Reverse Engineering Workflow

[Lucas]

My company just got a Faro arm and I will handle the Reverse Engineering to go to our LPBF printer. I do have experience handling STL data in Materialise Magics and some topology fundamentals in Blender (clean up and manual edition), but never worked with scans and RE.
So I am looking for workflow techniques to make the bridge from STL to NURBS; or maybe go straight with STL data to SolidWorks(?).

- Do you have any recommendations? Links, studies, pdf, videos etc
- Cheap SolidWorks Add-Ins?
- How do you do RE? What's your workflow? (especially using SolidWorks)

The software that I have available for editing the scans are: Materialise Magics, Blender and PolyWorks Inspector Premium (comes with Modeler Light - that can edit the mesh a little better than Magics)... unfortunately Geomagic Design X or PolyWorks Modeler are out of question (USD 20,000 lol)



What I did so far:

Recently I have been using the Rhino7 trial and testing some SubD and Lattice in Grasshopper; there’s QuadRemesh that converts Mesh to SubD and later it’s possible to convert it to NURBS (plus Rebuild the surface etc). Anyone using Rhino for RE? For what I checked it’s cheaper than most SW RE Add-Ins…

Sharing the results from today. I got the this scan from last week Faro’s training:

After cleaning up the noises and trimming the borders I used Magics' ShrinkWrap to patch and reduce the polygons:

Then I imported it to Rhino, used QuadRemesh and (convert)ToNurbs. Ended up with 110 NURBS surfaces, (which would be better to Rebuild to reduce the amount):
*STL, SubD and NURBS

The final result in Magics again:

Some Booleans, because why not? lol

What do you think? Is Rhino worth buying for it?
We did not scan any machine parts during the training, still my main worry is working in SolidWorks. I will try to find some pieces to scan this week.

[zxys001]

What do you think? Is Rhino worth buying for it?
We did not scan any machine parts during the training, still my main worry is working in SolidWorks. I will try to find some pieces to scan this week.

Yes, it's worth it. Rhino3D is one of the best overall 3D utility tools I have ever owned.

Also.. the other alternative is Power Surfacing or Power Surfacing RE for SolidWorks.

[Lucas]

Yes, it's worth it. Rhino3D is one of the best overall 3D utility tools I have every owned.

Also.. the other alternative is Power Surfacing or Power Surfacing RE for SolidWorks.

Thanks for the reply, @zxys001. We might end up getting Rhino for what I talked to my boss, the price is pretty small compared to everything that is available and looks like it can handle well converting STL to STEP for SolidWorks, not to mention everything else that is included.

May I ask how you do your RE process?

[jayar]

There once was an add-in for SWX from Faro Arm, maybe 15 years ago? Looked like a fast and easy way to RE. IDK if anything like it is still available.

[Lucas]

There once was an add-in for SWX from Faro Arm, maybe 15 years ago? Looked like a fast and easy way to RE. IDK if anything like it is still available.

Yep, you are right. Faro Edge and Focus 3D, but looks like they discontinued it.

They have now the RevEng software, which did not come installed in the laptop included with the Faro arm we bought, and might be sold separately.
I requested a trial key on Monday, but they did not answer yet; today is a holiday here

[Austin Schukar]

We have Geomagic Design X/Polyworks/SW; however, we just finished our trials of Geomagic's SW add-in, Geomagic for SolidWorks (GM4SW). I have to say, it's pretty good at first glance, but still a bit pricey. Think we came in around $8k or something like that, but not positive.

With GM4SW, my workflow can now be:

1. Import STL into SW via GM4SW
2. Clean up mesh
3. Get planes/cross sections/regions/primitives via add-in
4. Surface from references noted in [3]

We're still working our processes out, and are finding it difficult to use SW for some of these surfacing needed when reverse engineering...for some unknown reason, we have ruled out Rhino, but I would love to give it a spin.

[Lucas]

We have Geomagic Design X/Polyworks/SW; however, we just finished our trials of Geomagic's SW add-in, Geomagic for SolidWorks (GM4SW). I have to say, it's pretty good at first glance, but still a bit pricey. Think we came in around $8k or something like that, but not positive.

With GM4SW, my workflow can now be:

1. Import STL into SW via GM4SW
2. Clean up mesh
3. Get planes/cross sections/regions/primitives via add-in
4. Surface from references noted in [3]

We're still working our processes out, and are finding it difficult to use SW for some of these surfacing needed when reverse engineering...for some unknown reason, we have ruled out Rhino, but I would love to give it a spin.

