corel draw

[GWS.Arkansas]

Ok i have corel draw x3 and i have seen x5 advertised. and also i have seen x12 and so on which one is the best for me? Is it the higher the number the better or what ? can someone help??

[SignTorch Vector Art]

The later versions are better, the X is roman numeral ten, so X3 is version thirteen, and so on...

X5 has two advantages over X3 (and X4 I think)

1) it has a join curves tool which is handy

2) it can export older dxf versions without splines (which was removed in X3)

based on assuming you have X3 and command-n-cut and can export and use PLT format instead of DXF, I don't see any reason to upgrade, unless you just want X5's join curve tool, or unless you need older DXF export for some reason

You surely don't want to downgrade below X3

and I'm betting that X6 will come out in 2012

[Dawgonhawg]

Gary I have Corel x5 ordered and can't wait for it to get here. I will have lost of questions I'm sure of that...lol.
First questions. Can you explain what is a "spline? Your help will be appericated.
Thanks,Dawg.

[SignTorch Vector Art]

A spline is the CAD equivalent of what's called a bezier curve in desktop graphics apps.

Historically DXF for machining was a lot like g-code, it only had arc and line geometry.

The only thing unlike g-code back then was smoothed polylines.

DXF was always a good simple format to convey standard geometry for cnc purposes.

Since then, desktop vector graphics became popular, with EPS and AI formats which use bezier curves.

Because bezier curves can represent natural smooth flowing curves better than standard geometry. In nature there are no true arcs or straight lines, so beziers just work better for artistic applications.

Since after version 14 autocad DXF incorporated bezier curves and calls them splines.

Arcs and lines have definite end and center points and radii which are easy to calculate to high precision and can transfer directly to gcode.

Bezier curves (and splines) however are defined by two endpoints and one or two control points, and the mathematics are a lot more complicated. A single bezier curve can form a range of shapes from a straight line, or a loop, to double curves that change turn direction.

The real problem with beziers is that the mathematics are just an approximation, and very complicated and unpredictable, and they can't even form a true radial arc. That is why there is no gcode equivalent to spline geometry. The only way to plot them is to calculate a whole bunch of points along the curve and you'd have to plot an infinite number of points to achieve the same high level of mathematical precision as an arc.

It's easy to plot a spline on a computer screen that doesn't move, and it looks simple, but it's really difficult to get a machine to move at a constant rate along a spline without some potential for errors, and it's equally difficult to convert bezier curves into standard geometry without errors.

Part of the problem is how computers and internet and cnc technology have evolved so rapidly in recent years. Anyone can build and market cnc machines and software these days without much expertise at all, it kills me, even many vendors don't know the difference between standard geometry and bezier curves. No wonder it is so confusing.

Vinyl cutters work with bezier curves, I suspect eventually all cnc will, but for now gcode is the standard for cnc and it is simply not directly compatible with the bezier curves used in desktop vector art.

[Dawgonhawg]

Gar, thank you very much for the detailed explanation of a spline.
Dawg

[Dawgonhawg]

Sorry for the typo. Thank you Gary.
Dawg