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我试图创建二进制PLY文件,用下面的标头输出帘布层的文件:C++如何以二进制格式
ply
format binary_little_endian 1.0
element vertex 43000
property float x
property float y
property float z
property float nx
property float ny
property float nz
property uchar red
property uchar green
property uchar blue
end_header
我有以下重载函数写为二进制(另一示例性验证) :
inline void write_fbin(std::ofstream &out, float val) {
out.write(reinterpret_cast<char*>(&val), sizeof(float));
}
inline void write_fbin(std::ofstream &out, unsigned char val) {
out.write(reinterpret_cast<char*>(&val), sizeof(unsigned char));
}
我写的顶点信息如下:
write_fbin(ofstr, static_cast<float>(point.x));
write_fbin(ofstr, static_cast<float>(point.y));
write_fbin(ofstr, static_cast<float>(point.z));
write_fbin(ofstr, static_cast<float>(point.n_x));
write_fbin(ofstr, static_cast<float>(point.n_y));
write_fbin(ofstr, static_cast<float>(point.n_z));
write_fbin(ofstr, static_cast<unsigned char>(point.r));
write_fbin(ofstr, static_cast<unsigned char>(point.g));
write_fbin(ofstr, static_cast<unsigned char>(point.b));
其中point
是类型的结构
struct DensePoint {
float x, y, z;
float n_x, n_y, n_z;
unsigned char r, g, b;
};
这不起作用并产生无效的层文件。但是,如果我使用相同的代码(更改标题)生成ASCII版本,那么
ofstr
<< point.x << ' '
<< point.y << ' '
<< point.z << ' '
<< point.n_x << ' '
<< point.n_y << ' '
<< point.n_z << ' '
<< static_cast<int>(point.r) << ' '
<< static_cast<int>(point.g) << ' '
<< static_cast<int>(point.b) <<
'\n';
这很好。什么可能是错的?
也许我需要在每个顶点的二进制格式的末尾引入一个换行符?
'end_header'后面是否有行尾? – dkg
是的,二进制和ASCII二进制 – manatttta
根据http://www.cs.virginia.edu/~gfx/Courses/2001/Advanced.spring.01/plylib/Ply.txt你的数据是否有正确的字节数?你可以使用固定长度类型作为uint8,等等......以确保 – dkg