Teigha Blog

BOM (Bill Of Materials) Manager is a service class that works with BOM tables, part references and BOM rows. All data held by BOM tables is stored in data containers that call data entries. There are three data entry types: DataEntry, DataEntryPart, and DataEntryBlock. DataEntryPart is connected with part references, and DataEntryBlock is connected with components.

Sometimes it is necessary to export a drawing to the PDF format as a grayscale or monochrome document. The usual way to do it is using plot styles: monochrome.ctb/stb and grayscale.ctb/stb.

Similar to Teigha Drawings, Teigha BIM also has visual styles for rendering elements in a DbView. However, with Teigha Drawings visual styles are separate elements in the database, and with Teigha BIM visual styles are part of the DbView.

In Teigha Mechanical, HoleChartOrigin is a part of the HoleChart complex entity. Creation of HoleChartOrigin is the first thing to do to make all components of HoleChart work correctly.

Introduction

Complex graphic scenes with a large number of elements are sometimes drawn slowly. In this case, dynamic graphic elements (such as cursors, grip/snap points, selection rectangles, user interface elements, and so on) are drawn slowly too because to correctly combine graphic scenes and dynamic graphic elements, the renderer must redraw all underlying scene elements.

When trying to extract image files from OLE2 frame entities, OdDbOle2Frame has the getCompoundDocument() method to get the streamBuf, but this is a stream of compound documents and not an image.

Many elements in Teigha BIM contain B-Rep geometries in GElement, which is a geometry cache of an element. However, B-Rep is not a universal format. Each product has a specific representation of B-Reps.

An overview of B-Reps and BIM specifics can be found in the documentation (login required).

Sometimes ODA members ask about exporting hatches and why a resulting .pdf file is very slow to open or why the quality of exported hatches is poor. This article explains a few things about hatches and exporting them to PDF.

There are three main types of hatches in .dwg files:

With Teigha you can create ACIS nurbs surfaces using a B-Rep Builder interface. Currently Teigha has two B-Rep Builder implementations: one in Teigha Kernel named AcisBrepBuilder and the other in Teigha BIM named BmBrepBuilder.

Rendering

FillPattern rendering is performed when rendering a corresponding shell if the OdGiFill traits attribute is supplied.