GeoMESH

GeoMESH

Win64, English

Femursoft
Application for Digital Elevation Models (DEM) and Triangulated Irregular Networks (TIN).

General Usage Instructions

  • The most important command of GeoMESH is GMESH. With this command you can select terrain points (Autodesk® AutoCAD® element POINT) and generate triangulated irregular networks - hereinafter referred to as “terrain meshes”. These terrain points and the new mesh are drawn on separate GeoMESH layers. A Delaunay algorithm is used to generate a terrain mesh. Alignments (AutoCAD element LINE) are considered when generating a mesh. The mesh adapts to these alignments. Maximum number of terrain points: see GMSETMAXDATA.
  • With the GMCONTOUR command, the selected GeoMESH mesh elements are interpolated, and the determined contour lines are drawn as polylines on a separate GeoMESH layer. For the interpolation, the value of the GeoMESH system variable GMSETCBASE is used as the base height and the value of the GeoMESH system variable GMSETCINKR is used for the height increment. If desired, the contour lines can also be drawn as splines (Switch: GMSETCSPLINE).
  • With the GMISOCONTOUR command, contour lines a filled with patterns. GMSETCOLORSCHEME controls the applied color scheme. With GMSETISO3DMODE set to OFF the patterns are drawn in the x-y-plane (constant z coordinate value of GMSETCBASE).
  • The GMSECTION command allows the construction of sections through selected GeoMESH mesh elements. A terrain section is created through the terrain mesh along a cutting line (AutoCAD element 3DPOLY, open, decurved). Section base is the value of the GeoMESH system variable GMSETCBASE. The terrain section is placed as a BLOCK in the x/y plane of the current user coordinate system (UCS). The insertion point and the scale factors in the x/y direction can be chosen freely.
  • New in GeoMESH Release 2.20: The GMTEXTURE command enables the projection of orthogonally acquired image data onto GeoMESH terrain meshes. The direction of projection is always perpendicular from the image plane to the terrain network, regardless of the coordinate system used. For a visually optimal result, it is advisable to set the AutoCAD system variables FRAME or IMAGEFRAME to 0. Caution: this command requires significant computer resources.
  • The GMVOLUME command enables the calculation of a volume difference between two terrain meshes. First, select the upper GeoMESH mesh elements (TOP) and then the lower GeoMESH mesh elements (BOTTOM). The accuracy of the calculation is controlled by the GeoMESH system variable GMSETVOLPREC. If GMSETVOLPREC is positive, the determined volume is drawn as a volume body on a separate GeoMESH layer.
  • The GMXYZIN command reads terrain points from a text file. File extension 'xyz' obliged. File format: x coordinate, y coordinate, z coordinate. As delimiter allowed: ':', ';', ',' or ‘ ‘. Any line beginning with '#' is treated as a comment line. Maximum number of terrain points: see GMSETMAXDATA. Caution: GeoMESH does not support text files with BOM (Byte Order Mark).
  • The GMLASIN command reads terrain points from a LAS file. File extension 'las' obliged. Supported file format: Version 1.0, 1.1, 1.2, 1.3 and 1.4. Note: GMLASIN read only the x, y, and z coordinates of any data record. For more information please visit: https://www.asprs.org. Maximum number of terrain points: see GMSETMAXDATA.
  • The GMESH2POINT command creates terrain points (AutoCAD elements POINT) from AutoCAD elements 3DFACE. Restriction: the 3DFACE elements must be triangles. With this command, it is possible to extract the terrain points from terrain meshes that were generated in other ways.
  • The GM3FACE2MESH command creates GeoMESH mesh elements from AutoCAD elements 3DFACE. Restriction: the 3DFACE elements must be triangles. With this command, it is possible to convert terrain meshes that were generated in a different way into GeoMESH mesh elements and thus avoid renewed mesh generations.

Commands

Ribbon/Toolbar Icon Command Command Description

GMABOUT

Displays status information about GeoMESH.

GMINFO

Displays status information about GeoMESH.

GMSTATUS

Displays status information about GeoMESH.

GMHELP

Displays a help page.

GMESH

Generates a terrain mesh of triangles using Delauney triangulation. Input: POINT elements (terrain points) and optionally LINE elements (alignments) are required. Alignment is used to define forced edges to which the terrain mesh will be confirmed. If GMSETUCSMODE is set to ON, the current UCS is used, otherwise always the WCS.

