Extrude a rect also did a subtract - how to prevent it?

RoatanBill
RoatanBill
in 3D Modeling

I extruded a rectangle (yellow) and the extrusion passed through an existing solid (green).

What I thought I would get is an interference pattern as a visual clue but the action did a subtract on the existing solid. All 4 pieces of the angle iron base were identical before the extrusion. Now two have cuts in their vertical sides.

I checked the EXTRUDE docs and saw no reference (that I understood) to change the behavior to not subtract, but to interfere. Is there a setting?

Comments

  • Knut Hohenberg
    Knut Hohenberg

    You need to set DMEXTRUDEMODE and PUSHPULLSUBTRACT to your liking.
    I guess the most intuitive setting for the former is 6, and 0 for the latter: This will allow you to DMEXTRUDE boundaries that lie on a solid's face to create holes or protrusions, without having to fear that you might alter other solids encountered on the way, and the same would apply if you DMPUSHPULL recognized boundaries.

  • RoatanBill
    RoatanBill

    Thank you. I'll look those setting up.

  • Eric Ratliff
    Eric Ratliff
    edited January 2022
    FYI...
    I did not find those two variables by searching in Settings. In version 22, Mechanical workspace, I did find DMPUSHPULLSUBTRACT works to prevent the subtraction. Set it to disabled.
  • Chiyan
    Chiyan
    Hi all,
    For PUSHPULL you indeed have a setting to prevent subtracting by setting DMPUSHPULLSUBTRACT to 0. For EXTRUDE, all options are shown in the commandline during the command. You can also use the Hotkey-assistant (indicated in red in the image) to switch between the options with the Ctrl-key. To not subtract from existing solid, use option Create.


    More info: https://help.bricsys.com/document?title=_guides/BCAD_3D_modeling/GD_creatingsolidsusingtheEXTRUDEcommand.html&documentVersion=V22

    Kind regards,
    Chi-Yan