ESP-r & 3rd Party Software

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Overview of third party software

ESP-r makes use of third party software to assist in the simulation process. Some of these are public domain and are distributed (without warranty) with the ESP-r system. Others are from proprietary and must be acquired from the relevant company.

ESP-r may be one of a group of tools used to assist the design process. The following is a brief discussion of some of the applications which ESP-r cooperates with.

• 3D CAD packages
• Presentation/Graphing packages
• Import/Export
• Text & image editors

3D modellers

While the Project Manager provides facilities for defining the geometry of a problem, users may find that they prefer to use other CAD programs to create the form of the problem and then import such data for annotating and further development. Currently files from the 3rd party CAD packages XZIP and AutoCAD V12 are supported.

The package XZIP has a product model similar to that of ESP-r and the transfer of information between these two applications is reasonably robust. At the current time it is recommended that users do not use the facilities of XZIP to insert windows and doors into zone enclosures, but use the facilities of ESP-r.

NOTE: that users should not attempt to edit or specify geometry in an XZIP 3D display, only in a 2D display.

The exchange of information between ESP-r and AutoCAD is by way of a DXF file filter. Unlike XZIP, AutoCAD has a substantially different product model and it is necessary for the user to constrain their use of AutoCAD to a subset of entities and to make use of its LAYER conventions to define surfaces related to different zones.

In the case of exporting geometry from ESP-r to AutoCAD the following conventions are used:

LAYERS

In order to associate geometric CAD entities with thermal zone enclosures (a concept absent in AutoCAD but crucial to simulation) a convention has been adopted that each of the CAD entities related to a particular zone should be placed in specific LAYERS.

thermal zones

Each thermal zone enclosure it placed in a separate named LAYER. Where there are opaque and transparent surfaces the LAYERS are further subdivided.

surfaces

Each surface in a thermal zone is converted to a 3DFACE if it contains 3 or 4 sides or a 3DPOLY if more complex. It is intended to make use of PFACE in the future.

shading obstructions

Where there are obstructions associated with a zone an additional LAYER (one per zone with obstructions) is created. Obstructions are represented as a BLOCK entity. There is one unit (dimensions of 1x1x1 Unit) and the each reference contains the scaling factors and rotations to be equivalent to the obstruction.

In the case of importing geometry from AutoCAD (or other CAD packages which produce DXF files) the following conventions are used:

LAYERS

In order to associate geometric CAD entities with thermal zone enclosures (a concept absent in AutoCAD but crucial to simulation) a convention has been adopted that each of the CAD entities related to a particular zone should be placed in specific LAYERS. The name of the layer will become the name of the thermal zone. An additional convention is that opaque elements are placed in the LAYER with the zone name (say for example OFFICE_A) and the transparent elements in a LAYER named TRN_OFFICE_A

BLOCK

This entity is typically used to represent shading obstructions.

The following is a partial list of the entities which can be exchanged.

3DFACE

Because simulation enclosures are surfaces bounded by a polygon representation and equivalent representation is a 3DFACE. AutoCAD restricts a 3DFACE to 3 or 4 edges and so a number of such faces may be required to compose enclosures of any degree of complexity.

3DPOLY

This entity is converted into a surface in the simulation environment. The number of edges must be between 3 and 20.

3DMESH

This entity has no meaning for a simulation environment and is skipped.

ARC

This entity has no meaning for a simulation environment and is skipped.

BLOCK

This entity is typically used to represent shading obstructions.

CIRCLE

This entity has no meaning for a simulation environment and is skipped.

ELLIPSE

This entity has no meaning for a simulation environment and is skipped.

LINE (2D or 3D)

This entity has no meaning for a simulation environment and is skipped.

PFACE

This is not yet supported.

POINT

This entity has no meaning for a simulation environment and is skipped.

SOLID

This entity has no meaning for a simulation environment and is skipped.

TEXT

This entity has no meaning for a simulation environment and is skipped.

Presentation quality graphing programs

While the results analysis facility presents information in many different graphical formats, some users require a higher display quality than that provided with the inbuilt facilities. To support this results may be exported in a format compatible with 3rd party graphing applications. The export formats currently supported are:

  xmgrace - public domain graphing and statistics analysis
  viewer - hidden line perspective views

Text & Image editing facilities

It is often necessary to capture images from a workstation screen for inclusion in a document. Because such facilities are tied to the particular window manager used on a given workstation most systems will also provide image editing and printing facilities.