问题起因：
在运行PointNet的可视化程序时，作者只提供了linux平台下的动态链接库程序源码,自己的windows平台下无法调用。发现是动态链接库的文件格式不对，遂学习如何将.so文件转换成.dll文件（PS：前提是你有文件的.cpp源码）
第一步新建C++动态链接库项目
将pch.h文件的内容改为如下：
#ifndef PCH_H#define PCH_H// 添加要在此处预编译的标头#include "framework.h"#endif //PCH_H//定义宏#ifdef IMPORT_DLL#else#define IMPORT_DLL extern "C" _declspec(dllimport) //指的是允许将其给外部调用#endif// 改为你所需要的链接库函数IMPORT_DLL void render_ball(int h, int w, unsigned char* show, int n, int* xyzs, float* c0, float* c1, float* c2, int r);
第二步：重写dllmain.cpp文件
// dllmain.cpp : 定义 DLL 应用程序的入口点。#include "pch.h"#include <cstdio>#include <vector>#include <algorithm>#include <math.h>using namespace std;struct PointInfo {int x, y, z;float r, g, b;};void render_ball(int h, int w, unsigned char* show, int n, int* xyzs, float* c0, float* c1, float* c2, int r) {r = max(r, 1);vector<int> depth(h * w, -2100000000);vector<PointInfo> pattern;for (int dx = -r; dx <= r; dx++)for (int dy = -r; dy <= r; dy++)if (dx * dx + dy * dy < r * r) {double dz = sqrt(double(r * r - dx * dx - dy * dy));PointInfo pinfo;pinfo.x = dx;pinfo.y = dy;pinfo.z = dz;pinfo.r = dz / r;pinfo.g = dz / r;pinfo.b = dz / r;pattern.push_back(pinfo);}double zmin = 0, zmax = 0;for (int i = 0; i < n; i++) {if (i == 0) {zmin = xyzs[i * 3 + 2] - r;zmax = xyzs[i * 3 + 2] + r;}else {zmin = min(zmin, double(xyzs[i * 3 + 2] - r));zmax = max(zmax, double(xyzs[i * 3 + 2] + r));}}for (int i = 0; i < n; i++) {int x = xyzs[i * 3 + 0], y = xyzs[i * 3 + 1], z = xyzs[i * 3 + 2];for (int j = 0; j<int(pattern.size()); j++) {int x2 = x + pattern[j].x;int y2 = y + pattern[j].y;int z2 = z + pattern[j].z;if (!(x2 < 0 || x2 >= h || y2 < 0 || y2 >= w) && depth[x2 * w + y2] < z2) {depth[x2 * w + y2] = z2;double intensity = min(1.0, (z2 - zmin) / (zmax - zmin) * 0.7 + 0.3);show[(x2 * w + y2) * 3 + 0] = pattern[j].b * c2[i] * intensity;show[(x2 * w + y2) * 3 + 1] = pattern[j].g * c0[i] * intensity;show[(x2 * w + y2) * 3 + 2] = pattern[j].r * c1[i] * intensity;}}}}// 具体内容改为你的文件内容
