Q&A

VersaCAD

I'm not sure we could implement prior to the launch at the end of March. We are still a Carbon app so I'm not sure how much work this will be for us but I'll take a look at the code and see if this is something that would be feasible for us to implement.

Mike Lazear
Archway Systems

Intaglio

Intaglio is strictly 2D drawing and we don't currently support DWG. However if we move in that direction I'll keep OpenClip in mind.

Nick Nallick
Purgatory Design

Thanks, but you have misunderstood what OpenClip is. It has nothing to do with DWG. It provides a way to copy and paste between any illustration, drawing or CAD programs, 2D to 2D, 2D to 3D, or 3D to 3D. And in particular, it provides a way to avoid supporting DWG, which is something perhaps everyone should do! So you could copy from 2D Intaglio to 2D PowerCADD with OpenClip.—Alfred Scott

EazyDraw

This should not be a problem. I just did svg export and import and DXF import. So this is just for Mac only - pList are unique to Mac are they not?

I'll need to study you website some more. I'm finalizing EazyDraw 3.4 this week so it will not make this release. I'll start working into the next public beta after this release.

When do you plan to go public?

Dave Mattson
Dekorra Optics LLC

OpenClip puts its data into a NSDictionary as a property list, but the files are saved as generic xml, which can be cross-platform. We will be working on how to do this with Windows and do not think it's a big deal.

Plan to go public around the end of March.—Alfred Scott

RealCADD

I think that OpenClip is a good idea.

I will see what I can do with it and RealCADD, but because RealCADD is written with REALbasic, I can't deal directly with NSDictionary. Perhaps with the MBS plugins or with the next Cocoa version of REALbasic.

Eric POUSSE
RealCADD

TouchCAD

Thanks for the information. I will have a look at it.

A spontaneous question is: Does it work the other way around?

In my experience, most TouchCAD pro users model from scratch in 3D and then use an external program for drafting and documentation, and of course very often directly to the cutting machine. The reason for this is that TouchCAD is highly specialized on very precise free form 3D shaping, where the 3D feedback is essential.

I can however understand your approach for architectural modeling, which usually is based on plan views and simple shapes.

Though all TouchCAD development takes place on Macs, it is still a cross platform product. So, any plans for the Window side?

Claes Lundstrom
Lundstrom Design

The best first step is to implement Paste. This will make it easy for you to understand the concepts.

Of course it works the other way, but your program has to implement Copy to OpenClip for another program to Paste. It will be up to you on what you put back in the way of 2D drawing line work. You could put an entire three-view with a perspective view if you like, or you could do just basic lines. It really depends on what your users need and want.

We will be working on getting OpenClip working with Windows. We don't think it's a difficult thing at all.—Alfred Scott

MacDraft and Microspot Interiors

We have two main families of CAD products, MacDraft for 2D drafting and Microspot Interiors (used to be called 3D World) which is a 3D design and rendering application with a fairly large library of ready made items for inside buildings. Rendering varies from interactive (not per pixel shading) up to ray tracing with shadows, reflections and of course per pixel shading.

The current development versions of both these application families support pixel maps with alpha channels. We support PDF export from both programs and still use Apple's abandoned QuickDraw3D format for our 3D data files, now via the Quesa open source project which we contribute code to.

From the little I have read so far I think the EXPORT of OpenClip from MacDraft might be fairly easy, though it is a Carbon application, now nearly 25 years old and still going strong, though it has gone through many changes like being recoded from Pascal/Assembler into C++, QuickDraw to Quartz, 68k to PPC to Intel, big endian to little endian etc. I think we could clone and then modify the existing Quartz/PDF drawing routines to export OpenClip instead. We would have to throw away any raster data unfortunately unless OpenClip could be expanded to incorporate it.

It doesn't matter that MacDraft is a Carbon application. OpenClip works equally well in Carbon and Cocoa apps.

Your EXPORT is what I'm calling a Copy operation in OpenClip. Typically you select objects, select Copy and then move to another program to Paste. For this, it makes sense to put 2D objects into the drawing, and as MacDraft is a 2D drafting program, you would be essentially doing the same thing that I do from 2D PowerCADD with the PowerCADD/WildTools OpenClip plug-in. However, I assume your program has graphic primitives such as lines, rectangles, polygons, etc. Typically you would run through the drawing for selected drawing objects and put them on the pasteboard using OpenClip.

As far as IMPORT into MacDraft is concerned I have been wanting to do PDF import for some time but not had the manpower available. Do you think that OpenClip would be easier? If so, any idea how much easier?

Oh my lord! Parsing a PDF is a monumental task. I've heard it said that the PDF specification is 25000 pages. And even when you parse it, you don't necessarily have useful data. Everything comes in as bezier paths, so there's no identification of what is a line, rectangle, circle... and arrows on ends of object are more paths. Be careful what you ask for!

You can think of OpenClip as 'PDF for the rest of us—or at least us CADs." Your IMPORT is what I'm calling a Paste operation in OpenClip. Typically this is the first thing you will do and as you will see, it's very easy. Tim Hanes did it for Bonzai3D in 12 hours.

