[osg-users] 32bit DEPTH for RTT

Trajce Nikolov NICK trajce.nikolov.nick at gmail.com
Mon Oct 24 07:04:32 PDT 2016 

Got a help offline from a friend on this ... So glad there are so cool
people on this list ...

Thanks all!

Nick

On Fri, Oct 21, 2016 at 3:54 PM, Trajce Nikolov NICK <
trajce.nikolov.nick at gmail.com> wrote:

> Hi readers to this thread ;-),
>
> I am close to resolve this but the math involved is a bit tricky for me to
> understand it right. And suddenly I can not send screenshots or videos
> publicly - maybe on private email to those willing to help.
>
> The story now is this:
>
> The environment is ECEF terrain, and I have light source. I am rendering
> to texture from this light source position/direction into a depth texture.
> The light matrix is computed now in view space, and is used against the
> view vertex in pixel shader, where the shadow projection is done. It gives
> non-flickering results, which is very good however the texture coords are
> wrong, and the missing part for me is the coorect texture coords
> computation from lightmatrix and vertex in view space.
>
> Any help is very appreciated !!!
>
> And thanks
>
> Nick
>
> On Thu, Oct 20, 2016 at 7:13 PM, Trajce Nikolov NICK <
> trajce.nikolov.nick at gmail.com> wrote:
>
>> almost there .. the flickering is gone, just the shadow texture lookup
>> coordinates are messed up when used view space matrix and vertex.
>>
>> This is the code for constructing the final matrix:
>>
>>  osg::Matrixf lmvpm =
>> lightMatrixInViewSpace * osg::Matrixf(camera->getProjectionMatrix()) *
>>         osg::Matrixf::translate(1, 1, 1) * osg::Matrixf::scale(0.5, 0.5,
>> 0.5);
>>
>> and the GLSL:
>>
>> vec4 projShadow = light.lmvpMatrix  * vVertexView;
>>
>>         vec4 uvzw;
>>         uvzw.xyw = projShadow.xyz;
>>         uvzw.z = light.occlusionLayer-1;
>>         float factor = texture( lightOcclusionTextureArray, uvzw );
>>
>>         fDiffuseColor *= factor;
>>
>> if you spot anything ...
>>
>> Thanks so much Glenn!
>>
>>
>> On Thu, Oct 20, 2016 at 6:52 PM, Glenn Waldron <gwaldron at gmail.com>
>> wrote:
>>
>>> Up vector doesn't really matter, so just pick one like:
>>>
>>> side = cross(view_vec, (0,0,1));
>>> up = cross(side, view_vec);
>>>
>>>
>>>
>>> Glenn Waldron
>>>
>>> On Thu, Oct 20, 2016 at 12:00 PM, Trajce Nikolov NICK <
>>> trajce.nikolov.nick at gmail.com> wrote:
>>>
>>>> Just last question .. What the 'up' vector would be now for making the
>>>> light matrix in view space?
>>>>
>>>> On Thu, Oct 20, 2016 at 5:39 PM, Trajce Nikolov NICK <
>>>> trajce.nikolov.nick at gmail.com> wrote:
>>>>
>>>>> Glenn,
>>>>>
>>>>> this worked ... :-) ... Thanks for the hint ...
>>>>>
>>>>> On Thu, Oct 20, 2016 at 5:02 PM, Trajce Nikolov NICK <
>>>>> trajce.nikolov.nick at gmail.com> wrote:
>>>>>
>>>>>> wops ..
>>>>>>
>>>>>> mx.makeLookAt(lightPosInViewSpace,lightPosInViewSpace+lightD
>>>>>> irInViewSpace,up)
>>>>>>
>>>>>> On Thu, Oct 20, 2016 at 5:00 PM, Trajce Nikolov NICK <
>>>>>> trajce.nikolov.nick at gmail.com> wrote:
>>>>>>
>>>>>>> Thanks Glenn,
>>>>>>>
>>>>>>> actually I was expecting this. I have the math to get the light
>>>>>>> direction in view space, just the construction of the light matrix in view
>>>>>>> space hurts my head a bit ( I missed that part of the class :-) )
>>>>>>>
>>>>>>> vec3 lightDirInViewSpace;
>>>>>>> vec3 lightPosInViewSpace;
>>>>>>> mx.makeLookAt(lightPosInViewSpace,lightPosInViewSpace+lightP
>>>>>>> osInViewSpace,up)
>>>>>>>
>>>>>>> Something like this?
>>>>>>>
>>>>>>> On Thu, Oct 20, 2016 at 4:04 PM, Glenn Waldron <gwaldron at gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> There's your precision loss, you can't do that with ECEF
>>>>>>>> coordinates or they will be truncated.
>>>>>>>>
>>>>>>>> Better idea: build your light matrix in view space on the CPU
>>>>>>>> (instead of world space), and then use it on the view-space vertex in the
>>>>>>>> shader. (You'll have to update it every time the camera moves, of course.)
>>>>>>>>
>>>>>>>>
>>>>>>>> Glenn Waldron
>>>>>>>>
>>>>>>>> On Thu, Oct 20, 2016 at 10:00 AM, Trajce Nikolov NICK <
