Hi Michael,
For V3, Can you please put a "print function" like Rhino for architect to do plan, and perspective etc...
I choose MoI because it's better for me than skechup. I use ArchiCAD over 20 years but it can't do things simple
Thanks
Tyéri

Hi Tyéri, there's a feature request thread over here for v3:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3628.1

What I think will probably happen for v3 is that I'll try to make a 2D hidden line export mechanism for generating 2D AI or DXF files, then you would be able to take those files into a variety of 2D CAD or illustration programs (there are many free or very inexpensive programs of that type) and then print from there.

Eventually I do want to include printing built directly into MoI, but that is probably not likely for v3.

- Michael

You didnt mention pdf, i'd prefer that personally.

Hi Ed, PDF for 2D output is on my radar - it seems that there are some kinds of CNC cutter apps that primarily want DXF though so that may come first.

The main 2D formats that are on my radar right now are AI, DXF, PDF, and SVG.

- Michael

Great!

Hi Michael,

If you do pursue a 2d dxf export, having a user definable tolerance would be very useful to convert splines to arcs.
Ideally you would be able to do conversion within Moi so see the results, but just having a tolerance on the export would be OK as you could check it in another application.

The reason a lot of CNC apps still want DXF format is specifically for arcs. Splines are not typically supported in CNC applications, and when they are, there still can be some question about how they get converted to arcs. Because there is no standardized method for converting a spline or bezier curve to a series of arcs, the only guarantee you will get a specific output is to start with arcs.

I have seen some really scary results from using splines, and granted, it was on a CADCAM system from the early 90s, but a lot of those systems are still around.

Chris

Hi Chris, a spline-to-arc conversion for DXF output is something that I would like to add but that probably won't come in the first round of work on this area. I'm not quite sure how much work it involves to make a good quality conversion, I think it's kind of easy for that kind of converter to produce arcs that sort of wobble back and forth quite a bit.

I'm pretty sure that Rhino has a good method for doing a conversion to arcs, so right now if you need that kind of conversion of splines to arcs using Rhino is probably your best bet.

- Michael

Good quality conversion for CADCAM requires tangental arcs, or as close to tangental as possible within a specified tolerance value.

I would rather wait for a better quality conversion myself, and there are commercial products selling for hundreds of dollars (even more than the selling price of Moi!) that do a good job.

Since you mentioned CNC cutting apps, its my opinion that if you want to support DXF for that purpose, you have to include tangental arcs in the output.

Chris

Hi Chris, there seems to be a category of I guess maybe vinyl cutting type machines that have some software that seems to work ok with full splines in DXF format.

Some people have found that conversion utility helped them get curves into their cutting software even though it only converts full splines and does not do conversion to arcs.

Maybe in those cases the bundled software for the machine is doing arc conversion itself or something like that.

But at any rate I do know that export to DXF with full splines without arc conversion has helped some people for particular CNC work before.

I don't doubt that for other purposes arc conversion would be required - there is a lot of variation between different types of CNC use and different kinds of receiving software.

- Michael

Hi Michael,

Yes, it would depend on what you are doing with the file for any conversion issues to become significant.

Most modern vinyl cutting software accepts splines or bezier curves. These are converted into HPGL instructions to send to a vinyl cutter. HPGL has no native support for spline or bezier curves, and relies on the "host" software to do the conversion. Generally speaking, there is less of an opportunity for spline conversion issues to have an impact on output with vinyl cutters than with CNC routers. Vinyl cutters have little to no offset applied to the toolpath. CNC routers, on the other hand, may have a large offset (the radius of the cutting tool). Any problems with spline conversion may be compounded by the size of the cutting tool that is used.

Also, since parts cut by a vinyl cutter do not have a visible edge, vinyl is forgiving of all but the most obvious errors. However, parts with a thickness can be sensitive to a poor spline conversion, and, without some human intervention prior to actually cutting the part, can produce results comparable to a hacksaw.

Chris