[osg-users] Several RTT camera/shader issue(s) on multipass shading
Hellhound at binary-revolution.org
Sun Oct 7 01:38:42 PDT 2007
>A short comment before looking at any of the code ( can't open the zip ).
I've checked the zip File, it's working for me (i've open it with 7zip)
of using windows or Linux as OS. If you got anymore trouble with this
could send the zip-file to your private mail address separately, if you
The coords for the textureUnits are hard coded in the OSGObjects class,
define the quad and the hud objects. These are standard coords and there
be no problems with them:
osg::ref_ptr<osg::Vec2Array> texCoords = new osg::Vec2Array();
Thanks for the hint with the projection matrix. This could be the
problem, i will
check it later, if i got solved the main problem with the wrong camera view
definitions, which i could solve until yet...
I think this issue is the main problem i've. I don't understand why i
RTT object's if i use the ABSOLUTE camera view definitions.
Mihai Radu wrote:
> Hi Christian,
> A short comment before looking at any of the code ( can't open the zip ).
> >From the snippets you posted, it looks to me like the texture
> coordinates used for textureUnit 0 are not correct.
> If they are set with the geometry ( per vertex ), then the first part
> should work well, if they are either object-relative or eye-relative
> with a TexGen to calculate them, that requires some calculations in the
> vertex shader ( that are done automatically by the fixed-function
> pipeline ).
> Looking even more closely, I can see you are rendering to a single quad
> ( z values are 0 ), and the last line scales everything in the [0.0,1.0]
> range, from the usual [-1.0,1.0], something that is done with projective
> texturing ( see osgshadow example for the way _texGen is being scaled ).
> I think the only reason your second snippet is working is because you
> are using an identity matrix for the camera, if you were using anything
> else, your results would probably be off.
> summary: check the texture coordinates for the pass you are referring to :)
> Christian Heine wrote:
>> 2nd issue (Shader):
>> If i use in the vertex shader the values of the rendering pipeline with
>> the following
>> setups, the RTT result is shown like in the working screenshot. The blur
>> of the second pass is not effected but the shader executed (set color to
>> gl_Position = ftransform();
>> vTexCoord = gl_MultiTexCoord0;
>> If i use this simple code sniplet (used in RenderMonkey for Shadertest)
>> then the
>> RTT is moved to screen center and sized up where nothing is shown (See
>> vec2 Position;
>> Position.xy = sign(gl_Vertex.xy);
>> gl_Position = vec4(Position.xy, 0.0, 1.0);
>> vTexCoord = Position.xy *.5 + .5;
>> I couldn't be explain, why this simple snipplet occurs in such an
>> effect. There is
>> nothing special done ...
>> Thanks for any help,
>> best regards
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