[Point-clouds process]Real Data Processing

This is a software system making it possible to reconstruct 3D objects from point-clouds. The system consists of four programs, thinning out point-clouds, edge detection from points, connecting points with triangles and graphic editor for points and triangles.
The point number of clouds including overhanging captured by scanning systems is decreased if necessary, and points are connected automatically with triangles. These triangles are edited graphically and cross-sections etc are found.

Reconstructions of various 3D models from the points of 3D data (mechanical objects, geographical features, ocean floors, architectures, medical data like CT, etc) are the applications.

The followings are descriptions of programs together with images.
Data for descriptions are offered by Riegl Japan Co.Ltd. Thanks for their cooperations.

The next image is a diagram of Point-cloud Process System.
Clicking the areas where numbers are indicated links their functional descriptions.
The descriptions are in procedural order.

1.Measured Points:

  • Laser scanning systems usually have DXF outputs of captured data. The next image is of all the point-clouds after reading DXF point data(1,580,000points) into our graphic program, called NfDesign. Back to the System Diagram

2.Graphic Process: NfDesign
This program is in charge of every graphic process by human operations. The following functions are some of features being used for processing points and polygons.
Please refer to the page, 3DCGModerer for further information. Back to the System Diagram

  • Input of Point-clouds and Display, Selection of Points and Output

  • Input of Connected-triangles(polygon) and Display at Arbitrary Viewpoints

  • Smoothening Polygon(s) without Increasing Triangle Number of Polygon(s) Process Samples

  • Reducing Triangle Number of Polygon(s), Preserving Shapes as much as possible Process Sample

  • Zebra Mapping Sample Image

  • Fill Open Area with Polygons

  • Move Vertices, Move Vertices on plane, Move Vertices on Line, Snap Vertex on Vertex

  • Align Surfaces

  • Cross-sections, NURBS-fitting for Section-lines

  • Generation of Polygon(s) inside of closed Section-lines Sample Image

  • Generation of Curves from Section-lines

3.Edge Detection: EdgePS

  • Measured point data is an input and the program outputs edge points depending on the set parameter. The parameter decides what part of points are edges.
    Please refer to the page, here for processing mechanical part and variation effect of the parameters.
  • Measured points file is the input and the program outputs edge points. The next image is the edge points of 140,000 displayed with Graphics. Back to the System Diagram

4.Thinning : SimpPS

  • This is the program thinning out 3D points. The target number of points and effective ratio(change/interval) set in the dialogue result in thinning.
  • Measured points file is the input and the program outputs points after thinning out. The ratio 100% (interval only) is set in the dialogu and 100,000 points are output here. Back to the System Diagram

5.Points before Triangles

6.Triangles: 3DChain

  • This is the program changing point-clouds into triangles.
  • The program divides points automatically and enormous points are processed effectively.
  • The graphic program displays triangles generated by this program. Input points are merged to 240,000 consisting of 100,000 points after thinning out and edge points after edge detection. Link to CG //Back to the System Diagram

CG Image:

  • The next is a rendering image after texture mapping and additional processing.
    The last is a rendering image where stone walls come from measured points and other objects are created referring to the polygons from measured points.