# Potree Core

 - This project is based on Potree V1.6.
 - Potree is a web based pouint cloud visualizer project created by Markus Schütz.
 - This project contains only the main parts of the potree project adapted to be more easily used as a independent library (I have only adapted code from the original repository).
 - Support for pointclouds from LAS, LAZ, Binary files and Grehound server.
 - Point clouds are automatically updated, frustum culling is used to avoid unnecessary updates (better update performance for multiple point clouds).
 - Supports logarithmic depth buffer (just by enabling it on the threejs renderer), useful for large scale visualization.



### How to use
 - Download the custom potree build from the build folder or add it to your project using NPM.
    - https://www.npmjs.com/package/potree-core
 - Include it alonside the worker folder in your project (can be found on the source folder).
 - Download threejs from github repository.
    - https://github.com/mrdoob/three.js/tree/dev/build
 - The build is a ES module, that can be imported to other projects, it assumes the existence of THREE namespace for threejs dependencies.



### Demo
 - Live demo at https://tentone.github.io/potree-core/
 - Contains the same model multiple times stored in different formats.
 - Double click the models to raycast the scene and create marker points.

<img src="https://raw.githubusercontent.com/tentone/potree-core/master/screenshot.png" width="700">


### Example
 - Bellow its a fully functional example of how to use this wrapper to load potree point clouds to a THREE.js project

```javascript
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(60, 1, 0.1, 10000);

var canvas = document.createElement("canvas");
canvas.style.position = "absolute";
canvas.style.top = "0px";
canvas.style.left = "0px";
canvas.style.width = "100%";
canvas.style.height = "100%";
document.body.appendChild(canvas);

var renderer = new THREE.WebGLRenderer({canvas:canvas});

var geometry = new THREE.BoxGeometry(1, 1, 1);
var material = new THREE.MeshBasicMaterial({color: 0x00ff00});
var cube = new THREE.Mesh(geometry, material);
scene.add(cube);

var controls = new THREE.OrbitControls(camera, canvas);
camera.position.z = 10;

var points = new Potree.Group();
points.setPointBudget(10000000)
scene.add(points);

Potree.loadPointCloud("data/test/cloud.js", name, function(data)
{
	var pointcloud = data.pointcloud;
	points.add(pointcloud);
});

function loop()
{
	controls.update();
	renderer.render(scene, camera);
	requestAnimationFrame(loop);
};
loop();

document.body.onresize = function()
{
	var width = window.innerWidth;
	var height = window.innerHeight;
	renderer.setSize(width, height);
	camera.aspect = width / height;
	camera.updateProjectionMatrix();
}
document.body.onresize();
```



### API Reference

 - The project has no generated documentation but bellow are some of the main configuration elements.
 - A example can be found in the repository `index.html` file.



##### Potree.BasicGroup

- Container that stores point cloud objects and updates them on render.
- The container supports frustum culling using the point cloud bouding box.
- Automatically stops updating the point cloud if out of view.
- This container only support pointColorType set as RGB, pointSizeType set as FIXED and shape set as SQUARE.



##### Potree.Group

- Complete container with support for all potree features.
- Some features require support for the following GL extensions

   - EXT_frag_depth, WEBGL_depth_texture, OES_vertex_array_object

   

##### Potree.loadPointCloud

- Method to load a point cloud database file
- `Potree.loadPointCloud(url, name, onLoad)`



##### Potree.PointCloudMaterial

- Material used by threejs to draw the point clouds, based on RawShaderMaterial
- shape
   - Defines the shape used to draw points
      - Potree.PointShape.SQUARE
      - Potree.PointShape.CIRCLE
      - Potree.PointShape.PARABOLOID
- pointSizeType
   - Defines how the point cloud points are sized, fixed mode keeps the same size, adaptive resizes points accordingly to their distance to the camera 
   - Possible values are
      - Potree.PointSizeType.FIXED
      - Potree.PointSizeType.ATTENUATED
      - Potree.PointSizeType.ADAPTIVE
- pointColorType
   - Defines how to color the drawn points
   - Possible values are
      - Potree.PointColorType.RGB
      - Potree.PointColorType.COLOR
      - Potree.PointColorType.DEPTH
      - Potree.PointColorType.HEIGHT
      - Potree.PointColorType.INTENSITY
      - Potree.PointColorType.INTENSITY_GRADIENT
      - Potree.PointColorType.LOD
      - Potree.PointColorType.POINT_INDEX
      - Potree.PointColorType.CLASSIFICATION
      - Potree.PointColorType.RETURN_NUMBER
      - Potree.PointColorType.SOURCE
      - Potree.PointColorType.NORMAL
      - Potree.PointColorType.PHONG
      - Potree.PointColorType.RGB_HEIGHT
- logarithmicDepthBuffer
   - Set true to enable logarithmic depth buffer
- weighted
   - If true points are drawn as weighted splats
- treeType
   - Defines the type of point cloud tree being drawn by this material
   - This should be automatically defined by the loader
      - Potree.TreeType.OCTREE
      - Potree.TreeType.KDTREE

 - Potree.PointCloudTree
    - Base Object3D used to store and represent point cloud data.
    - These objects are created by the loader




### Notes
 - Since potree-core is mean to be used as library and not as a full software as potree some features are not available.
 - EDL shading is not supported by potree core (might be added later).

- GUI elements were removed from the library
  - PotreeViewer
  - Controls, Input, GUI, Tools
  - Anotations, Actions, ProfileRequest
  - Potree.startQuery, Potree.endQuery and Potree.resolveQueries
  - Potree.timerQueries
  - Potree.MOUSE, Potree.CameraMode
  - PotreeRenderer, RepRenderer, Potree.Renderer
    - JQuery, TWEEN and Proj4 dependencies



### Building
 - The project can be build running the commands `npm install` and `npm run build`.



### Point Clouds
 - Use the Potree Converter tool to create point cloud data from LAS, ZLAS or BIN point cloud files
    - https://github.com/potree/PotreeConverter/releases