A small utility that converts .asc point cloud file into binary-LE .ply file.

asc2ply.cpp

#include <deque>
#include <fstream>
#include <iostream>
#include <memory>

namespace
{
    struct Point
    {
        float x, y, z;
        unsigned char r, g, b;
    };

    void convert_asc_to_ply(std::istream& input, std::ostream& output)
    {
        std::deque<Point> points;

        while (input.good())
        {
            float x, y, z, w;
            int r, g, b;

            input >> x >> y >> z >> r >> g >> b >> w;

            points.push_back(Point{
                .x = x, .y = y, .z = z,
                .r = (unsigned char)r,
                .g = (unsigned char)g,
                .b = (unsigned char)b
            });
        }

        output << "ply" << std::endl;
        output << "format binary_little_endian 1.0" << std::endl;
        output << "element vertex " << points.size() << std::endl;
        output << "property float x" << std::endl;
        output << "property float y" << std::endl;
        output << "property float z" << std::endl;
        output << "property uchar red" << std::endl;
        output << "property uchar green" << std::endl;
        output << "property uchar blue" << std::endl;
        output << "end_header" << std::endl;

        for (auto p : points)
        {
             output.write(reinterpret_cast<const char*>(&p.x), sizeof(float) * 3);
             output.write(reinterpret_cast<const char*>(&p.r), sizeof(unsigned char) * 3);
        }
    }
}

int main(int argc, char* argv[])
{
    std::unique_ptr<std::istream> ifs;
    std::unique_ptr<std::ostream> ofs;

    if (argc > 1)
        ifs = std::make_unique<std::ifstream>(argv[1]);

    if (argc > 2)
        ofs = std::make_unique<std::ofstream>(argv[2]);

    convert_asc_to_ply(ifs ? *ifs : std::cin, ofs ? *ofs : std::cout);

    return 0;
}