Re: Planar shadows

One alternative for fixed-function pipeline is to put height-dependent
value in alpha channel and use alpha test to clip parts below the
ground.

Simon

On Wed, Sep 29, 2010 at 2:09 PM, Jeff Russell <[email protected]> wrote:
> You may still be able to clip without a shader - opengl has user clip planes
> available in some versions, check your docs.
>
> The alternative is you could not completely flatten your geometry, just
> "mostly" flatten it so that it appears flat enough. Then you can still have
> your matrix set up to keep the unwanted geometry below the ground plane, and
> the depth test against the ground geometry will take care of it.
>
> On Wed, Sep 29, 2010 at 3:57 PM, [email protected]
> <[email protected]> wrote:
>>
>>  Thanks but it's OpenGL 1.0 for BlackBerry and 1.1 for Android.  So far
>> my solutions is, well, don't push the rocks so far into the ground :)
>>
>> Leigh
>>
>> On 9/29/2010 11:53 AM, Jeff Russell wrote:
>> > Yes there is - clip your shadow geometry against the ground plane
>> > before it gets flattened. You can do this with the discard keyword in
>> > your shadow pixel shader.
>> >
>> > Jeff
>> >
>> > On Tue, Sep 28, 2010 at 9:25 PM, [email protected]
>> > <mailto:[email protected]> <[email protected]
>> > <mailto:[email protected]>> wrote:
>> >
>> >      Hi,
>> >
>> >     I have hooked up planar shadows for my Android Tank game using a
>> >     matrix
>> >     to project all geometry onto the ground. The game has the luxury of
>> >     having  a 2D battle field.  The problem is that I am using instanced
>> >     rocks that are randomly rotated and pushed into ground.  So now I
>> >     get a
>> >     reverse shadow projected from underneath.  Is there any way to get
>> > rid
>> >     of this?
>> >
>> >     Leigh
>> >
>> >
>> > ------------------------------------------------------------------------------
>> >     Start uncovering the many advantages of virtual appliances
>> >     and start using them to simplify application deployment and
>> >     accelerate your shift to cloud computing.
>> >     http://p.sf.net/sfu/novell-sfdev2dev
>> >     _______________________________________________
>> >     GDAlgorithms-list mailing list
>> >     [email protected]
>> >     <mailto:[email protected]>
>> >     https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list
>> >     Archives:
>> >
>> > http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list
>> >
>> >
>> >
>> >
>> > --
>> > Jeff Russell
>> > Engineer, 8monkey Labs
>> > www.8monkeylabs.com <http://www.8monkeylabs.com>
>> >
>> >
>> >
>> > ------------------------------------------------------------------------------
>> > Start uncovering the many advantages of virtual appliances
>> > and start using them to simplify application deployment and
>> > accelerate your shift to cloud computing.
>> > http://p.sf.net/sfu/novell-sfdev2dev
>> >
>> >
>> > _______________________________________________
>> > GDAlgorithms-list mailing list
>> > [email protected]
>> > https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list
>> > Archives:
>> >
>> > http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list
>>
>>
>>
>> ------------------------------------------------------------------------------
>> Start uncovering the many advantages of virtual appliances
>> and start using them to simplify application deployment and
>> accelerate your shift to cloud computing.
>> http://p.sf.net/sfu/novell-sfdev2dev
>> _______________________________________________
>> GDAlgorithms-list mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list
>> Archives:
>> http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list
>
>
>
> --
> Jeff Russell
> Engineer, 8monkey Labs
> www.8monkeylabs.com
>
> ------------------------------------------------------------------------------
> Start uncovering the many advantages of virtual appliances
> and start using them to simplify application deployment and
> accelerate your shift to cloud computing.
> http://p.sf.net/sfu/novell-sfdev2dev
> _______________________________________________
> GDAlgorithms-list mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list
> Archives:
> http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list
>

------------------------------------------------------------------------------
Start uncovering the many advantages of virtual appliances
and start using them to simplify application deployment and
accelerate your shift to cloud computing.
http://p.sf.net/sfu/novell-sfdev2dev
_______________________________________________
GDAlgorithms-list mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list
Archives:
http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list