>>>>>>>> trajce.nikolov.nick at gmail.com> wrote:
>>>>>>>>
>>>>>>>>> Hi Glenn,
>>>>>>>>>
>>>>>>>>> vec3 vVertex = vec3(gl_ModelViewMatrix * VertexMODEL);
>>>>>>>>> worldSpaceVertex = osg_ViewMatrixInverse * vec4( vVertex, 1.0 );
>>>>>>>>>
>>>>>>>>> Part of VP
>>>>>>>>>
>>>>>>>>> On Thu, Oct 20, 2016 at 3:52 PM, Glenn Waldron <gwaldron at gmail.com
>>>>>>>>> > wrote:
>>>>>>>>>
>>>>>>>>>> Nick, how did you calculate "worldSpaceVertex"?
>>>>>>>>>>
>>>>>>>>>> Glenn Waldron
>>>>>>>>>>
>>>>>>>>>> On Thu, Oct 20, 2016 at 9:13 AM, Trajce Nikolov NICK <
>>>>>>>>>> trajce.nikolov.nick at gmail.com> wrote:
>>>>>>>>>>
>>>>>>>>>>> hehe .. ok :-) .. Maybe you give me a hint.
>>>>>>>>>>>
>>>>>>>>>>> I have F+ lighting (written by a friend of mine) and I have
>>>>>>>>>>> extended it so local lights cast shadows (a bit of complex code -
>>>>>>>>>>> relatively actually, but for me it is ;-) ). Works well for flat terrains
>>>>>>>>>>> with reasonable sizes. I am trying to make it work with ECEF terrain (for
>>>>>>>>>>> testing I use osgearth). The debug code works just fine, I am seeing the
>>>>>>>>>>> renderings from the local lights are correct, so the light view matrix
>>>>>>>>>>> passed to the shader is correct, but getting z-fights with
>>>>>>>>>>> setInternalFormat(GL_DEPTH_COMPONENT); only. Here is my setup
>>>>>>>>>>> for the RTT (it is texturearray):
>>>>>>>>>>>
>>>>>>>>>>> http://pastebin.com/Nnc2iA1F
>>>>>>>>>>>
>>>>>>>>>>> With DEPTH32bit (really naive approach, I "was" thinking fast
>>>>>>>>>>> the increase of the DEPTH precision will solve this issue, just recently
>>>>>>>>>>> started with reading papers and I must admit I am not a "shadowing expert").
>>>>>>>>>>>
>>>>>>>>>>> Further, I am calculating the Light View Matrix and passing it
>>>>>>>>>>> to the shader - this one is correct as well, since I am seeing the light in
>>>>>>>>>>> the scene with the z artifacts as I mentioned .... and this is my GLSL
>>>>>>>>>>> snippet:
>>>>>>>>>>>
>>>>>>>>>>> http://pastebin.com/r2W0gh0L
>>>>>>>>>>>
>>>>>>>>>>> I am trying to get it done as simple as is ... meanwhile found
>>>>>>>>>>> this:
>>>>>>>>>>>
>>>>>>>>>>> http://developer.download.nvidia.com/SDK/10/direct3d/Source/
>>>>>>>>>>> VarianceShadowMapping/Doc/VarianceShadowMapping.pdf
>>>>>>>>>>>
>>>>>>>>>>> that looks promising and apparently should help with the Z
>>>>>>>>>>> issues.
>>>>>>>>>>>
>>>>>>>>>>> This is my story for now, any hints are highly appreciated !!!!!
>>>>>>>>>>>
>>>>>>>>>>> And thanks a bunch for so far!
>>>>>>>>>>>
>>>>>>>>>>> Cheers,
>>>>>>>>>>>
>>>>>>>>>>> On Thu, Oct 20, 2016 at 2:56 PM, Voerman, L. <l.voerman at rug.nl>
>>>>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> yes?
>>>>>>>>>>>> we use a variation on OpenSceneGraph\src\osgShadow\P
>>>>>>>>>>>> arallelSplitShadowMap.cpp
>>>>>>>>>>>> regards, Laurens.
>>>>>>>>>>>>
>>>>>>>>>>>> On Thu, Oct 20, 2016 at 2:35 PM, Trajce Nikolov NICK <
>>>>>>>>>>>> trajce.nikolov.nick at gmail.com> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> Hi Laurens,
>>>>>>>>>>>>>
>>>>>>>>>>>>> do you have experience with DEPTH32bit and shadowcomparation
>>>>>>>>>>>>> set to true - for shadow mapping?
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Thu, Oct 20, 2016 at 12:08 PM, Trajce Nikolov NICK <
>>>>>>>>>>>>> trajce.nikolov.nick at gmail.com> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> Hi Voerman,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Yes, GL_DEPTH_COMPONENT32 was what I was missing ... Thanks
>>>>>>>>>>>>>> a lot!
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Trajce
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> On Thu, Oct 20, 2016 at 9:25 AM, Voerman, L. <
>>>>>>>>>>>>>> l.voerman at rug.nl> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Hi Trajce,
>>>>>>>>>>>>>>> maybe this sniplet helps?
>>>>>>>>>>>>>>> _textureDepthBuffer = new osg::Texture2D;
>>>>>>>>>>>>>>> _textureDepthBuffer->setTextureSize(_width+2.0f*_width*_guardBandPercentage,
>>>>>>>>>>>>>>> _height+2.0f*_height*_guardBandPercentage);
