Layering and vector cutting

[Bruce Clumpner]

Hey Folks!

I ran into a problem the other day when running a combined raster/vector job. I'm running Corel x4 and an epilog mini 35watt with updated print driver and firmware. I have also been using Corel now for many years.

Here's what happened. I had a shape I was going to both raster mark and cut-out and then overlayed it with another element that had no vector cutting. I had assumed that any vector line placed behind another element would only cut along the exposed lines, leaving the covered portions alone. Unfortunately that was not the case and it cut along all of the vector lines, even if hidden, and ruined the piece.

Now I can start breaking up my art so that this would work properly, but that just adds time to the job. Is this the way the print driver sees the vector objects and is there an easy way to get around it?

thanks.

bc

[Joe Pelonio]

Unlike bitmaps for engraving that can be covered up, vectors always run. You can use color mapping to set the speed to 100 and the power to 0 though, and it will quickly go through the motion without actually cutting into it. That is, if I understand the question correctly.

[Mike Null]

Bruce

It sounds like you may not have turned off the vector layer before sending it to the laser.

[Rodne Gold]

You will have to use the virtual segment delete tool and use your overlapping graphic as the boundaries for trimming the vector that lies underneath it.

[Bill Jermyn]

Here's how I do it.
http://www.youtube.com/watch?v=V4uo_nRB4Ho

[Lee DeRaud]

Unlike bitmaps for engraving that can be covered up, vectors always run.

I would consider that a "bug" (or maybe "BUG!!") except that it appears to be universal across all laser/driver vendors and versions.

Any clue how it became the standard? Or is it really that hard to program hidden-line-removal into the driver?

[Bruce Clumpner]

Your video tutorial provides me a short-cut to the process. I guess I'll have to keep this "feature" in mind for future jobs.

Thanks everyone for their input.

Bruce

[Richard Rumancik]

I would consider that a "bug" (or maybe "BUG!!") except that it appears to be universal across all laser/driver vendors and versions.

Any clue how it became the standard? Or is it really that hard to program hidden-line-removal into the driver?

I suppose raster works that way because it is likely a simple algorithm to overlay two bitmaps, and then do a binary comparison of the layers. If the front-layer "dot" is white, then it overrides any black dots underneath, and will not print/laser that dot.

But to do that with a vector shape, it would need to determine the coordinates of the the "intersections" between the vector and the bitmap, and try to clip out parts of the vector that shouldn't be there. This would probably not be that trivial. Perhaps even impossible with complex images.

A lot of CorelDraw clipart has this problem. If you look at the colored image it looks fine, but it is probably comprised of a lot of overlapping filled shapes. It can take a lot of work to prepare such a vector image for lasering.

[Mike Null]

It seems to me that Universal had an option in my first machine called clipart mode which would solve this problem. It's been a while and I'm a little vague on it. Maybe Mike Mckenzie can weigh in.

[Lee DeRaud]

It seems to me that Universal had an option in my first machine called clipart mode which would solve this problem.

That option still exists...I'll have to try it. My recollection from the docs made it sound like it was for something else though.

It's been a while and I'm a little vague on it.

There's a lot of that going around.