GMCONTOUR

Creates contour lines. Input: GeoMESH mesh elements are required. If GMSETCSPLINE is set to ON, the contour lines are displayed as splines. With GMSETCBASE the base height is set, with GMSETCINCR the height increment of the contour lines. If GMSETCINCR is less than zero, the maximum height difference of the selected mesh is divided by 50.

GMISOCONTOUR

Creates colored contour line patterns. Input: GeoMESH mesh elements are required. With GMSETCOLORSCHEME the color schema is set, with GMSETCBASE the base altitude and with GMSETCINCR the increment of the color gradation. If GMSETCINCR is less than zero, the maximum altitude difference of the selected mesh is divided by 50. If GMSETUCSMODE is set to ON, current UCS is used, otherwise always the WCS.

GMSECTION

Generates a terrain section to an existing terrain mesh. The terrain section is inserted as a block in the x-y plane of the current UCS. Input: GeoMESH mesh elements and afterward 3DPOLY elements are required. If GMSETUCSMODE is set to ON, the current UCS is used, otherwise always the WCS.

GMTEXTURE

New in Release 2.20: Applies an image on a terrain mesh. The image is always projected orthogonally onto the terrain mesh, regardless of the chosen coordinate system. Input: GeoMESH mesh elements and afterward one AutoCAD IMAGE element is required. Only one image can be applied per command operation. Set the AutoCAD system variable FRAME or IMAGEFRAME to 0 to make the image frames invisible for a natural view of the generated terrain simulation.

GMSURFACE

Calculates the area of the surface of a terrain mesh. Input: GeoMESH mesh elements are required.

GMVOLUME

Calculates the volume between two terrain meshes. Input: GeoMESH mesh elements are required, first the TOP mesh and second the BOTTOM mesh. If GMSETUCSMODE is set to ON, the current UCS is used, otherwise always the WCS. If GMSETVOLPREC is set to a positive value, the volume body is drawn on a separate GeoMESH layer.

GM3DFACE2MESH

Converts 3DFACE elements to GeoMESH mesh elements. Input: 3DFACE elements are required.

GMESH2POINT

Generates terrain points from 3DFACE elements. Input: 3DFACE elements are required. 3DFACE elements must be triangles.

GMXYZIN

Reads terrain points from an text file. File extension 'xyz' obliged. File format: x coordinate, y coordinate, z coordinate. As delimiter allowed: ':', ';', ',', or ' '. Any line beginning with '#' is treated as a comment line.

GMLASIN

Reads terrain points from an LAS file. File extension 'las' obliged. Supported file format: Version 1.0, 1.1, 1.2, 1.3 and 1.4. Note: GMLASIN read only the x, y, and z coordinates of any data record. For more information please visit: https://www.asprs.org.

GMSETCBASE

GeoMESH System Variable: Contains the base altitude for contour lines and colored contour line patterns. Any real value allowed. Default value is 0.0000.

GMSETCINCR

GeoMESH System Variable: Contains the altitude increment (contour lines) or the increment of the color gradation (contour line patterns). Any real value unequeal zero allowed. Default value is -1.0000.

GMSETCOLORSCHEME

GeoMESH System Variable: Contains the color scheme for contour line patterns of the command GMISOCONTOUR. GMSETCOLORSCHEME is a string of maximum 40 color codes. Any color codes has tree characters and iContains the color scheme for contour line patterns of the command GMISOCONTOUR. GMSETCOLORSCHEME is a string of maximum 40 color codes. Any color codes has tree characters and is defined like the AutoCAD Color Index (ACI) of the AutoCAD command COLOR. Any integer value between 1 and 255 allowed. Default value is '001002003004005006'.

GMSETCSPLINE

GeoMESH System Variable: If GMSETCSPLINE is set to ON, contour lines of the command GMCONTOUR are drawn as splines. The default value is OFF.

GMSETGROUPMODE

GeoMESH System Variable: If GMSETGROUPMODE is set to ON, program results are grouped in AutoCAD GROUPS (except alignments). The default value is ON.

GMSETISO3DMODE

GeoMESH System Variable: If GMSETISO3DMODE is set to OFF, colored contour line patterns of the command GMISOCONTOUR are drawn in x-y-plane with a constant z coordinate of GMSETCBASE. Default value is OFF.