Our 3D applications are considerably younger and I and my team converted them to Cocoa a while ago. As far as EXPORT is concerned, I get the feeling OpenClip is not quite suitable for us. We need to embed lights, pixel maps with UV mapping for all coordinate points. To throw these away would reduce the file size by about 90%. I do not think anyone would want to use the lifeless resulting models.

You are exactly right about this. OpenClip is not suitable for all of the shading, 3D effects and views. It is an appropriate tool to produce 2D drawings from 3D models and objects. It's really a question of how you want to go from a 3D model to 2D drawings.

However, IMPORT into our 3D products sounds much more useful. There are two ways of doing it. We could write an import plugin for our application. Are you in contact with any of the other Quesa people? Quesa does support import from other formats. You might like to send an e-mail to Quesa Develop <quesa-develop@lists.sourceforge.net>. I would not want to leak this to anyone you have not already chosen to contact so I will not contact them without your permission but I would like their view if such a facility would be viable and worthwhile. That way OpenClip might get multiple applications importing with just one development project.

Yes again. You want to be able to take 2D drawings and paste them into your 3D program. This is the easiest and typically the first thing you would do. My suggestion is that you first do the OpenClip Paste to MacDraft, the OpenClip Paste to your 3D programs, then work on Copy last after you see how it all works.

Please go ahead and forward this to the Quesa mail list, and just ask them to use their discretion. I'm not going to get angry at anyone about this. It's just that I would like to have a big splash when it all is public. Certainly, it will be better for your programs if it all gets announced at one time.—Alfred Scott

Roger Holmes
Technical Director
Microspot Ltd.

MacDraft and Microspot Interiors

I have just read through the email you sent to us regarding the OpenClip method for copy and paste in CAD programs. I have to say I am very intrigued by this method and would love to know some more about it. I completely agree that the concept of DWG and DXF compatibility is never a perfect science. I have a few question if you would not mind giving me some information?

1. As MacDraft Professional already supports DWG and DXF files, would there be any conflicts between them and OpenClip, or would it simply be another export (copy & paste) feature?

No conflict at all. Just an additional feature to the programs.

2. I have had a read through the website and was excited to see the 2D vector art copied and pasted into a 3D application. How exactly is this handled (is the 2D vector art turned into 3D surface geometries), as we would love to be able to copy our 2D plans into our 3D interior design application?

That is up to how the OpenClip paste is handled in your 3D application. It is essentially identical in process to importing 2D line work with DWG and DXF.

If you are talking about the frog, this is something Matt Arnold created using the SketchTools palette of WildTools for a Civil war book. In SketchTools, you can use a pressure-sensitive tablet. The pen strokes are actually polygons filled with a black color and with no pen stroke around the polygons.

3. I would be keen to know what level of development (timeframe) would be needed to implement this feature into our software?

OpenClip Paste is the logical first step. Tim Hanes did it for Bonzai3D in 12 hours (which for a feature like this, is almost nothing).

The OpenClip Copy operations would be the logical next step. For MacDraft, this would be a very simple thing, perhaps another two days of work. A Copy operation from a 3D application will require you to spend time thinking of what you really want to copy for a 2D application or perhaps another 3D application. While this programming for OpenClip is still very simple, this will require more think-time in the design phase. In WildTools, I ended up with four specialized Copy methods. One is a 3D copy capability and three are in TopoTools for copying 3D surfaces and topo contours.

4. Although the website gives a lot of information about what the OpenClip is and does, and I appreciate that it is under development, but I was unable to get an idea of what exactly is needed on our part. Is it simply an SDK pack that will be provided, or is it a stream of source code that will need to be implemented into the code?

No SDK or specialized library. All that is required is shown in the example programming. You don't want to make it into anything more complicated than it is. Your programmers will not have any difficulty with this. As with anything, the hardest part is getting started.

Phil Bunker
Design and Marketing Coordinator

In thinking about it overnight, it dawned on me that apparently you cannot copy and paste vector graphics between MacDraft and Microspot Interiors and that OpenClip would allow you to implement that.

Ordinarily with translators, you have to exactly match the data structures bit-for-bit or something blows up on you. With this approach, you don't have to do that, and it also gives you the freedom to do some things that might not have occurred to you yet.

The OpenClip tags for the key-value-pair dictionary are simply things that we invented to handle the most common objects that would exist in a CAD or illustration program, and also those that would closely parallel the Quartz/PDF model. We expect to add more, particularly to handle 3D solid objects and nurbs.

But you also have the ability to add your own tags. With data stored in this way, for all anyone cares, you can put your grandmother's maiden name in the OpenClip file with your own tag. It would not hurt a thing and would cause no problems. It would only create a problem if you started using a tag that we all started using ourselves for something else, and even then, probably nothing would blow up if you write your programming right.

It's a good idea to go very slow with this sort of thing until you are completely familiar and comfortable with the NSDictionary concept, but my point is that you can add 'fields of data' (effectively) for your use between your two programs.—Alfred Scott