Trace bitmap as single lines to profile?

[llwood]

I have attached an image of a spider web. It's easy to trace the bitmap to create a set of closed polygons that can be easily vcarved or pocketed. But in some cases it would work better to have single lines to profile rather than polygons. Is there any way to either:
1. Have the trace bitmap routine create lines rather than polygons, or:
2. Create single lines between the polygons, or convert the polygons to single lines that can be profiled to create a similar effect.

For example, in the attached picture of the spider web, I would like to cut with a 1/8" end mill along the center of each of the web segments to cut the web. Profiling on the polygons created by the trace bitmap routine cuts too much.

I need to import this bitmap and trim vectors before cutting. This is why profiling on the inside or outside doesn't work, because there are some closed vectors and some open vectors. It's also why pocketing or vcarving don't work.

Is there any way better than drawing the curves by hand? Any suggestions would be appreciated.

Thanks,
--Andy

[llwood]

Here are a couple previews of the actual project that I'm trying to get done before Halloween. The .crv file is too big to upload, so I'm uploading previews instead.

Thanks,
--Andy

[dhellew2]

Is this what you had in mind?

Used trace tool and a v-bit

Or this, draw one then use circular array

Dale

[ssflyer]

Minor comment - don't spiders have only two body segments?

[Mike-S]

Yeah, and the web is a spiral. The Halloween police are gunna getcha.

[dhellew2]

Another option, this is how I would create a typical Halloween symmetrical spider web (real spider webs come in many different shapes).

View one: Draw a vector from the center outwards, use radial array to create 11 vectors, draw 3-point arcs between two vectors, delete remaining 9 vectors, select all then using radial array create 11 items

View two: ends of webs snapped to the same points; Draw a vector from the center outwards, use radial array to create 22 vectors, using snaps draw a vector at the end of the 1st and 3rd vectors, offset the vector towards the center the desired distance, using snaps draw 3-point arcs at the intersection of the 1st vector, center vector, and 3rd vector for each offset vector, clip and/and or delete all unused vectors, use edit then select all duplicate vectors and delete them, select all then use radial array to create 11 items (View three).

Dale

[Boltz]

In answer to the original question, the only way I know of to get a good single line trace is Adobe Illustrator and a skilled operator.

[Adrian]

There a few packages out there that will do centre line tracing automatically. I occasionally use one called Magic Tracer made by Elgorithms but there are others some of which are free.

99% of the time I trace by hand as it gives much better results and is often faster than cleaning up an automatic image trace.

[llwood]

Minor comment - don't spiders have only two body segments?

LOL! I guess I'm showing my ignorance not only of spiders but of webs. Well, in any case, I'm may have to take some poetic license and use 3 body segments because it works out better that way. I originally had a large body segment for the abdomen, and medium-sized one for the thorax and a small one for the head, but I couldn't get the segments to go together in a way that worked. I tried having some distance between them or having them at different depths, but nothing looked right, so I did all segments the same size.

Well, if spiders have 2 body segments, I tried putting the eyes on the segment with the legs and deleting the head. What do you think of this?

--Andy

[llwood]

Thanks for all the suggestions about doing centerline tracing or creating a symmetrical spider web. The original .crv file I posted may have been misleading because I do want to create an asymmetrical spider web, as shown in this file.

One thought I had was to offset all the vectors in the web to that every set of 2 adjacent lines would roughly overlap each other. This creates an appearance that's better, but it's horribly inefficient. I started to delete segments to avoid the repetition but in so doing I realized it would be easier just to trace the thing by hand. So based on the suggestions I got here, I will do that instead.

I wasted a huge amount of time trying to save time!

Thanks,
--Andy

[llwood]

Any of us who contributed to this post could now get a job in web design.

[llwood]

As a result of all the comments and advice here, I redid both the spider and the web. Happy Halloween!!

[PaulRowntree]

Looks good Andy! But why again wouldn't V-carving work for you? If the spider is the issue, he could be separately cut and placed on the web as a physical piece.

[llwood]

Looks good Andy! But why again wouldn't V-carving work for you? If the spider is the issue, he could be separately cut and placed on the web as a physical piece.

Paul, the spider was the issue. I didn't want the vbit to cut into the spider. True, it could be cut separately, but I was afraid that since the legs are pretty long and thin, that they might have a tendency to break off if cut separately. Cutting it all as one piece eliminates this weakness.

[llwood]

Thanks for all the input I got here. We got this cut in time for Halloween and I put some pictures on the gallery here:
http://forum.vectric.com/viewtopic.php? ... 57#p148257

Thanks,
--Andy