/jjgd2e3f46f7cc1e8ba69a5e14689f7b974/models/model.obj'
Progress: 100.00%

但是,如果首先导入具有 ~12k 个顶点的相同对象,我会得到如下信息:

(  0.0001 sec |   0.0001 sec) Importing OBJ '/data/jjgd2e3f46f7cc1e8ba69a5e14689f7b974/models/model.obj'...
  (  0.0025 sec |   0.0023 sec) Parsing OBJ file...
    (  0.5541 sec |   0.5516 sec) Done, loading materials and images...
    (  0.5572 sec |   0.5547 sec) Done, building geometries (verts:12668 faces:43914 materials: 28 smoothgroups:0) ...
    (  1.0660 sec |   1.0635 sec) Done.
  (  1.0663 sec |   1.0662 sec) Finished importing: '/data/jjgd2e3f46f7cc1e8ba69a5e14689f7b974/models/model.obj'
Progress: 100.00%

这是我的代码:

#blenderClass.py
import bpy, math, timeit
import numpy as np

class Blender(object):
    def __init__(self):
        self.bpy = bpy
        self.scene = self.bpy.context.scene
        self.scene.render.use_sequencer = False

        # Some memory management
        self.scene.render.use_free_image_textures = True
        self.bpy.context.user_preferences.edit.undo_steps = 0
        self.bpy.context.user_preferences.edit.undo_memory_limit = 60
        self.bpy.context.user_preferences.edit.use_global_undo = False

    def setupScene(self):
        self.removeCamera()
        self.removeMesh()
        self.bpy.ops.object.camera_add(location=tuple(1, -0.5, 0.3))
        self.pointObjTo(self.scene.objects.active, (0.0, 0.0, 0.0)) # My objects are all centered on (0, 0, 0)

    def render(self, objPath):
        self.bpy.ops.import_scene.obj(filepath=objPath)
        self.removeMesh()
        self.removeDataBlocks()


    def removeDataBlocks(self, removeAll=False):
        # Removes unlinked data blocks and prevents memory leakage

        for block in self.bpy.data.meshes:
            if block.users == 0:
                self.bpy.data.meshes.remove(block)

        for block in self.bpy.data.materials:
            if block.users == 0:
                self.bpy.data.materials.remove(block)

        for block in self.bpy.data.textures:
            if block.users == 0:
                self.bpy.data.textures.remove(block)

        for block in self.bpy.data.images:
            if block.users == 0:
                self.bpy.data.images.remove(block)


    def removeMesh(self, layer = -1):
        for obj in self.scene.objects:
            if obj.type == 'MESH':
                obj.select = True
            else:
                obj.select = False
        self.bpy.ops.object.delete()


    def removeCamera(self):
        for obj in self.scene.objects:
            if obj.type == 'CAMERA':
                obj.select = True
            else:
                obj.select = False
        self.bpy.ops.object.delete()


    def pointObjTo(self, obj, xyzTarget):
        # This function operates directly on the input object (obj)
        from mathutils import Vector
        xyzTarget = Vector(xyzTarget)
        direction = xyzTarget - obj.location
        rot_quat = direction.to_track_quat('-Z', 'Y')
        obj.rotation_euler = rot_quat.to_euler()

这就是我 运行 代码的方式:

#main.py
import blenderClass import Blender
blender = Blender()
blender.setupScene()

objPaths = ['obj1.obj', 'obj2.obj', 'obj3.obj', 'obj4.obj']

for objPath in objPaths:
    blender.render(objPath)

不幸的是,我无法以精确的方式监控系统资源(我在服务器上 运行ning 这个)但我担心导入功能不会释放某些资源或不知何故内存越来越满。我尝试在我的台式计算机上将许多形状导入 Blender,并在手动删除网格后执行数据块删除功能。我的猜测是这样做可以将内存消耗减少到 10MB 左右,即使当我导入许多 3D 形状时它是 400MB。如果你想尝试上面的代码,也许一个简单的解决方案是使用基本形状,如球体、立方体等,然后 细分 它们,这样它们就会有很多顶点(也许 ~ 50-70k) 并将它们存储为 obj.我认为拥有大约 10-15 个 obj 文件应该可行。为我导入第 3 个或第 4 个对象后,事情开始变慢。

我不确定这是否相关,但我调用 Blender 函数的方式不是在 background 中调用它。相反,我手动将 Blender 2.79 编译为 Python 模块,并通过 import bpy 在我机器上安装的 Python 中导入它的 API。

虽然我相当确定删除数据块可以释放内存,但我也尝试过使用 Python 的垃圾收集器,但它没有帮助。

有谁知道我可能做错了什么?我很困惑...

虽然很奇怪,但如果我不导入带有标志的对象,导入函数看起来会导致长时间 运行 速度变慢。因此,用以下内容替换 obj 导入行将解决问题:

self.bpy.ops.import_scene.obj(filepath=objPath, split_mode="OFF")

不过我更愿意输入不相交的对象,但这暂时解决了导入速度变慢的问题。感谢 blenderartists 上的 doublebishop