Thanks for the suggestion.  I've been trying things and looking at OSG
code and have some more questions.

When I actually looked at the sortByState() method in RenderBin, it says
that it doesn't do anything, because state sorting is more expensive
than it is worth.  It also says: "The contents of the StateGraph leaves
is already coarse grained sorted, this sorting is as a function of the
cull traversal."

What does this mean?  My guess is that it refers to putting things into
RenderBins (using setRenderingHint() and any explicit render bins I
set).  Can anything else set stuff into render bins, or any other kinds
of sorting?
 
I did implement a NoSortRenderBin, but I'm not sure it does anything
different than the standard RenderBin calling sortByState().

If I don't change the sort mode (I think default is sort by state?),
don't call setRenderingHint() (so only one pass) and turn off depth
tests and writes, will I draw in order of a depth-first traveral of the
tree?  Or is there sorting or grouping somewhere else?

Thanks,
andy

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Paul Martz
Sent: Friday, May 18, 2007 4:20 PM
To: 'osg users'
Subject: RE: [osg-users] controlling ordering

> Sometimes we might want to control the ordering of how things 
> are actually drawn.  We have cases where we'd like things to 
> come out in the order in which they appear in a depth-first 
> traversal of the scene graph, with no zbuffer.  (Obviously, 
> this is a special case, usually just 2D.)
> 
> We can turn off the zbuffer, but how would we get OSG to not 
> sort into bins or re-order in any other way?
> 
> We have a SceneView and call cull and draw on it.

Well, the OSG way is to put things in a RenderBin. So, you could create
your
own custom RenderBin and then override the methods that handle sorting
so
that the sort is a no-op. Then change the StateSet that your scene graph
uses so that the CullVisitor places everything in this new custom
RenderBin.

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