V Carve Question

[vince mastrosimone]

I have a piece I want to make a V Carve file for. I traced the piece on paper with a pen, scanned it as a bitmap, imported it and converted to a vector. When I zoom in, there are two lines and when I double click on either black line I get two pink dashed vector lines. Why did I get two lines instead of one line on the bitmap import? I know dashed vector lines mean something and solid vector lines something else. How do I make the lines solid and what is the difference?<br><br>Thanks for help. Just plodding through the learning curve.

[David Buchhauser]

If you traced with a pen, then your tracing line width is probably so wide that both sides of the lines are being vectorized. You could probably delete one of the sets of vectors. I'm not sure why the lines are dashed and not solid pink, and a single click should turn the path from black to pink. Perhaps you could post some screenshots so we can see exactly what you have. Also post your bitmap file and I will take a look to see if I can clean it up for you.
David

[Jim Becker]

Dashed is a single vector. Solid is a grouped set of two or more vectors.

[vince mastrosimone]

Thanks for the offer David. I created a zip file with both the bmp and crv files. I hope you can help.

[Mark Bolton]

Bitmap trace will rarely if ever leave you with single line vectors. As David said, it will detect the thickness in the line and generate a vector on either side of the line (which is normal.. "the line" is actually its own entity)

Depending on the complexity of the drawing you may find that you have more post editing using bitmap trace than if you just loft lines around the sketch manually. On very complex traces it can save you a bit of time but even then you will more than likely still have a heavy amount of post processing/node editing after a bitmap trace. Where bitmap trace often shines is with thick line drawing that have well defined edges and very little noise in the source bitmap. Anything beyond that you will have a pretty hefty amount of cleanup.

Only you can decide if your faster getting some initial vectors from bitmap trace and then editing or just vectorizing the job from scratch. Perhaps not wise to weave another hefty variable into the process but you can often times come out ahead using a free program like Inkscape to generate clean vectors to then import into Vcarve for final tweak.

[vince mastrosimone]

Thanks Mark. I'll give Inkscape a try and see what I get.

[David Buchhauser]

Thanks Mark. I'll give Inkscape a try and see what I get.

Hi Mark,
I have downloaded your file and it does indeed have the usual problems from a hand trace. I will get back later today with a clean file and let you know how I edited it.
David

[Jim Becker]

MarK, thanks for the Inkscape recommendation. I plan on trying that out to see how well it will work for me, too.

[vince mastrosimone]

Thanks for doing that David

[David Buchhauser]

Hi Vince,
The bitmap from the scan of your hand tracing with pen would probably take many hours of node editing to clean up as a usable vector file. The easiest and quickest method to produce a usable vector file would be manual tracing in VCarve Pro. Here is how I would do it. It took me about 15 minutes to complete this process from start to finish.
David

Step 1 - Open your original bitmap file with Paint.net and invert colors. This will help with the visibility of the lines/curves while manually tracing.
Step 1 - Invert colors with Paint.net.jpg

The resulting file will look like this. I normally save from Paint.net in jpeg format.
Joseph - inverted colors.jpg

Step 2 - Import jpeg to Vcarve Pro.
Import jpeg to Vcarve Pro.jpg

Step 3 - Zoom in as shown, then use "Draw Curve" tool to manually trace around white path - trying to stay centered in the white path.
Step 3 - Trace path with Draw Curve tool.jpg Joseph tracing curve.jpg

Under Edit, Snap Options - I have my snaps set as shown. The main thing is that I want to snap to end of curve, and I don't want to snap to grid. I very seldom use this program, and I am sure there are probably other snap setting that the "experts" would recommend.
Snap Options.jpg

Here is the finished trace.
Joseph - finished trace.jpg

[vince mastrosimone]

David thank you for doing that for me. I appreciate your time and knowledge. It looks like the process is quite involved. I was hoping a quick scan would be all that is needed but alas that is not the case. I guess nothing worthwhile comes easy. It’s gonna take me some time to work through this. But thanks again for your help.

do you think turning down the resolution on the scan would help any?

[Mark Bolton]

do you think turning down the resolution on the scan would help any?

Other than a very bold, high contrast, sharp line reference image there is nothing thats going to give you a click and go option. You are likely just making it a bit more difficult than it actually is in your mind and hence shooting yourself in the foot. That image David processed for you is honestly about a 2-3 minute job straight in Vcarve using the draw curves and then a few seconds on node editing to smooth things up.

Now you get into things that are a bit more complex and there is more time in the curves/node editing but its really just wash rinse repeat when your working 2D-2.5D

Just give yourself some time and invest the time into figuring it out. Its not overly difficult.

[vince mastrosimone]

Thanks for the encouragement.

[David Buchhauser]

David thank you for doing that for me. I appreciate your time and knowledge. It looks like the process is quite involved. I was hoping a quick scan would be all that is needed but alas that is not the case. I guess nothing worthwhile comes easy. It’s gonna take me some time to work through this. But thanks again for your help.

do you think turning down the resolution on the scan would help any?

Hi Vince,
Turning down the resolution on the scan will not help. You never said what your end goal is with Joseph. Is this simply to learn how to convert bitmaps to vectors, or are you planning to engrave, route, or cut this shape on a cnc router, vinyl cutter, etc? There can be quite a difference between the result of a "quick & dirty" manual trace and that of a more detailed/accurate manual trace. It depends on how closely you want your final part to match the original. In any case, there are several techniques which you could employ to improve the quality of your bitmap image so that auto-tracing becomes practical.

Step 1 - Use a pen as you originally did to trace around your original onto a piece of dark colored paper.
Step 2 - With a sharp pair of scissors, cut along your traced line to produce a "template" of the original.
Step 3 - Scan your "template" to produce a bitmap file - as you originally did. If the "template" is too large to fit your scanner, place your "template" on top of a large white piece of paper (for contrasting background) and take a photo with your camera.
Step 4 - Import your bitmap file to VCarve Pro and auto-trace.
Step 5 - Edit as required.

I followed steps 1-3 above and here is the result of the scan.

Joseph black scan.jpg
Here it is imported to VCarve Pro.
Joseph black scan imported to VC pro.jpg

Trace bitmap.
Joseph black scan trace bitmap.jpg

Closed vector path after trace.
Joseph black scan closed vector path.jpg

Here are steps 1-3 but with the "template" photographed instead of scanned.

Photo of black template on white background.
20210102_174406_resized.jpg

I used Paint.net to crop photo.
Joseph photo 1.jpg

Import to VCarve Pro.
Joseph photo 1 imported to VC pro.jpg

Closed vector path after trace.
Joseph photo - trace bitmap result.jpg

When using "trace bitmap" for photos, it can be helpful to increase the noise filter setting from the default to around 8-10 pixels.

[David Buchhauser]

Vince - here are the resulting dxf files from the "trace bitmap" operations above.
David