How to subtract width/length of rectangle/box toward pivot point (e.g. towards center)

Grasshopper
#1

When I’ve got a rectangle/box, how can I subtract a specific width/length towards a pivot point. I’m working on a Grasshopper file for a cabinet. Currently the doors (in my Grasshopper file) use all the space between de side frames of the cabinet. I want to give them ~3mm space around all edges.

I’m aware that I can do this when I construct the rectangle, i.e. by simply providing different x/y values, but I’m curious if it’s also possible to resize a rectangle/box after it’s been created?

I’ve created this basic rectangle:

image
image1277×537 37.2 KB

And the file:
grasshopper-experiment-subtract-size-towards-center-v1.gh (6.5 KB)

#2

Not sure how you want to use this but have you considered Offset Curve?

offset_crv_2021Jun1a
offset_crv_2021Jun1a843×340 52 KB

offset_crv_2021Jun1a.gh (7.0 KB)

#3

If I understand you correctly, this should do what you want:

image
image1366×866 144 KB

image
image1222×690 12.7 KB

grasshopper-experiment-subtract-size-towards-center-v1_re.gh (10.8 KB)

-Kevin

#4

Thanks @Joseph_Oster this was exactly what I needed!

#5

Thanks @kev.r although this is the more correct answer to my question … and really good to know about, but the solution from @Joseph_Oster worked for me as well.