Hey guys! I’m a new Rhino user and need some help. My background is Inventor and Solidworks, but that was ages ago and I switched to Rhino as it’s more mesh friendly.
Part of my small business involves taking 3D scan meshes and converting them into molds (for composites). While I’ve gotten good at creating molds using ribbon offset, dupboarder and other sequences, I’m struggling a lot with getting the scan ready to make the mold. The primary issue I’m having is with the scanned edges. They are very jagged and I need a smooth line before I can begin building a mold from it. I’ve tried using dupboarder and smoothing that but I’m not really sure where to go.. Manually adjusting every point on the mold takes a ton of time and isn’t really feasible for me to do.
How can I do this a little bit easier. Are there grasshopper automations that I can use? I’m not that familiar with grasshopper, but it seems pretty useful once you get it set up.
Ideally you woudl smoothen these edges in the scanner post processing software.
There is also a Smooth command in Rhino and one way to deal with such edges is to redraw a polyline or interpolated curve and pull naked vertices to that nice curve.
I’m not sure how that would be possible with the scanning software. While there are plenty of smoothing tools, there’s nothing that is for the edge.
I used dubboarder and ran a smooth command on it. Not sure how to connect that line to the jagged edge above, However. Loft didn’t seem to work. Are there other commands I should try using to make the polyline or connect the line to the part?
Its possible your end use does not require full reverse engineering of the scan to a nurbs model.
However, you can only go so far with working with the limitations of meshes, and it sounds like you may be hitting that limit.
“Manually adjusting every point on the mold takes a ton of time and isn’t really feasible for me to do.”
If you build the model by manually creating curves and surfaces with as few points as possible to create the shape, you will have more precise control in editing, rather than pulling mesh points around.
Typically you would create surfaces that extend beyond the edges of your reference mesh, and then use intersection / trimming to get clean edges in the nurbs model, so you are not using the mesh directly to generate the edges.
You might search for reverse engineering here on the forum, there are many good threads that describe the process.
Alright, So probably need to clarify, I’m only scanning and trying to capture the top scan of this item. I’m not trying to get a complete 3D scan. that top scan is used to make an open mold. i.e. an impression into a surface (think 1/2 of an enclosed mold). Then I extrude the surface to a flat plane to make the mold.
I’ve rescanned the part to recapture the tape flange that I use while scanning. I typically remove this using the scanning software and then just import the part into Rhino (as seen in the file I posted before). Let me know if this works better. You would need to remove the tape flange in Rhino, but it might make the edge easier to create?
Meshmixer (free) uses a paint brush tool that can filter triangles in a selection based on crease angle. It should give you a more precise result based on the last mesh you posted that includes the tape, and you should be able to eliminate the tape relatively cleanly from the form.
