假设。从 Wavefront Obj 文件导入模型后奇怪的顶点坐标答案

【问题标题】：Assimp. Weird vertices coordinates after importing a model from Wavefront Obj file假设。从 Wavefront Obj 文件导入模型后奇怪的顶点坐标
【发布时间】：2021-11-06 23:59:32
【问题描述】：

我在搅拌机中创建了一个简单的单位大小的平面并将其导出到 .obj 文件中，内容是这样的

# Blender v2.93.3 OBJ File: ''
# www.blender.org
mtllib plane.mtl
o Plane
v 1.000000 -1.000000 0.000000
v -1.000000 -1.000000 0.000000
v 1.000000 1.000000 0.000000
v -1.000000 1.000000 0.000000
vt 0.000000 0.000000
vt 1.000000 0.000000
vt 1.000000 1.000000
vt 0.000000 1.000000
vn 0.0000 0.0000 -1.0000
usemtl None
s off
f 1/1/1 2/2/1 4/3/1 3/4/1

当我用 assimp 导入它时

unsigned flags = aiProcess_Triangulate | aiProcess_OptimizeMeshes |
                     aiProcess_JoinIdenticalVertices | aiProcess_SortByPType |
                     aiProcess_CalcTangentSpace /*|aiProcess_FlipWindingOrder*/;
const aiScene * scene = importer.ReadFile(path, flags);
for (int i = 0; i < scene->mNumMeshes; ++i)
    {
        const aiMesh * mesh = scene->mMeshes[i];
        for (int j = 0; j < mesh->mNumVertices; ++j)
        {
            const aiVector3D & vertex = mesh->mVertices[j];
            model->vertices.emplace_back(vertex.x, vertex.y, vertex.z);
        // ...

它给了我奇怪的结果

x = {double} -0.007812501848093234
y = {double} -0.0078125
z = {double} 1.5873523201947252E-314

x = {double} 0.0078125055733835325
y = {double} 0.0078125
z = {double} 5.2635442471208903E-315

x = {double} 2.1053526862322168E-314
y = {double} -3.0421935264696467E-310
z = {double} 0

x = {double} 0
y = {double} 0
z = {double} 0

我期望值从 1 到 -1，就像它们在 .obj 文件中一样
我也试过传0而不是flags，结果是一样的

【问题讨论】：

标签： c++ assimp

【解决方案1】：

问题是因为我定义了ASSIMP_DOUBLE_PRECISION，这是原因

【讨论】：