Praca Dyplomowa - Photogrammetry and Remote Sensing - AGH

THEORETICAL BACKGROUND
opportunities, because the model may be rotated, but also, the light source and material may
be changed as well, and the file may be open in Adobe Reader. Other opportunity is creation
of video file, key frames may be chosen by the user, and short video may be exported.
Simplified workflow, with listed operations, in modelling and visualising from 3D point cloud
to final product is shown in Table 2.1.
Table 2.1 Simplified workflow for modelling: from point cloud to final model
One regular 3D point cloud
Filtering of point cloud Removing noise, occluded point
Smoothing algorithms
Some manual edition if needed
Filling holes (if exists)
Reducing number of points
Triangulation Generation of TIN, 3D surface
Filtering of TIN (if needed) Filling holes (if exists)
Smoothing algorithms
Removing spikes
Reparation of surface (topology, intersections, etc.)
Reducing number of triangles
Model of light and reflection (visualisation)
Light source
Type of light
Place of light
Illumination
Reflection
Texture mapping Real texture from photographs
Or unreal texture
Some additional visual, display settings Depending on the software
Export output 2D images
3D files, for example:
3D PDF, VRML, etc.
Video files
2.4.1 Solid triangulated surfaces
Collection of 3D points, which create vertices that are connected with each other and creates
triangles (TIN). This type usually defines the volume of the object they represent, like a rock
etc. From this collection 3D models may be created usually in software using proper
algorithms. This method is mainly used in connection to data derived from 3D scanning or
photogrammetry, where point clouds can be gained. This method is used for shapes, forms,
where exact shape of the object is hard to define, like rectangles, shapes which are easy to
define may help to improve the model. Curves easy to define may be used as break lines and
have impact on created surface.
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