Hi Adrien,
I'm having a slight problem understanding your questions, so I'll do my best
and ask some back...
>Would it be possible to add a ocean geometry and attach the ocean effect,
>shader. if yes how should it be look like, just a >plane? more complex
>geometry? My idea would be to add a lake surface, and two rivers with
>different waves, and so on.
Do you mean you would like to add you own method of generating the water
geometry for lakes and rivers?
If so, I've tried to accommodate for additional type of geometry by providing
the OceanTechnique base class.
Basically osgOcean is comprised of two main parts.
OceanTechnique: Which generates and animates the ocean geometry and manages any
level of detail algorithms that are required. It uses osg::Geode as a base
class and therefore drawables for the geometry. A class derived from this
should provide a water shader. Animation is provided by adding a cull/update
callback.
OceanScene: Which manages the various pre and post render passes required for
the effects. This also includes controlling the different types of fogging and
lighting that are applied based on whether the main camera view is above or
below the water surface.
If you want to create your own water geometry class you'll have to inherit from
OceanTechnique and then add this class to OceanScene as done with
FFTOceanSurface in the example application. OceanScene will only work with one
OceanTechnique so you'll have to create a new instance of OceanScene if you
wish to use multiple OceanTechniques. The geometry can be as complicated or as
simple as you like. If you apply the current water shader to a quad it still
looks alright and maybe be suitable for some applications.
These two papers provide very good explanations of generating water geometry
(the first is used in FFTOceanSurface):
http://graphics.ucsd.edu/courses/rendering/2005/jdewall/tessendorf.pdf
http://citeseer.ist.psu.edu/cache/papers/cs/26265/http:zSzzSzwww.cs.sunysb.eduzSz~ash
zSzwaterCGF.pdf/
The tricky part is the shaders. osgOcean provides a very long list of uniforms
which you can make use of if you wish in custom shaders. Some must be applied
locally to the OceanTechnique (see: FFTOceanSurface::initStateSet() ), and
those related to the multipass rendering are inherited from the statesets
within OceanScene (see: void OceanScene::init()).
The shader implementation used in FFTOceanSurface can be found in the resources
directory (water.frag/water.vert).
If you want to use this shader for your own technique you'll have to apply it
within your OceanTechnique and add the uniforms found in:
FFTOceanSurface::initStateSet().
Your best bet is to look at the FFTOceanSurface class and see how it's
implemented. It's not as complicated as it looks, 80% of it is to do with
generating the vertex array and primitives for the geomipmapping routine which
you may not need.
>we don't need only an unfinite ocean
You can disable infinite ocean effect using:
FFTOceanSurface::enableEndlessOcean(false,true);
>Next problem i got is that the default motion models are not working
Do you mean the ocean waves aren't moving?
I hope that answers your questions, otherwise I've just gone off on a very
lengthy tangent :)
Kim.
From: osg-users-boun...@lists.openscenegraph.org
[mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Adrian Egli
OpenSceneGraph (3D)
Sent: 19 June 2009 06:22
To: OpenSceneGraph Users
Subject: [osg-users] osgOcean : Integration into existing Database /Application
Hi all
i am wondering how i can integrate the osgOcean effect into existing
application, database. Would it be possible to add a ocean geometry and attach
the ocean effect, shader. if yes how should it be look like, just a plane? more
complex geometry? My idea would be to add a lake surface, and two rivers with
different waves, and so on. finally we don't need only an unfinite ocean. Next
problem i got is that the default motion models are not working, i played
arround with osgviewer example, and osgOcean example. Well how should we use
both ideas together in a terrain database (currently existing, but without the
nice water effect)
/regards adrian
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Adrian Egli
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