On Nov 8, 2007 7:52 AM, Bassam Kurdali <<a href="mailto:bkurdali@freefactory.org">bkurdali@freefactory.org</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
think of them as sets of objects: an object can belong to multiple sets (set of<br>things that are renderable, sets of things that are chairs, set of<br>things that are made of wood)</blockquote><div> </div>Then perhaps it should be called "sets" instead of "layers". Why use a word that has misleading implicit meaning when a perfectly fine word exists that actually describes what it does which you use to describe what it actually does. :)
<br><br>Semantics aside, I think the ability to exclusively group things irrespective of the scene graph should exists as well as the currently existing arbitrarily grouping functionality labeled as "layers". <br>
<br>As the amount of complexity goes up in a scene it becomes more and more difficult to manage how they are organized and a system which automatically compartmentalizes said organization is very helpful IMHO. Not to say that other 3D applications have it right but they seem to see the need for both exclusive and inclusive ways to organize the scene. Maya for instance has "sets" which are able to take arbitrary objects as members as layers do in Blender. It also has a "partitions" function which makes it so sets put under it's jurisdiction are mutually exclusive of each other. They give a good example of a case in which it would be desirable in their help system. I'll site it here.
<br><p class="Paragraph">--<br>For example, suppose you're animating a cartoon
character's nose as he smiles and laughs. You added a cluster to
several CVs for adjusting the nose as he smiles and another cluster to
different CVs for adjusting the nose as he laughs. </p>
<p class="Paragraph">Creating the two clusters creates a set for each
group of CVs. Occasionally you want to move CVs from one set to the
other. When you move the CVs from one set to the other set, they remain
in the first set. You might not want the CVs in the first set because
they add undesirable deformations [because you are doubling up the influence] as you transform the cluster. </p>
<p class="Paragraph">To avoid this problem, you can create a partition and put both <font style="color: navy; background-color: rgb(255, 255, 153);">sets</font>
in it. [Clusters in Maya are dealt with as sets which contain arbitrary vertices and their weighting information.] The partition prevents one set from having members of another
set. When you move the CVs from the first set to the second set,
they're automatically removed from the first set.<br>--</p>3DS Max takes a similar approach to their layers system in which a group of objects added to one layer will be removed from the layer it used to belong to. This way there is no ambiguity about what layer an object lives in and the objects are sure to be just in the layer I meant them to be in. After all, once one peels a layer off an onion and eats it, one can't peel that layer off of the onion again and eat it, again. Max also provides the arbitrary groupings, and more importantly settings, of things through their "scene state" functionality which I mentioned earlier on this board. Also quite useful IMHO.
<br><br>Anyway, I'm sure it will take someone much more technically savvier then myself to implement such a thing but perhaps a Maya-like "partitions" approach would be least time consuming to implement. That way the currently existing functionality can stay the way it is but there will be a way to manage scene objects in a way that is mutually exclusive to each other.
<br><br>phong.<br>