Ply 3D files generation

Brief Description

Generate a 3D Ply file from a DEM and a color image.

Tags

Geometry

Long Description

The application converts an image containing elevations into a PLY file, which is a file format to store 3D models. This format is adpated for visualization on software such as MeshLab [2] or CloudCompare [3]

This application is part of the stereo reconstruction framework. The input data can be produced by the application DisparityMapToElevationMap.

There are two types of supported input images:
* A DEM image, with a ground projection, containing elevation values. Each elevation value can be considered as a 3D point.
* A 3D grid image, containing 5 bands (the first 3 are the 3D coordinates of each point, the 5th is a validity mask where valid values are larger or equal to 1)

The user shall also give a support image that contains color values for each 3D point. The color values will be embedded in the PLY file.

Parameters

The input DEM image (indem): The image should be either a projected DEM or a 3D grid containing 3D point coordinates and a validity mask.
Conversion Mode (mode):
- DEM (dem): DEM conversion mode (the projection information of the DEM is used to derive the X and Y coordinates of each point)
- 3D grid (3dgrid): 3D grid conversion mode

Map Projection (map): Defines the map projection to be used.
- Universal Trans-Mercator (UTM) (utm): A system of transverse mercator projections dividing the surface of Earth between 80S and 84N latitude.
  - Zone number (map.utm.zone): The zone number ranges from 1 to 60 and allows defining the transverse mercator projection (along with the hemisphere)
  - Northern Hemisphere (map.utm.northhem): The transverse mercator projections are defined by their zone number as well as the hemisphere. Activate this parameter if your image is in the northern hemisphere.
- Lambert II Etendu (lambert2): This is a Lambert Conformal Conic projection mainly used in France.
- Lambert93 (lambert93): This is a Lambert 93 projection mainly used in France.
- WGS 84 (wgs): This is a Geographical projection
- EPSG Code (epsg): This code is a generic way of identifying map projections, and allows specifying a large amount of them. See www.spatialreference.org to find which EPSG code is associated to your projection;
  - EPSG Code (map.epsg.code): See www.spatialreference.org to find which EPSG code is associated to your projection

The input color image (incolor): If the color image has 4 bands it will be interpreted as Red, Green, Blue, NIR. In other cases, only the first one is used (gray scale colors). The color values are expected in the range 0 - 255, and will be embedded with each 3D point of the PLY file.
The output Ply file (out): The output Ply file will contain as many 3D points as pixels in the input DEM.
Load otb application from xml file (inxml): Load otb application from xml file
Save otb application to xml file (outxml): Save otb application to xml file

Limitations

The input DEM image has to entirely fit into memory.

Authors

OTB-Team