Re: [osg-users] 回复： Re: multi translucent g eometry

2008-07-14 Thread Peter Wraae Marino 
Hi Rick,

I agree with Paul.

Turn off your z-buffer. If this effect is for thrusters then you should
perhaps look into additive blending
instead and this should create a better effect.. the more thrusters the
brighter the become.

A screenshot of your problem would help a lot (if possible).

regards,
Peter
http://osghelp.com


2008/7/14 Paul Speed <[EMAIL PROTECTED]>:

> I'm no expert in this area but have had to do some pretty weird things
> in the past to get transparency working right for some odd scenes...
>
> One thing you might try is to disable z-buffer writes (not tests) for
> the flares.  Depending on your blending, this can add other types of
> artifacts but I think in your case they will be very subtle... versus
> the z-fighting you are seeing.  (You will obviously want them to be
> drawn last just like normal transparency.)
>
> Just an idea...
> -Paul
>
> Rick Pingry wrote:
> > That reminds me of an issue I have not resloved yet.  Our space ships
> > have thruster engines and I use an image map with transparency and point
> > it back at the camera to make a pretty glow around it.  (First off, is
> > this the best way to do it?  I have thought that perhaps a shader would
> > work better, but I have not had a chance to learn about how to write
> > shaders yet.  So much to learn, so little time).
> >
> > Anyway, In some ships there are banks of engines, and it is pretty easy
> > to get the problem where these transparent images intersect with each
> > other, and you get depth sorting issues that way.  I did work out a way
> > to make these "engine flare images" point, rather than right at the
> > camera, all along parallel lines with the camera's line of sight, and
> > that helped tremendously, but you can still get in positions where the
> > images happen to line up along the same depth, and you see some funky
> > tearing and the like due to depth fighting.  Is there a way to handle
> > this better? Should I try to apply other bins to the different engines?
> > What are the rules wrt that?   It sounds like I need to read up on the
> > glDepth and osg::Depth.  Any other recommendations?  I was running into
> > problems rendering planet halos too.  Should the halo be in front of the
> > planet or behind it?  probably the same kind of thing going on.
> >
> > Regards,
> > -- Rick
> >
> > 2008/7/13 小 杨 <[EMAIL PROTECTED] >:
> >
> > Thanks! I'll try it!
> >
> > */Peter Wraae Marino <[EMAIL PROTECTED]
> > >/* 写道：
> >
> > Hi ?? (can't see your name),
> >
> > Are you sure zbuffer isn't falling for your 2nd geometry object?
> > Also
> > having equal depths is probably not a good idea? You need to
> > render your
> > objects from back to front order.
> >
> > When you have transparent objects you should set the stateset
> > stateset->setRenderBinDetails(10,"DepthSortedBin");
> > this will render the objects from back to front order...
> > but note they will not sort the polygons for the individual
> > geometry.
> >
> >
> >
> >
> > 2008/7/13 小 杨 <[EMAIL PROTECTED]
> > >:
> >
> > multi  translucent geometry   with equal depth but  alpha
> > value is not equal.
> >
> > when i render these geometry ,i can not see all geometry! Why
> ?
> >
> > Can everyone give me some advice!
> >
> > Thanks!
> >
> 
> > 雅虎邮箱，您的终生邮箱！ 
> >
> > ___
> > osg-users mailing list
> > osg-users@lists.openscenegraph.org
> > 
> >
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> >
> >
> >
> >
> > --
> > Regards,
> > Peter Wraae Marino
> >
> > www.osghelp.com  - OpenSceneGraph
> > support site ___
> >
> > osg-users mailing list
> > osg-users@lists.openscenegraph.org
> > 
> >
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> >
> >
> >
> 
> > 雅虎邮箱，您的终生邮箱！ 
> >
> >
> > ___
> > osg-users mailing list
> > osg-users@lists.openscenegraph.org
> > 
> >
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> >
> >
> >
> >
> > --
> >  >> Rick
> > Check us out at http://fringe-online.com/
> >
> >
> > 
>  >
> > __

Re: [osg-users] 回复： Re: multi translucent g eometry

2008-07-14 Thread Paul Speed 
I'm no expert in this area but have had to do some pretty weird things
in the past to get transparency working right for some odd scenes...

One thing you might try is to disable z-buffer writes (not tests) for
the flares.  Depending on your blending, this can add other types of
artifacts but I think in your case they will be very subtle... versus
the z-fighting you are seeing.  (You will obviously want them to be
drawn last just like normal transparency.)