You think the Add-in is better than the software? Does it jams when importing high detailed mesh?
Did not have the opportunity to test them, the add-in is still pretty expensive :/

[Austin Schukar]

You think the Add-in is better than the software? Does it jams when importing high detailed mesh?
Did not have the opportunity to test them, the add-in is still pretty expensive :/

I would say that the add-in is not even close to the software. It's still a big quality-of-life improvement for our group because we only have one geomagic DX dongle license. So we get the meshes we need, while our DX guy can focus on heavier reverse engineering and mesh editing with the regular software.

I agree on price. We pay WAY too much for software.

Edit: it does jam on large meshes, but those are pretty big. Like whole decimated aircraft big. I can import those meshes, just can't edit it

[Arthur NY]

Lucas: you may have already worked through this but if not, I've been 3D Scanning for about 20 years now, and there are SO many different ways to skin this cat.

I think as you have seen it's really ALL about getting the best scanned data from the beginning. This definitely saves SO much time in terms of having to clean up the data in post. One of the things to understand is that there are difference between converting data and reverse engineering and each of these 3D software packages can handle these two sides of the equation very differently. One aspect that it sounds like you've experienced is decimating a mesh. There is generally a loss in details when this happens and in some instances you have to play around polygon count or % of reduction.

In terms of additional softwware to add to the pipeline, since it sounds like you have Solidworks I can tell you that the Power Surfacing plug-in will be the better route to go. Not that using Rhino3D is bad but in terms of conversion and working through this process there are some amazing tools that are a bit more optimized. And I use Rhino3D all the time so it's not a bad choice but if I have to choose between these two then I go with Power Surfacing.

I'll also say this about software pricing. Yes the price tag of some of these packages "might" be a lot to pay upfront, but I also know that the difference in functionality is something that has to be taken into consideration. If software "X" takes 50% of the time to something that software "Y" takes twice as long then that extra time equates to $$$ which, and this is a BIG "if", a company has it's metrics dialed in then the ROI can be calculated over the course of 3 -5 years. The company a Faro Arm for a reason and the software to handle the data may need to match it.

[Lucas]

I think as you have seen it's really ALL about getting the best scanned data from the beginning. This definitely saves SO much time in terms of having to clean up the data in post. One of the things to understand is that there are difference between converting data and reverse engineering and each of these 3D software packages can handle these two sides of the equation very differently. One aspect that it sounds like you've experienced is decimating a mesh. There is generally a loss in details when this happens and in some instances you have to play around polygon count or % of reduction.

Indeed, in the beginning I was scanning without spray and was almost impossible to get the the small details on the mesh. Which was leading me to conclude that it would be much better to work with photos instead. lol

It's not decided what software we are going to buy yet. I was checking Rhino due to the design freedom for 3D Printing and ended up being the cheapest solution available to convert Mesh to NURBS. The problem is the huge workaround to avoid a RE software. Starts with PolyWorks Inspector and Modeler, Materialise Magics for Wrap and decimate, Rhino to convert to NURBS and some SubD adjustment. Blender could also go in for some manual adjustment on the mesh...

I might check Faro RevEng soon, guess I could check the PowerSurfacing RE too. Geomagic for Solidworks is about the same price as Faro's, so might not be a good deal. But as I checked again the PS RE it doesn't looks like a RE software, it's more about editing the mesh and have the standard SubD tools, right? For what I was searching RE software is more about identifying features, export sketches etc.

[Arthur NY]

So when selecting mesh areas to then convert to geometry, yes that starts to really get into full RE. But there are levels in-between needing Design X or Polyworks and Faro's software. Especially if maybe just needing to convert the data from a Mesh to BREP/NURBS.

I can say that zBrush does a better job in decimating geometry than ANY of these other softwares. When I say this I mean both in terms of reducing polygon count AND keeping the detail of the model and also reducing file size. (Geomagic Wrap, Magics, Design X, Rhino30 or Polyworks.) And here's something that zBrush does that the others miss out on..... a duplicate of the original high polymesh can be made, then decimated, and then reproject the details from the high poly mesh onto the low poly mesh. This last part is basically the process of that is more than just shrinkwrapping it is physically pushing the low poly geometry so that it better holds to the higher poly geometry.

