Help: How do I translate a group?

  • J.Smith

    J.Smith - 2009-06-03

    I'm building a BRL-CAD model of a very small town with cars, people, houses, etc.  I already have binary database files for the the cars, people... basically all of the stuff that I want to put into the model.  Now I'm trying to figure out how to move and position things around as I set up the layout of the town. 

    So I have a little house binary file and in my model I want to make a curving row of 5 of these houses along a curving street.  I don't want to instance them either since I might make unique changes to each house later on. 

    So my question is how do I do this.  I want to something like the "tra" command except my house isn't a primative, its a group with windows, doors, a patio, etc.

    Thanks for all the help.

    • J.Smith

      J.Smith - 2009-06-03

      Got it figured out...I wasn't selecting the matrix properly before commanding the transforms.  all better. thanks

    • Sean Morrison

      Sean Morrison - 2009-06-03

      Glad you got it figured out.  For what it's worth, the 'tra' command also works on object editing, but you have to specify where to apply the matrix edit.  That's where the 'oed' command becomes important or the "Edit -> Matrix Selection" menu option in the GUI.

      There is specific tutorials aimed at both of those in the documentation on the website at

      The "Object Editing - the oed Command" covers the oed command; the "Introduction to MGED" tutorial series covers using the menu option.

      Basic use is something like this:

      oed / object_to_edit/then/path/to/some/primitive
      tra 100 0 0

      That will translate object_to_edit by 100 units in the x-direction.  See the tutorial for why the 'then/path/to/some/primtive' part is required. ;-)



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