i want to render my PCBs with Keyshot. Therefore i have following work flow:
Using KiCad to create my layouts
Using FreeCad and KiCad StepUp to import the files
Exporting the CAD with tracks as an *.obj
Importing with Keyshot the above mentioned
My problem lies between step 1 and 2. When i import the created layouts i unfortunately get an insufficient result regarding the quality of i.e. the via polygons. This of course results also in a bad result of my renderings. Is there any adjustment which helps me to improve the results so the polygons are much smoother and less edgy?
I ran a couple of test and I noticed that StepUp reduces the quality of the copper features in comparison to fcad_kicad (maybe for speed, it definitely runs faster)
Fcad_pcb is a FreeCad macro that you can use to import the KiCad pcb directly into FreeCAD. It was initially developed for milling pcbs but has been extended to generate solid modelling of copper features for FEM modelling. You run if from within FreeCAD and it imports the KiCad board file directly.
Adding to what @John_Pateman said, fcad_kicad only imports the board and models the tracks and vias, without any 3D models for the components on it, the StepUp from @maui uses it internally (AFAIK) to import the copper geometries from the board (tracks, vias, etc.), my assumption is that in order to improve performance, the copper geometry is being simplified by StepUp but I donât really know it to be true, here maui (the author of StepUp) is the one that knows best.
First things to take note of:
⢠Tessellation means different things to the different FreeCad Workbench programmers - not a constant implementation across Workbenches. It changes and evolves with every release version.
⢠Preferences (FreeCad) are settable once a Workbench is loaded. Youâll need to try different settings to Understand what they do and to dial-in what outcome is best for youâŚ
At present, various prefâs for handling Arcs, Ellipses and Polylines can influence what you see (Graphically and what gets exported for various formats). Multiple settings and panels⌠Explore them and make a Table for testing them outâŚ
Currently (for me) the best approach when I need smooth Arcâs and Circles is to Plot DXF in Kicad and import into FreeCad. Then, I can âMake Face From Wires in the Part workbench (if I want them filled).
Screenshots below Pads, Via and Traces: Notice the difference in quantity of Line SegmentsâŚ
I have little access to a PC to check this issue ATM.
An other route could be to export your pcb as vrml and from there export it to obj (both are tesselated sw)
Hi @maui ! Have you had the time to check if somehow the resolution of the copper features is being reduced by KSU? is it something that can be changed in the configuration ?
Hi @der.ule
the code for tracks is based on an early release of fcad_pcb which used polygon instead of arcs.
I have then modified the code to speed up the building process and to reduce the file sizeâŚ
ATM it is not a simply task to align my code to the latest fcad_pcb release.
I will have a deeper look but it wonât be an immediate solution.
it should be fixed now⌠(I ported some of the fcad_pcb code)
I also added support for arc tracks and cutting external shape on castellated pads
It shouldnât be much heavier in file size.