Bentley Descartes is an MDL application that allows MicroStation users to do many operations on rasters like editing, filtering, georeferencing, and so forth.

History

Bentley Descartes has become a member of the Bentley's product family when Bentley acquired HMR back in 2000. Before being acquired by Bentley, HMR was the research development group of Groupe Haut-Monts, a large aerial photography acquisition and post processing company from Quebec city. HMR has distinguished itself during the 90 for, amongst other things, being able to display very large images while using very little RAM memory. At the core of Bentley Descartes is the Imagepp library, also developed by HMR.

For MicroStation V8i, Bentley Descartes technologies and functionalities have been leveraged for binary imagery to supersede that which was included in Bentley I/RAS B.

What's new?

Bentley Descartes V8i (SELECTseries 4)

For Bentley Descartes V8i SELECTseries 4 the focus has been put on new functionalities to improve the visualisation, geographic localisation and object extraction from point cloud. As for the Scalable Terrain Model technology recently introduced in Bentley Descartes V8i SELECTseries 3 a couple of new functionalities have been developped for the purpose of doing analysis indirectly or directly on a Scalable Terrain Model.

Advanced Point Cloud Processing

Here is a summary of the new functionalities developed to help in processing information contained in a point cloud :

Template based linear feature extraction to improve the extraction of complex linear objects.
Semi-automatic line extraction to improve the ease of extracting linear feature from a point cloud.
Improve point cloud class management, including the ability to expand beyond the 13 classes defined for the LAS file format..
New configurable point cloud presentation styles similar to the MicroStation display styles.
New clip management system to improve point cloud manipulation and review.
New section management system to easily move throughout a point cloud along a specified path.
New geographic coordinate system related functionalities to cope with geo-located point cloud.
Enhanced fit cylinder functionality to improve the robustness and precision of cylinder extraction from a point cloud.

Scalable Terrain Model Analysis

Here is a summary of the new analysis related Scalable Terrain Model functionalities :

New viewshed analysis functionality to do high precision visibility analysis from a scalable terrain model.
New terrain model element creation tool to create a high precision terrain model from a scalable terrain model in order to do use the various analysis tool available on a terrain model element.
Enhanced thematic functionality to allow the visualisation of any kind of raster grid (e.g. : viewshed, demographic, etc...).

Bentley Descartes V8i (SELECTseries 3)

Bentley Descartes V8i SELECTseries 3 offers brand new tools and functionalities related to 3D city modeling and beyond. Most of the new tools and functionalities can be grouped in one of the two following categories : Point Cloud Processing and Scalable Terrain Modeling.

Point Cloud Processing

The functionalities for point cloud processing have been designed to help users to extract meaningful information from a point cloud for modeling and analysis purpose.

Here is a summary of the new functionalities available for point cloud processing.

Point Cloud Classification Editing
Point Cloud Line Draping
Point Cloud Advanced Export
Point Cloud Geometry Extraction
Point Cloud Visual Explorer
Point Cloud Smart Snap

More information on how to use effectively those functionalities are available on this page.

Scalable Terrain Model

A scalable terrain model is a terrain model (i.e. : DTM) that can cover a very large territory (e.g. : city, county, country) with low, medium and/or high precision terrain points.

Here is a summary of the new functionalities related to the scalable terrain model advancement.

Creation of a Scalable Terrain Model (i.e. .STM file) from various DTM data source (e.g. : point cloud, Bentley Civil DTM files, DEM raster, DGN element, etc...).
Can contain billions of DTM points.
Fast display.
Limited consumption of RAM.
High-Resolution draping of imagery (e.g. : satellite, aerial, urban plan, etc...) on the STM.
Export to the MicroStation terrain element.

More information on how to use effectively those functionalities are available on this page.

Bentley Descartes V8i (SELECTseries 2)

In Bentley Descartes V8i SELECTseries 2 a whole new set of tools has been added to texture 3D shapes with image data. The new texturing tools have been developped to fulfill the increasing demand of user to be able to create fully textured 3D city model.

The texturing tool includes:

Assign Shape to Image — This tool assigns a shape or shapes to an image or a number of images.
Warp Image to Area — Rectify an image to match the associated shape.
Stretch Image — Stretch images to match the shape upon which it has been mapped.
Convert to Advanced Texture — Convert images to Advanced Textures for higher resolution display.
Start Editing — Temporarily convert an Advanced Texture as a Raster Attachment to make it editable.
End Editing — Convert the Raster Attachment back to an Advanced Texture with its original parameters.
Convert to Texture — Convert images to standard textures for conventional rendering.

