Hi Viggo, You should be able to set things up using NodeMasks, as you could set the push/pop traversal mask via a cull callback that decorates each branch of your multipass.
Using osg::Switch would require to modify the switch during the cull traversal which is something you should avoid if you ever want to multi-thread multi-context rendering. Robert. On Thu, May 22, 2008 at 9:11 PM, Viggo Løvli <[EMAIL PROTECTED]> wrote: > Hi Eric, > > It looks to me like using the switch could be the solution for my needs. > I think that it would either have to be a switch, or a mask. > > An example of what I want to do could be written like this: > > Original part of my scene graph: > Root > | > +--Node_1 (Specifies a states and a fragment shader) > | | > | +--Node_2 (Specifies a geometry to be rendered) > | | > | +--Node_3 (Specifies another geometry to be rendered) > > Using the switch to make sure I can render the scene twice with different > shader: > Root > | > +--Switch > | | > | +--Node_1 (Specifies states and a fragment shader) > | | | > | | +--Node_2 (Specifies a geometry to be rendered) > | | | > | | +--Node_3 (Specifies another geometry to be rendered) > | | > | +--Node_4 (This is a clone of Node_1 where I have added a new > shader) > | | | > | | +--Node_2 (This is the same node as Node_2 above) > | | | > | | +--Node_3 (This is the same node as Node_3 above) > | | > Conclusion: > - The switch will let one scene render use Node_1 and another scene > render use Node_4. > > Using a mask to achieve the same effect: > Root > | > +--Node_1 (Specifies states and a fragment shader, MASK = 0x1) > | | > | +--Node_2 (Specifies a geometry to be rendered) > | | > | +--Node_3 (Specifies another geometry to be rendered) > | > +--Node_4 (This is a clone of Node_1 where I have added a new shader, > MASK = 0x2) > | | > | +--Node_2 (This is the same node as Node_2 above) > | | > | +--Node_3 (This is the same node as Node_3 above) > | > Conclusion: > - This should work as far as I have understood the mask system, and this > time I do not need the switch node. > - In this solution I would not need to alter the position of Node_1 in > the tree. > > It is essential for me to have a solution where I do not need to do any work > in between each time I render the scene. > > Viggo > > > > ________________________________ > Date: Thu, 22 May 2008 17:14:09 +0200 > From: [EMAIL PROTECTED] > To: [email protected] > Subject: Re: [osg-users] Rendering the scene multiple times with > differentshaders. > > I think use osg::Switch is right way to do. > > You can set a StateSet to any Node, then (correct me if I'm wrong) all > children will inherit the stateset. > > So, I think about a graph like this: > > > > Root > > | > > …. > > | > > Switch > > ___|______________________________ > > | | > > | > Node2->stateset(shader2) > > Node1->stateset(shader1) | > > |_________________________________| > > | > > | > > Rest of your graph > > …. > > > > So you can insert this kind of switch to any subgraph which use another > shader, you do not have to duplicates the rest of your subgraph since two > parents can have the same child. > > > > Another way (similar) is to use a simple group instead of the osg::Switch, > but let osg to choose the good branch via nodeMask. In this way, you do not > have to update your graph between to passes. > > > > I hope it helps you. > > > > Eric Z. > > > > ________________________________ > > De : [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] De la part de Viggo > Løvli > Envoyé : jeudi 22 mai 2008 15:57 > À : [email protected] > Objet : [osg-users] Rendering the scene multiple times with > differentshaders. > > > > Hi, > > My scene contains models that use one or many textures, some use vertex and > fragment shaders of different kinds. Complex but good looking :-) > > I need to render the scene many times each frame. > The first render is a normal one, so I need no change in textures, states or > shaders. > The second render is a multi target render. Here I need to change all the > fragment shaders that my scene uses. Each shader need to output data to each > render target. > > My question is: > - What is the best way to switch shaders on many models in my scene-graph? > > One way to do it is to put a shader on the top node and override all child > nodes, but that only works if the entire scene-graph renders with the same > shader. My scene uses different shaders, so overriding is not the solution. > > One idea I have is to parse through all scene graphs that I add to my world > and duplicate all nodes that sets a fragment shader. I could then create one > shader for the normal render and one for the multi target render. This would > require that I mask those nodes so that the correct ones are used in each > render. This will require me to write my own function for adding nodes to > the scene. > > Anyhow, I would be very happy if someone could guide me in the right > direction on this one. > > Regards, > Viggo > > > ________________________________ > > Si det direkte med Windows Live Messenger. Lei av å vente på svar? > > ________________________________ > Få Windows Live Messenger du også. Snakk gratis med tekst, telefoni og > video. > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
