Through the Interface

Getting to know the Project Draw API

Last week David Falck, over at the Autodesk Labs team, provided me with an API key to have a play with the API to Project Draw. This post documents what I did, and how it all worked. Note: I'm not actually doing any coding whatsoever in this post: I used the handy API test page provided by the Autodesk Labs team, and so didn't need to write a single line of code. So, first of all, you'll need an API key. Here's the one I got from the Draw team: th1SIsnOTreAlLyMyapIkeyOfCourSE Just kidding. I've changed the above key for... Read more →

Turtle fractals in AutoCAD using .NET - Part 3

In the introductory post we first looked at a simple turtle graphics engine for AutoCAD, which was followed up by this series looking at using it to generate fractals (here are parts 1 & 2). This post continues the organic fractal theme, by looking at another fractal found in nature, the humble fern. I found some simple Logo code in a presentation on the web: to fern :size if :size < 4 [stop] fd :size / 25 lt 90 fern :size * .3 rt 90 rt 90 fern :size * .3 lt 90 fern :size * .85 bk :size... Read more →

Turtle fractals in AutoCAD using .NET - Part 2

This series start with this initial post, where we looked at an implementation of a simple turtle graphics engine inside AutoCAD, and followed on with this previous post, where we refined the engine and looked at how we could use it to generate complex fractals with relatively little code. In this post we take a further look at fractal generation using the turtle graphic engine, with the particular focus on introducing randomness to generate more realistic, organic forms. On a side note, fractals and the use of randomness in design are two of my favourite topics, so this post... Read more →

Turtle fractals in AutoCAD using .NET - Part 1

This topic started in this recent post, where I introduced a simple turtle graphics engine for AutoCAD implemented in C#. My eventual aim is still to implement a subset of the Logo programming language in F#, calling through to this C# engine, but for now I've been side-tracked: I'm simply having too much fun with the engine itself and exploring the possibilities of turtle graphics inside AutoCAD - especially around the use of recursive algorithms to generate fractals. This post and the next (and maybe more, depending on how much fun I continue to have) will be devoted to... Read more →

Two years and counting...

Well, that came around quickly. Today is the 2nd anniversary of my first post to Through the Interface. I'll keep this one short and sweet, but expect something meatier in the next day or so. :-) Read more →

A simple turtle graphics implementation in AutoCAD using .NET

Like many thirty-something Brits (and possible non-Brits, for all I know) my earliest introduction to the world of graphics programming was via a language called Logo running on the BBC Microcomputer. This machine and its educational software were commonplace in UK schools in the 1980s, and I have clear memories of staying late at primary school (which I suppose means I was somewhere between 8 and 10) to fool around with BBC BASIC. With a friend I used to try to write text-based adventures ("you are in a cave, there are exits North, South, East and West" - you... Read more →

Cleaning up after yourself: how and when to dispose of AutoCAD objects in .NET

A question came up recently in an internal discussion and I thought I'd share it as it proved so illuminating. If I have an object of a type which implements IDisposable, is it good practice to explicitly dispose it (whether via the using statement or calling Dispose() explicitly)? The quick(ish) answer is: Yes it is, but sometimes you might choose not to as the increase in code simplicity outweighs the benefits derived from manually disposing of the objects. So, naturally, the devil is in the detail. Let's take a look at the three scenarios where you're likely to be... Read more →

AutoCAD .NET version of the ObjectARX BlockView sample

Fenton Webb, from DevTech Americas, has been beavering away on a .NET port of the ObjectARX BlockView sample (found on the ObjectARX SDK under samples/graphics/BlockView). Thanks, Fents! :-) Here is the C# source project for Visual Studio 2005. To build it you will almost certainly need to remap the acdbmgd.dll and acmgd.dll assembly references in the project. One important note: if you load this project and try to view the BlockViewDialog in the Visual Studio Designer, the Visual Studio application will almost certainly crash. This is because the Designer is attempting to load into the dialog the GsPreviewCtrl component... Read more →

A handy tool for migrating ObjectARX code to work with AutoCAD 2007 and beyond

Back in this previous post I mentioned a tool known as Teefy to help migrate C++ code to use Unicode for strings instead of MBCS. This tool was previously only made available to ADN members, but we now have a version that is available for everyone. And here it is. Read more →

DWF Toolkit 7.5 available

Over on Beyond the Paper, Volker Joseph has just announced the availability of the latest version of the DWF Toolkit, which - excitingly to me, at least - supports the XPS-compatible DWFx format. Read more →

DevTV on RealDWG

In addition to the existing collection of DevTV sessions, we have just posted a DevTV session on RealDWG. It is available for download (97.5 MB) or for online viewing. A big thanks to Adam Nagy from our DevTech team in Europe for delivering this informative session! Read more →

Zooming to a window or entity inside AutoCAD with .NET

This post was inspired by a recent email from Sreekar Devatha, who is just about to leave DevTech India to work in one of our Engineering teams in Singapore (all the best on your new adventure, Sreekar! :-). It shows how to perform a programmatic zoom in .NET, whether to a window or to an entity. The .NET API in AutoCAD doesn't expose a handy "ZoomWindow" method, but there are a few options open that use officially supported APIs: Create a ViewTableRecord and set it as the current view (the classic ObjectARX technique, as described in this DevNote on... Read more →

Looking for API developers to work with Project Draw

Over on It's Alive in the Lab, Scott Sheppard is looking for developers interested in working with the API to Project Draw. If you're interested, send an email. Read more →

Sectioning an AutoCAD solid using F#

In this earlier post we saw some C# code that creates 2D, 3D or "live" section geometry in AutoCAD 2007 or higher. I mentioned at the end of the post that I was curious to see how equivalent F# code compared with this C# source, especially in the area of array concatenation. Well, it turns out that there's still a little pain, just different pain (more like a sharp pain that's over quickly, rather than a dull, nagging ache :-). Here's the F# code: #light module SolidSection // Import managed assemblies #I @"C:\Program Files\Autodesk\AutoCAD 2009" #r "acdbmgd.dll" #r "acmgd.dll"... Read more →