Just an idea...
-Paul

Rick Pingry wrote:
> That reminds me of an issue I have not resloved yet.  Our space ships 
> have thruster engines and I use an image map with transparency and point 
> it back at the camera to make a pretty glow around it.  (First off, is 
> this the best way to do it?  I have thought that perhaps a shader would 
> work better, but I have not had a chance to learn about how to write 
> shaders yet.  So much to learn, so little time).
>  
> Anyway, In some ships there are banks of engines, and it is pretty easy 
> to get the problem where these transparent images intersect with each 
> other, and you get depth sorting issues that way.  I did work out a way 
> to make these "engine flare images" point, rather than right at the 
> camera, all along parallel lines with the camera's line of sight, and 
> that helped tremendously, but you can still get in positions where the 
> images happen to line up along the same depth, and you see some funky 
> tearing and the like due to depth fighting.  Is there a way to handle 
> this better? Should I try to apply other bins to the different engines?  
> What are the rules wrt that?   It sounds like I need to read up on the 
> glDepth and osg::Depth.  Any other recommendations?  I was running into 
> problems rendering planet halos too.  Should the halo be in front of the 
> planet or behind it?  probably the same kind of thing going on. 
>  
> Regards,
> -- Rick
> 
> 2008/7/13 小 杨 <[EMAIL PROTECTED] >:
> 
> Thanks! I'll try it!
> 
> */Peter Wraae Marino <[EMAIL PROTECTED]
> >/* 写道：
> 
> Hi ?? (can't see your name),
>  
> Are you sure zbuffer isn't falling for your 2nd geometry object?
> Also
> having equal depths is probably not a good idea? You need to
> render your
> objects from back to front order.
>  
> When you have transparent objects you should set the stateset 
> stateset->setRenderBinDetails(10,"DepthSortedBin");
> this will render the objects from back to front order...
> but note they will not sort the polygons for the individual
> geometry.
>  
> 
> 
>  
> 2008/7/13 小 杨 <[EMAIL PROTECTED]
> >:
> 
> multi  translucent geometry   with equal depth but  alpha
> value is not equal.
>  
> when i render these geometry ,i can not see all geometry! Why ?
>  
> Can everyone give me some advice!
>  
> Thanks!
> 
> 
> 雅虎邮箱，您的终生邮箱！ 
> 
> ___
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> 
> 
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> 
> 
> 
> 
> -- 
> Regards,
> Peter Wraae Marino
> 
> www.osghelp.com  - OpenSceneGraph
> support site ___
> 
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> 
> 
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> 
> 
> 
> 雅虎邮箱，您的终生邮箱！ 
> 
> 
> ___
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> 
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> 
> 
> 
> 
> -- 
>  >> Rick
> Check us out at http://fringe-online.com/
> 
> 
> 
> 
> ___
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

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Re: [osg-users] 回复： Re: multi translucent g eometry

2008-07-14 Thread Rick Pingry 
That reminds me of an issue I have not resloved yet.  Our space ships have
thruster engines and I use an image map with transparency and point it back
at the camera to make a pretty glow around it.  (First off, is this the best
way to do it?  I have thought that perhaps a shader would work better, but I
have not had a chance to learn about how to write shaders yet.  So much to
learn, so little time).

Anyway, In some ships there are banks of engines, and it is pretty easy to
get the problem where these transparent images intersect with each other,
and you get depth sorting issues that way.  I did work out a way to make
these "engine flare images" point, rather than right at the camera, all
along parallel lines with the camera's line of sight, and that helped
tremendously, but you can still get in positions where the images happen to
line up along the same depth, and you see some funky tearing and the like
due to depth fighting.  Is there a way to handle this better? Should I try
to apply other bins to the different engines?  What are the rules wrt
that?   It sounds like I need to read up on the glDepth and osg::Depth.  Any
other recommendations?  I was running into problems rendering planet halos
too.  Should the halo be in front of the planet or behind it?  probably the
same kind of thing going on.

Regards,
-- Rick

2008/7/13 小 杨 <[EMAIL PROTECTED]>:

> Thanks! I'll try it!
>
> *Peter Wraae Marino <[EMAIL PROTECTED]>* 写道：
>
>   Hi ?? (can't see your name),
>
> Are you sure zbuffer isn't falling for your 2nd geometry object? Also
> having equal depths is probably not a good idea? You need to render your
> objects from back to front order.
>
> When you have transparent objects you should set the stateset
>  stateset->setRenderBinDetails(10,"DepthSortedBin");
> this will render the objects from back to front order...
> but note they will not sort the polygons for the individual
> geometry.
>
>
>
>
> 2008/7/13 小 杨 <[EMAIL PROTECTED]>:
>
>> multi  translucent geometry   with equal depth but  alpha value is not
>> equal.
>>
>> when i render these geometry ,i can not see all geometry! Why ?
>>
>> Can everyone give me some advice!
>>
>> Thanks!
>>  --
>> 雅虎邮箱，您的终生邮箱！ 
>>
>> ___
>> osg-users mailing list
>> osg-users@lists.openscenegraph.org
>> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>>
>>
>
>
> --
> Regards,
> Peter Wraae Marino
>
> www.osghelp.com - OpenSceneGraph support site
> ___
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>
>
>  --
> 雅虎邮箱，您的终生邮箱！ 
>
>
> ___
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>
>


-- 
>> Rick
Check us out at http://fringe-online.com/
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