In this last example this is a HUGE area that Rhino3D is missing out on. Once the geometry is converted from a mesh to BREP/Nurbs, there's no ability to have it hold a tighter tolerance to the original mesh. So while it does convert it there can be quite a loss of detail. So then one might say that upping the detail size/polycount of the conversion might do the trick and Rhino3D can really take a huge hit in performance when trying to achieve the same results that some of the other routes achieve with much less overhead.

I would NOT recommend the Geomagic Wrap for Solidworks Plug. Yes you are correct in that Power Surfacing RE is not doing full feature recognition in the same way as Design X. What it is helping to do is convert the data so that you can use all of the Solidworks functionality to then do that conversion.

I'll try to run a few examples and show some screen shots to post later in the week.

[Arthur NY]

Here are some screen shots showing some side by side information about scanning and details.

[AlexLachance]

Thanks for the share Lucas, always awesome to see different stuff!

[Lucas]

I can say that zBrush does a better job in decimating geometry than ANY of these other softwares. When I say this I mean both in terms of reducing polygon count AND keeping the detail of the model and also reducing file size. (Geomagic Wrap, Magics, Design X, Rhino30 or Polyworks.) And here's something that zBrush does that the others miss out on..... a duplicate of the original high polymesh can be made, then decimated, and then reproject the details from the high poly mesh onto the low poly mesh. This last part is basically the process of that is more than just shrinkwrapping it is physically pushing the low poly geometry so that it better holds to the higher poly geometry.

I never used zBrush, but I can agreed to that. lol
When I was checking Blender for decimating meshes the results were much better than using CAD software. Nevertheless, for scanned meshes with many holes and noises I wasn't getting good results, hence I switched to Magics since I was looking for a fast and reliable semi-automatic solution. (although Magics is a pretty expensive software too, but we have it due to the Build Processor of our printer)

Guess I will check Blender again and search for the equivalent zBrush tools. It is the Decimate Master plugin, right?

I hope Blender has this brush to preserve the mesh lol

Thanks for the share Lucas, always awesome to see different stuff!

Glad to share, I am also trying to learn this stuff.

[Lucas]

Here are my last results from December. I had to deal with other stuff this year and stopped the Scan tests :/

Bike Steam

Before and after Magics:

Rhino .Step in SolidWorks:

Final Result:

*This one I actually did not import the mesh in SolidWorks. I was measuring in PolyWorks and making everything without references.
It was pretty painful. lol

Garmin Mount (Cycling Computer)

Before and after Magics:

Final result:

[Lucas]

A Blender update

I was about to give up when I found out how useful the Remesh Modifier can be. lol

Basically it can reconnect the mesh if you start increasing the value of the Octree Depth (increasing the mesh density) and finding a sweet spot for the Scale.

*Sharpness and Threshold seems to not change anything in this case.
*don't forget to check Remove Disconnected like I did


Part analysis in Magics. Original vs Remeshed:

Afterwards I used the Decimate Geometry with a 0.05 Ratio:
(I selected everything, but it decimates locally; meaning that you could keep the details in some desirable regions)

With two semi-auto tools it basically fixed everything. Pretty amazing :0
Original
56.0k Verts
106.8k Faces
106.8k Trits

Remeshed
146.8k Verts
146.8k Faces
293.7k Trits

Remeshed and Decimated
7.3k Verts
14.1k Faces
14.7k Trits



With Merge by Distance and Inverting selection of unconnected vertex plus delete, final clean up:

*I am still missing stuff, it's being a while that I don't use Blender... But this is good enough to import to SolidWorks or print. lol

[berg_lauritz]

Just slightly related:
One of our designers uses Rhino & he is at least (!) 5x as fast in changing things as we are. We often get solids from him that we have to convert to SolidWorks files because of PDM & for CNC optimization. I do envy him for having those great surfacing & direct editing capabilities.

We are looking into getting a 3D printer & from what I have heard you can easily do it in Rhino... If I could switch to that program... I would, I think.

[Lucas]

Just slightly related:
One of our designers uses Rhino & he is at least (!) 5x as fast in changing things as we are. We often get solids from him that we have to convert to SolidWorks files because of PDM & for CNC optimization. I do envy him for having those great surfacing & direct editing capabilities.

We are looking into getting a 3D printer & from what I have heard you can easily do it in Rhino... If I could switch to that program... I would, I think.

Yep, it's pretty fun to design surface in Rhino. Although I might say that when it comes to Fillets and Drafts SolidWorks is much more powerful.