>>>>>>>>>>>>>>> _textureDepthBuffer->setSourceFormat(GL_DEPTH_COMPONENT);
>>>>>>>>>>>>>>> _textureDepthBuffer->setInternalFormat(GL_DEPTH_COMPONENT32)
>>>>>>>>>>>>>>> ;
>>>>>>>>>>>>>>> _textureDepthBuffer->setFilter(osg::Texture2D::MIN_FILTER,os
>>>>>>>>>>>>>>> g::Texture2D::NEAREST);
>>>>>>>>>>>>>>> _textureDepthBuffer->setFilter(osg::Texture2D::MAG_FILTER,os
>>>>>>>>>>>>>>> g::Texture2D::NEAREST);
>>>>>>>>>>>>>>> _textureDepthBuffer->setShadowComparison(false);
>>>>>>>>>>>>>>> _textureDepthBuffer->setWrap(osg::Texture::WRAP_R,osg::Textu
>>>>>>>>>>>>>>> re::CLAMP_TO_EDGE);
>>>>>>>>>>>>>>> _textureDepthBuffer->setWrap(osg::Texture::WRAP_S,osg::Textu
>>>>>>>>>>>>>>> re::CLAMP_TO_EDGE);
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> // camera
>>>>>>>>>>>>>>> _colorDepthCamera = new osg::Camera;
>>>>>>>>>>>>>>> _colorDepthCamera->setStats(new osg::Stats("Camera"));
>>>>>>>>>>>>>>> _colorDepthCamera->setName("colorDepth");
>>>>>>>>>>>>>>> _colorDepthCamera->setClearMask(GL_COLOR_BUFFER_BIT |
>>>>>>>>>>>>>>> GL_DEPTH_BUFFER_BIT);
>>>>>>>>>>>>>>> _colorDepthCamera->setReferenceFrame(osg::Transform::RELATIV
>>>>>>>>>>>>>>> E_RF);
>>>>>>>>>>>>>>> // set viewport
>>>>>>>>>>>>>>> _colorDepthCamera->setViewport(0,0,_width+2.0f*_width*_guard
>>>>>>>>>>>>>>> BandPercentage,_height+2.0f*_height*_guardBandPercentage);
>>>>>>>>>>>>>>> _colorDepthCamera->setRenderOrder(osg::Camera::PRE_RENDER,0)
>>>>>>>>>>>>>>> ;
>>>>>>>>>>>>>>> _colorDepthCamera->setRenderTargetImplementation(osg::Camera
>>>>>>>>>>>>>>> ::FRAME_BUFFER_OBJECT);
>>>>>>>>>>>>>>> _colorDepthCamera->attach(osg::Camera::DEPTH_BUFFER,
>>>>>>>>>>>>>>> _textureDepthBuffer.get(),0,0,false,0,0); // depth
>>>>>>>>>>>>>>> _colorDepthCamera->attach(osg::Camera::COLOR_BUFFER,
>>>>>>>>>>>>>>> _textureColorBuffer.get(),0,0,false,_msaa,_msaa); // color
>>>>>>>>>>>>>>> regards, Laurens.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On Wed, Oct 19, 2016 at 11:15 PM, Trajce Nikolov NICK <
>>>>>>>>>>>>>>> trajce.nikolov.nick at gmail.com> wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Hi Community,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> anyone with clue how to set RTT osg::Texture with 32bit
>>>>>>>>>>>>>>>> DEPTH?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thanks a bunch as always!
>>>>>>>>>>>>>>>> Cheers,
>>>>>>>>>>>>>>>> Nick
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>>> trajce nikolov nick
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> _______________________________________________
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>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
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>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> --
>>>>>>>>>>>>>> trajce nikolov nick
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> --
>>>>>>>>>>>>> trajce nikolov nick
>>>>>>>>>>>>>
>>>>>>>>>>>>> _______________________________________________
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>>>>>>>>>>>>>
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>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> --
>>>>>>>>>>> trajce nikolov nick
>>>>>>>>>>>
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>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> trajce nikolov nick
>>>>>>>>>
>>>>>>>>> _______________________________________________
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>>>>>>>>> cenegraph.org
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
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>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> trajce nikolov nick
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> trajce nikolov nick
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> trajce nikolov nick
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> trajce nikolov nick
>>>>
>>>> _______________________________________________
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>>
>>
>> --
>> trajce nikolov nick
>>
>
>
>
> --
> trajce nikolov nick
>



-- 
trajce nikolov nick
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