Does extrude() have a hidden definition.symmetric option?

Jonathan_Hutchinson

As per the title - if passing '.symmetric' and the other things such as 'hasSecondDirection', 'secondDirectionBound' etc, will this create a symmetric extrude?

I've added a symmetric option to a tool I've been writing but have seen curious behaviour where I didn't even need to halve my depths as expected. The creating feature happened to have a symmetric option, and was passed downstream, and I feel like I have just accidentally added the symmetry option that way (despite not seeing it documented).

Stormi_Backus

In my experience, adding .symmetric parameters to an extrusion automatically splits your chosen extrude depth in either direction. So you'll want to give it full depth rather than half. 

As for hasSecondDirection and secondDirectionBound, I haven't used them but these parameters meant for non-symmetric extrusions so you will have to manually enter the desired distance to extrude in either direction. 

Hopefully that helps!

Jonathan_Hutchinson

Thank you! Yeah so I added a boolean parameter called definition.symmetric, which was then passed in later to an extrude command. I had initially thought specifying those other parts were doing what I wanted, until I started getting half distances for the symmetrics. But I've searched again and again, it's totally undocumented?

EvanReese

I may not understand what's hanging you up, but you can look here at the actual extrude feature code, and see what's available on the definition. Just think of it as using the native feature, but using your own UI and automations to control it, so the behavior should be the same. In this case, the behavior of the native feature is to make the total depth equal to your distance when "symmetrical". It also ignores anything you feed it about the "secondDirection" when it's "symmetrical".

Jonathan_Hutchinson

Wasn't so much a hang up - more that I stumbled upon it by accident, and then wondered why my 'half' distances were becoming quartered. Kept on checking and double checking that the map to feed to extrude() didn't have an option for symmetric in it. Thankfully the penny dropped eventually that it was purely coincidence because my feature using extrude had symmetric in the definition.

Is it odd that I would've expected 'definition > symmetric > type:boolean' to be here? To me it just seems inconsistent to be required to dig into extrude.fs and there are twice as many places options could be, although that's ultimately the lesson learnt. What other useful stuff is hiding?