Tutorial: Getting Started with AutoCAD

Liz Sanderson
Liz Sanderson
  • Updated

FME Version

  • FME 2018.x

Introduction

Autodesk AutoCAD transformations are some of the most commonly utilized transformations in FME. There are four main formats that FME uses to read and write AutoCAD drawing files; for more specific information on which format to use, please refer to the article AutoCAD DWG - What format should I use? .

For the purposes of this beginner tutorial, we will focus on the AutoDesk AutoCAD DWG/DXF (ACAD) format. To better understand how FME represents and translates AutoCAD drawing files, it is first worth looking at the basic components of a DWG file. When adding a DWG reader to your FME workspace, you will notice that there are a large number of reader parameters to choose from. While we will discuss when to use certain parameters later in this tutorial, let's first examine some of the more common terms that will be used throughout these articles.
 

Terminology

Entities

What is meant by 'Entities' in AutoCAD? An AutoCAD entity represents a single drawn object in a DWG. An entity may be a block, line, point, text, etc. This term is important to keep in mind when discussing DWG transformations, as many of the reader parameters are centered on how you want to read and group entities. How you choose to group your entities will also affect what will become an FME feature type during translation.
 

Layers

AutoCAD layers are user-defined groupings of entities that may have user-defined style and format characteristics as well as references to other layers (xrefs). In FME, layers are the default entity grouping in the reader parameters.
 

Attributes

AutoCAD attributes can only be attached to block entities in the form of a label or a tag. In FME, this attribute information can be exposed using certain reader parameters and workflow modifications. For information on how to extract this attribute information during translation (such as converting these attributes to shapefile), please see the transformation tutorial on transforming DWG to SHP.
 

Extended Entity Data

Also known as xdata. This is a piece of application-driven information that users can attach to any given entity. This is not the same as an attribute, but rather a small snippet of information (<=16Kb) important to that specific entity (such as steel beam density). Extended entity data can be exposed by selecting the 'Read Interpreted Extended Entity Data' option in the DWG/DXF reader parameters, but how this data is interpreted depends on the type of extended entity data (e.g. text, integer) and which other reader parameters are selected.
 

Blocks

AutoCAD blocks are collections of entities such as lines, points, text that are combined together to form one single block entity. Blocks save a CAD operator's time by providing the ability to re-use the same 'sub-drawing' (such as a door, tree, lamp) over and over on different layers or even drawings (with the correct reference information in place) without having to redraw the element each time it is required. In FME and AutoCAD, block entities are saved as 'inserts', which both programs interpret as points. These inserts reference block definitions that dictate what is to be drawn at the insert location. In FME, a user can explode a block into its entity components by selecting 'Explode Blocks into Entities' in the reader parameters. More information on block handling is available later in this tutorial in Basic DWG Block Handling Example: Exploding Block Entities (DWG to PDF).
 

Learning Objectives

  • View and inspect AutoCAD DWG Files, including grouping entities and handling blocks
  • Carry out DWG to DGN translation
  • Carry out Esri Shapefile (SHP) to DWG translation
  • Explode block entities in DWG translations
  • Preserve block entities in DWG translations

 

Articles

Viewing and Inspecting AutoCAD DWG Files:Grouping Entities

In this article, we examine the different ways you can modify the Group Entities reader parameters to tailor your workspace and data inspection for your needs.
 

Viewing and Inspecting AutoCAD DWG Data: Handling Blocks

In this article, we examine the difference between exploding blocks and not exploding blocks when reading DWG data.
 

How to Convert DWG to DGN (AutoCAD to Microstation)

This example shows how to perform a translation from DWG to DGN (AutoCAD to Bentley Microstation Design) format.
 

How to convert SHP to DWG (Esri Shapefile to AutoCAD)

This example demonstrates transforming some City of Vancouver postal code data from Esri shapefile to AutoCAD DWG and storing the attributes as Extended Entity data.
 

Basic DWG Block Handling Example: Exploding Block Entities (DWG to PDF)

In this article, we examine what happens when you choose to explode block entities in FME, and when that decision might make sense for your workflow. This article also links to an example of working with exploded blocks in a DWG to PDF translation.
 

Basic DWG Block Handling Example: Preserving Block Entities (DWG to SHP)

In this article we look at what happens if you choose to not explode your blocks, and when that option might be best for your workflow. This article also links to an example of working with blocks in a DWG to SHP translation.

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