More information on those tools are available on the Bentley Descartes - Raster Texturing Wiki page.

Bentley Descartes V8i (SELECTseries 1)

The following describes the major changes in this version:

DEM Raster: It is now possible to attach Raster Surface (DEM) to Bentley Descartes. This images are displayed as 2D but it's possible assign color based on elevation, slope or aspect. Go to Bentley Descartes - DEM Raster Display for more information.
GeoRaster Support: Bentley Descartes now lets you connect to, and view, GeoRasters contained within Oracle Spatial databases. Go to Bentley Descartes - Raster From Oracle Database for more information.
Flood: This new tool is used to flood an area of a binary raster with the foreground color. See the flood section on [[Bentley Descartes - Raster Editing]] for more information.
Combine Images: This new tool is used to perform a logical operation on a selected area of two specified rasters and place the resulting data on a destination raster. This tool works on binary rasters only. See the combine section on [[Bentley Descartes - Raster Editing]] for more information.
Paste From File: When selecting this tool, the file selection dialog opens to select the raster file to be pasted. After the Open button is pressed, the remaining of the workflow is exactly as the standard Paste tool.
Define Seam Tool: Enhancements to this tool allow the feathering area to be defined interactively. In addition, only the top raster is modified so that the image can be detached and reattached without losing the mosaicing.
Merge: Enhancements have been made to the Merge tool to rasterize a view or a portion of a view to the clipboard.
Use Fence: A Use Fence option has been added to those editing tools that support a fence to define an area. When this option is turned on, the editing tool will work on all the raster attachments overlapped by the fence and will ignore the raster selection. The fence will always be treated as a fence clip which means that only the pixels overlapped by the fence will be edited.
Line Cap And Line Join Settings: A new section labeled Line Ends has been added to the Line Mapping Settings dialog. This section comprises two new settings labeled Line Cap and Line Join. These settings specify the line caps and line joins to be used in the merge and stamp operations.
Dynamic Rubber Band Display: The display of the dynamic rubber bands used in the Bentley Descartes editing tools have been enhanced so that they are easier to see.

Bentley Descartes V8i

Enhanced Raster Merging Tool
Editing of Oriented 3D Rasters
Binary Files Enhancements
Canvas Resizing
Dynamic Raster Snap
Addition Of Many Local Transform Tools
Vectorize Enhancements
Copy/Paste Integration with the Windows Clipboard
Raster Reprojection When Saving Raster
Many New Filters (Blur, Sharpen, Smooth, Detail, Edge Enhance and Find Edges)

Principal Functionality Groups

The following describes the principal functions of Bentley Descartes and provides links to the associated Wiki pages.

Raster Editing

Raster editing refers to the modification of the pixels' value of a raster and includes operation such as: touch-ups, stamping vectors, cutting, copying, pasting, transforming local areas, and masking color. Visit Bentley Descartes - Raster Editing for more information about the raster editing capabilities of Bentley Descartes.

Raster Enhancement

Raster enhancements refers to the set of functions that are capable of improving the general appearance of a raster such as refining or smoothing edges. For more information on the raster enhancement capabilities of Bentley Descartes, please visit Bentley Descartes - Raster Enhancement .

Raster Transformation

Raster transformation refers to the set of tools that are modify the shape and the content of a raster. Additional information can be found in this page: Bentley Descartes - Raster Transformation

Raster Registration

Raster registration refers to the set of functions that are used to specify a geospatial location for its raster. More information on the specifics of raster registration can be found on this page: Bentley Descartes - Raster Registration

Mosaic Rasters

Seamless mosaics can be created by utilizing specialized functions described on this page: Bentley Descartes - Mosaic Rasters

Raster Vectorization

Raster vectorization refers to a set of tools that are capable of detecting pixel formation in a raster and converting those pixels to a vector element. All this and more is described in the following link: Bentley Descartes - Raster Vectorization

Image Draping

While no longer a Descartes function, raster draping refers to ability of draping a raster onto a 3D surface. Please visit the following page for additional information: [[Bentley Descartes - Image Draping]]

DEM Raster Display

Bentley Descartes provides the ability to display the height field of DEM Rasters and is described on the following page: Bentley Descartes - DEM Raster Display

Raster From Oracle Database

Bentley Descartes provides the ability to read raster stored in an Oracle database, which is described on the following page: Bentley Descartes - Raster From Oracle Database

Miscellaneous Raster Functionalities

Bentley Descartes has many others functionalities which improve the task of working with raster. Those functionalities are described on the following page: Bentley Descartes - Miscellaneous Raster Functionalities