Re: [osg-users] multiple views + instancing

[Robert Osfield]

Hi David,

You could write a custom subclass of osg::Geometry and override the
drawImplementation an do the cull and dispatch of the primitives and
instance count for each time the geometry is drawn, but do so in a
thread safe way such as my computing all the dynamic data on the fly.

The alternative would be to have two osg::Geometry, once for each view
and have a NodeMask for each osg::Geometry and have use a
Camera::CullTraversalMask for each view to select the appropriate one
for each context.


Robert.

On 15 November 2017 at 19:06, David Heitbrink  wrote:
> Right now I having problems setting unique uniforms and num instances on a 
> per view basis (camera).
>
> Right now I am using hardware instancing, with a scene with 1000's of 
> relatively complex objects, but only a handful of actual models. I was able 
> to encode index's to textures + position and rotation transforms into a 
> single texture buffer.
>
> To do the viewport culling for this I added "proxy" nodes, which are just 
> osg::group nodes, with a compute bound + cull call backs. The cull call back, 
> calls back to a class tracking which instances are visible in which view. 
> Each view has a group attach to it between the camera and the main scene. In 
> said group, the texture buffer object is attached here.
>
> The instanced models are further down in the scene graph. I in a draw 
> callback from camera, I update each models uniform for its offset into the 
> texture buffer, its instance count, plus texture buffer (transforms + some 
> options for the fragment shader).  All of this works great until I have 
> multiple cameras.
>
>  Basically I cannot figure out a good way of modifying the instance count + 
> offset uniform so I get unique values for each camera. Does anyone have some 
> advice for this?
>
> --
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=72391#72391
>
>
>
>
>
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Re: [osg-users] multiple views + instancing

[David Heitbrink]

I am using osg 3.4.0. I am in a position where I could switch to a newer build.

--
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=72392#72392





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