I am encountering an issue with importing and exporting a .step file. When I export the file as a STEP in Rhino and subsequently attempt to import or open it, new surfaces are generated that were not present originally. Could you provide any advice or tips to resolve this issue?
Thank you very much in advance, and best regards.
These are most likely surfaces where the trim fails. So the surfaces you see aren’t new, they are just untrimmed. Or not trimmed because the edges used for trimming somehow aren’t closed anymore which could be due to file tolerance.
Do you have the source of the *.step file as Rhino file? Where do your curves originate / How did you create the curves?
The model was generated with a Grasshopper script. I have attached it to my message. I had to split it into three scripts due to PC issues.
Unfortunately, I had to include the Rhino file as a WeTransfer link because it was too large. (At least in case it might be of interest.)
Schritt 01_Generieren der Fläche.gh (47.6 KB)
Schritt 02_Extrudieren und Erzeugen von Stufen.gh (7.7 KB)
Schritt 03_Erzeugen von Stufen.gh (9.4 KB)
What are you doing with fologram? I’m not using that plug-in.
What’s in the two containers on the left of the screenshot?
The points from which the elevation model was created were obtained online. The file consisted of point clouds.
I see. I cannot help you with Rhino 7 issues related to these point clouds. I’m on Rhino 8.
I’ll take a look at the second and third Grasshopper file now
Too bad, but thank you nonetheless.
So the second Grasshopper file is used to add the walls around your terrain. Saving the result doubles your file size. If performance is an issue, I would rather export the result or internalise it in the Grasshopper file so the Rhino files are a little smaller.
I like to work with referenced / linked files. Files are smaller and when it does not create duplicate geometries. In your case, the surface could be saved as a block.
What do you want do with the *.step file? Why does it need these horizontal contours / levels?
Yes, performance is definitely a huge problem.
The file is intended as a basis for CNC milling. For aesthetic reasons, the model should consist of steps rather than a smooth surface. I don’t actually need the horizontal contours /levels; they were only an intermediate step.
So using a flat end mill bit, couldn’t you just specify the levels in CAM?
That’s a good tip. Since I have never done milling before, I’m not entirely familiar with the process. However, I will look into this option more closely.
Thanks for your help.
Due to the high definition of the surface, the contours also have a lot of control points. You could rebuild the curves or possibly rebuild the surface before doing anything to it and everything would go a little quicker.
more important question, What is your end goal here?
Is the step export necessary or is there another way to approach this? (i.e shrink wrap and export stl or obj)
are you machining it, printing it, or doing some sort of analysis or rendering?
in terms of trouble shooting, I’d run selbad and see if anything lights up in the rhino model. Typically that will show you any problem areas.
Also, what step scheme are you using to export? I’d go with ap214cc2 automotive design and see if that changes anything.
one trick to help fix any “bad curves” is to run a curve boolean on them and pick the inside or outside carefully to keep, this will eliminate any self intersections which will 100% cause bad trims.
One last thing I’d think about is your tolerance, currently you are set to .001 meters for your tolerance… that’s pretty tight for a huge item… do you need that much or can you drop a zero, run fitsrf at .01 units and get a much lighter surface that is easier to work with?
I have several goals that I want to achieve with the model. It serves as a foundation for the later processing of an architectural design. From it, models will be printed with the 3D printer (which I almost forgot initially), milled with the CNC machine, and used for visualizations.
Maybe I am also expecting too much from it?
fwiw- here is your surface rebuilt at 500x500 uv deg intersected with an extruded plane and closed into a solid. 27 mb total as opposed to 885mb for your original file
kfix.zip (7.3 MB)
In that case, 100% shrinkwrap it and then cnc or print the mesh… it’ll make you life much easier.
The Rhino file the user posted is Rhino 7
he can grab a v8 trial for 90 days free.
I have now downloaded the trial version, and it will probably be time to buy the update after it expires. I have also tried a few things now. Unfortunately, without success so far.
At which point would you use the Shrinkwrap function? If I set the accuracy too high, the program loads for hours without success. If I run the function on coarser settings, I get a result with rounded edges.
But in any case, it’s a great new feature that will make many things easier.
Have you tried working with this file? It would really make sense to rebuild the surface first.