GMSETMAXDATA

GeoMESH System Variable: Contains the maximum data records read from file or drawing by GeoMESH. Default value is 100000. Note: in TRIAL-Mode the value is limited to 100.

GMSETUCSMODE

GeoMESH System Variable: If GMSETUCSMODE is set to ON, the current UCS is used, otherwise always the WCS. The default value is OFF.

GMSETVOLPREC

GeoMESH System Variable: Contains the precision value for calculating the volume between to terrain meshes of the command GMVOLUME. Any negative or positive integer between 10 and 1000 is allowed. If the value is positive, a volume body is drawn on a separate GeoMESH layer. The default value is -100.

Installation/Uninstallation

The installer that was run when you downloaded this app/plugin from Autodesk App Store will start installing the app/plugin. OR, simply double-click the downloaded installer to install the app/plugin. You may need to restart your Autodesk product to activate the app/plugin. To uninstall this plugin, exit the Autodesk product if you are currently running it, simply rerun the installer and select the "Uninstall" button. OR click Control Panel > Programs > Programs and Features (Windows 10/11) and uninstall as you would any other system application.

Additional Information

The following important notes for all GeoMESH commands:

  • GeoMESH stores all GeoMESH system variables in the current drawing.
  • GeoMESH writes generated data in its own GeoMESH layers. Following default layer names and layer colors are used for this:
    - Terrain Points: Name: GM_POINT; Color: green
    - Alignments: Name: GM_ALIGNMENT; Color: magenta
    - Terrain Mesh: Name: GM_MESH; Color: grey (252)
    - Contours: Name: GM_CONTOUR; Color: yellow
    - Contour Line Patterns: Name: 'GM_ISOCONTOUR'; Color: white
    - Sections: Name: GM_SECTION; Color: cyan
    - Volumes: Name: GM_VOLUME; Color: blue; Status: frozen
    - Textures: Name: GM_TEXTURE; Color: white
  • All GeoMESH layer properties can be modified using standard AutoCAD layer commands. GeoMESH recognizes these and continues to use these modified layers.
  • Changed settings of GeoMESH system variables and GeoMESH layers can be saved in a separate AutoCAD file template. They are then available in modified form for other projects using this template.
  • By default, GeoMESH uses the AutoCAD world coordinate system (WCS) for all commands (GMSETUCSMODE = OFF). If you set the GeoMESH system variable GMSETUCSMODE to ON, the coordinates of the current user coordinate system (UCS) are used for all data read and written.
  • By default, GeoMESH groups all generated data (GMSETGROUPMODE = ON). Single groups are formed for the individual program results (e.g. terrain points, terrain meshes, contour lines, etc.). If the GeoMESH system variable GMSETGROUPMODE is set to OFF, the program results are not grouped.

Known Issues

  • GeoMESH is currently only available in English.
  • The algorithm used for mesh generation is numerically very robust and stable. However, numerical inaccuracies and thus mesh errors can occur if the points are very unevenly distributed, the area of the points is very large or very small, or mesh elements with a collinear character are created (all three points of a mesh element are almost or entirely on one line).
  • Caution: Command GMTEXTURE requires significant computer resources. 
  • Caution: Command GMXYZIN does not support text files with BOM (Byte Order Mark).
  • GeoMESH 2.2 and above does not support pointIDs any more.

Contact

Company Name: Femursoft
Support Contact: info@femursoft.com

Author/Company Information

Femursoft

Support Information

We look forward to hearing from you. Give us info, tricks, and hints about bugs. We try to answer and help as soon as possible. Thank you for making GeoMESH better. Write us at: info@femursoft.com

Visit femursoft.com for more information.

Version History

Version Number Version Description

2.2.0

- New command GMTEXTURE. Applies an ortho image on a terrain mesh. - Performance improvements. - GeoMESH does not support pointIDs anymore. - Minor bug fixes.

2.1.0

- New command GMISOCONTOUR. Generate contour line patterns. - New command GMLASIN. Reads terrain points from LAS-Files. - New command GMXYZIN. Reads terrain points from Text-Files. - Renaming command GMESH2POINTS to GMESH2POINT. - Deactivation command GMADDPOINTS due to numerical issues. - Minor bug fixes.

2.0.1

Initial Release.
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