kicad-developers team mailing list archive

[easyw <easyw@xxxxxxxxxxxx>]

Hi Mario, Cirilo and Kevin.

As Mario and Cirilo already pointed out, STEP format doesn't support 
transparency, reflection, and ambient lighting...
So you can add these properties to your model but when you export it to 
STEP, they all are gone.
This can be done in Rhino, FreeCAD or whatever CAD you may use, STEP 
model will always be without these properties...

> I imported an item in to FreeCAD and it came out the wrong size due to the units used in the original file. I thought it would be easy to just scale the item to the right size in FreeCAD but FreeCAD wouldn't let me do it. I found that the only way it might have let scale an object is by scaling a copy of the imported object where the copy is linked back to the original version, or something like that.
> Even something as simple as changing the size of an item was being made difficult in FreeCAD.
FreeCAD is a parametric mechanical modeler, so scaling should be not the 
right way to adapt a model...
FreeCAD as you already pointed out has a Clone feature that can be 
scaled... the nice thing is that clone object is linked to its parent 
and if the parent will be changed, the clone will adapt accordingly... 
This is not the only way to scale a model, you can use a GUI macro for 
example.

In general you shouldn't model your part scaled to be aligned to kicad 
internal 3D viewer, you should model your part in mm scaled 1:1 and then 
scale the WRL when exporting. In this way your STEP models will be 
correctly scaled to the real dimensions.

Moreover in FreeCAD the correct way to model a part is starting from 
sketches ... then your model can easily changed simply modifying the 
dimensions of the sketches... this is how a parametric modeler is working.
You can follow many youtube tutorials on-line and get support on FC forum.
FreeCAD can also be scripted to easily create 3D parts and kicad is 
already using most SMD models coming from this method.
https://github.com/KiCad/packages3D/

This is not to force to use FreeCAD at all, but just to pointed out that 
you need to spend some time using a tool before judging.

If you want to have a realistic rendering in kicad, as already pointed 
out, the best way is to model your part in scale 1:1 with mm and from 
there export your wrl part with all the nice properties, scaled 1/2.54
You can also export it not scaled and assign a scale factor inside the 
kicad_mod footprint, so you can avoid the scaling part.

here some tips to create a mechanical library
https://github.com/KiCad/packages3D/blob/master/README.md

Cheers
Maurice