Creating a solid surface from a hand drawing/Question

Hi all, first time on the forum here. I am a public artist and steel fabricator. I end up doing a lot of hand drawings and then cutting the images out of steel. I have been using sketch up pro for a couple years now. I would say I am competent but not proficient. I have a regular need to take my hand drawings and turn them into a solid surface on Skp so that I can model for clients and study shadows, etc.

Currently I draw by hand, trace drawing on GIMP, copy/paste to INKSCAPE (trace bitmap to create a vector file), export as a PNG, then convert the PNG to a DXF on CONVERTIO.

At that point I usually click and drag or import the DXF file to Skp where it shows up as a component (I think). Then I “heal” the surface by drawing a line through it, then I select the surface and all the image lines and “intersect faces > with selection” and “weld edges”
At this point the pinwheel starts spinning and often throws skp into non-response and I sometimes have to force quit or wait a very long time. Obviously more so when the images are more detailed.

When it does work I can then delete the negative space in the image and push/pull the image into an dimensional material and it is great!

Question: is there a better way to do what I am trying to do?
Is there a reason that the “intersect faces” and/or “weld lines” overwhelms everything?

Any advice would be appreciated.

FYI-I have a 2015 macbook pro quadcore intel i7 and a 2020 M1 mac mini. Similar results on both but seems like sometimes the macbook actually does better with this procedure. Both have 16gb

Without seeing one of your dxf or skp files, the result of converting your raster line art to dxf results in a huge number of edge segments that SketchUp has to look at for welding or intersecting. Might be easier to import your raster image directly into SketchUp and then trace over it with the varioous drawing tools. It would almost certainly reduce the number of edges segments.

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As DaveR mentioned, it might be best to just import your hand drawing in as an image and either use it as a tracing element or just to use it as a visual reference to develop the 3D model.

In order to validate and refine our recommendations, can you upload an example of your hand drawings? We may be able to help a bit more if we were to see what type of work you are creating.


Thank you! Yeah, I have attempted to do the tracing before but here is an example.

Needless to say it would be incredibly time consuming.

My Plasma cutting software (Enroute) has a “simplify” function that reduces the segments or nodes on the file. Didnt know if there was something like that that can be done to a DXF file in skp or to the file before its imported.

So admittedly that is a complex thing to draw. You might use Curvizard from Fredo6 to simplify the imported CAD linework but no matter what, I would expect it to take some time.

What is your finished product like? A grille?

I am a bit puzzled: Do you really need to do a bitmap to vector conversion twice? Can’t you export a DXF directly from Inkscape?

Here’s how I would do it…similar to what your described but using Adobe Illustrator rather than Inkscape.

In Illustrator, use the ‘Image Trace’ function to convert the PNG to Vector lines:

Then export as DWG. Import into SketchUp and you’re golden. If you need the linework to be filled with faces, I recommend Eneroth’s brilliant ‘FaceCreator’ extension:

Here it is extruded as you can see.

And the DWG if you need it - though I recommend learning this process if you do this a lot. Adobe Creative Suite does bill monthly so you could just purchase it as needed if it’s not something use daily :wink:
Chandler final image black.dwg (827.5 KB)