Point Clouds

Introduction

A point cloud is a set of data points in a three-dimensional coordinate system. In CHAI3D, these points are defined by X, Y, and Z coordinates, and often are intended to represent the external surface of an object.

Point clouds may be created by 3D scanners. These devices measure a large number of points on an object's surface, and often output a point cloud as a data file. The point cloud represents the set of points that the device has measured.

Point Cloud Objects

Point cloud object.

Similar to mesh objects, point cloud models use vertices to describe all the points that compose the cloud. A finger-proxy algorithm is also used to compute all the interaction forces between the haptic tool and the object. A collision detection must also be initialized after all points have been created.

using namespace chai3d;

// create a virtual mesh
cloud = new cMultiPoint();

// add object to world
world->addChild(cloud);

// load point cloud
cloud->loadFromFile("myPointCloud.obj");

// create collision detector
cloud->createAABBCollisionDetector(toolRadius);

// set point size for graphic rendering
cloud->setPointSize(5.0);

// set haptic stiffness
cloud->setStiffness(0.2 * maxStiffness, true);

// enable display list for faster graphic rendering
cloud->setUseDisplayList(true);