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Creating Surfaces From Point Cloud Data
The Surface Manager
You can create a raster-based
surface (page 2076) from point cloud data in either
GeoTIFF or ESRI ASC format. After you have created your surface, you can
view, theme, and analyze it like any other raster-based surface in AutoCAD
Map 3D. For more information on working with raster-based surfaces, see
Adding Rasters and Surfaces (page 437), Analyzing Raster-Based Surfaces (page
1186), and
Styling Raster Images (page 671).
The
Surface Manager (page 1898) also allows you to assign multiple input files
to a single surface file using merge groups. You might want to create a merge
group in order to apply a spatial filter across several input files, for example.
The source files for a merge group must use the same coordinate system.
Before you create a surface from point cloud data, ensure that the data is
projected in a local coordinate system that uses feet or meters for vertical
units. If the source data is not in a local coordinate system, you can either
assign a local system to it in the
Point Cloud Manager (page 1897), or assign a
local system to your drawing. Assigning a local coordinate system to the point
cloud data using the Point Cloud Manager will give you better performance.
NOTE AutoCAD Map 3D automatically resamples the raster-based surfaces when
you zoom in and out in your map. However, surfaces do not display well at some
zoom levels, especially at small view scales. To improve the appearance of the
surface in your map, you can resample the raster image by right-clicking the raster
layer in the Display Manager and selecting Resample Raster. If resampling the
surface does not improve the image quality, view the grid at a larger view scale.
Creating Surfaces From Point Cloud Data | 1021