[osg-users] How to properly transfer texture coordinates in geometric shaders in Shader #130 version?

[Chris Hanson]

I just wanted to add that it is a popular opinion among the industry that
Geometry Shaders were ill-conceived architecturally and suffer unsolvable
performance-blocking issues. There are alternatives of various forms which
have their own complexities, but just in case you run into perf problems
with GS, you should be aware of the situation. Here's a discussion (related
to Vulkan, but architecturally the same situation) that a lot of people
seem to cite:

https://www.reddit.com/r/vulkan/comments/91q0qx/do_geometry_shaders_still_suck/

On Sun, Dec 13, 2020 at 4:19 AM Trajce Nikolov NICK <
trajce.nikolov.nick at gmail.com> wrote:

> Hi,
>
> have a look here MuseOpenIG/Plugin-GPUVegetation at master ·
> CCSI-CSSI/MuseOpenIG · GitHub
> <https://github.com/CCSI-CSSI/MuseOpenIG/tree/master/Plugin-GPUVegetation> ...
> This is code for generating forests with geometry shaders. It might give
> you better clue
>
> On Sun, Dec 13, 2020 at 7:08 AM mirr... at gmail.com <mirro187 at gmail.com>
> wrote:
>
>> sorry, the screenshot is wrong. It should be  samplerU.
>> I'm basically not sure how to get texture coordinates into
>> Shader::FRAGMENT  in Geometric shaders.
>>
>>
>> 在2020年12月10日星期四 UTC+8 下午11:13:21<gwal... at gmail.com> 写道：
>>
>>> What error are you getting?
>>> I do see an undefined "samplerY" in there.
>>>
>>> On Wednesday, December 9, 2020 at 9:03:47 PM UTC-5 mirr... at gmail.com
>>> wrote:
>>>
>>>> env is win10 osg3.6.4 GTX1660
>>>> [image: QQ图片20201210095944.jpg]
>>>>
>>>> osg::ref_ptr<osg::Program> createProgram()
>>>> {
>>>>     osg::Program *program = new osg::Program();
>>>>     program->addShader(new osg::Shader(osg::Shader::VERTEX,vertSource));
>>>>     program->addShader(new
>>>> osg::Shader(osg::Shader::GEOMETRY,geomSource));
>>>>     program->addShader(new
>>>> osg::Shader(osg::Shader::FRAGMENT,fragSource));
>>>>     program->setParameter(GL_GEOMETRY_VERTICES_OUT_EXT, 3);
>>>>     program->setParameter(GL_GEOMETRY_INPUT_TYPE_EXT, GL_TRIANGLES);
>>>>     program->setParameter(GL_GEOMETRY_OUTPUT_TYPE_EXT,  GL_TRIANGLES  );
>>>>     return program;
>>>> }
>>>>
>>> --
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>> .
>>
>
>
> --
> trajce nikolov nick
>
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>


-- 
Chris 'Xenon' Hanson, omo sanza lettere. Xenon at AlphaPixel.com
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