Group (grp)

key: grp

type: S(C)*

  1. string: object name
  2. (C)* : objects (eg, msh, sphr, grp, etc.) that form the group.

Description

Mechanism for grouping objects together to form a modeling hierarchy.  For example all the geometry that forms a chair might be placed as children of a group named "chair".

Conventions

Deleting all groups and placing their children at the top level which not alter the geometry or material properties of the model, so its never necessary to use groups.  However the modeling hierarchy they create can be very useful when editting a model. 

Examples

grp "sphere and a quad"
  sphr "red sphere"
     lmbrtn rgb 0.8 0.2 0.2 end end
     0.0 0.0 0.0 1.0  % center,radius
  end
  msh  % a one quad mesh
  "" mtrlNm "mat" end
     vrtxPstn
       0.5 -0.5 0.0
       0.5  0.5 0.0
       -0.5  0.5 0.0
       -0.5 -0.5 0.0
     end
     vrtxUV    % used for texture mapping
       1.0 0.0
       1.0 1.0
       0.0 1.0
       0.0 0.0
     end
     qdrltrl
       0 1 2 3
     end
  end
end