GLuint posLength = sizeof(PointStruct) * PointCloudData.size(); correct
GLuint posLength = sizeof(PointCloudData) ; wrong
glBufferData(GL_ARRAY_BUFFER, posLength, &PointCloudData[0], GL_STATIC_DRAW);
GLuint posLength = sizeof(PointStruct) * PointCloudData.size(); correct
GLuint posLength = sizeof(PointCloudData) ; wrong
glBufferData(GL_ARRAY_BUFFER, posLength, &PointCloudData[0], GL_STATIC_DRAW);