Re: [osg-users] Trouble with LightSpacePerspectiveShadowMap artifacts.
Hi, Dario 0: Ops I was sure these methods are available Thats awkward ommission considering how old this technique is. We probably should add them. But as a temporal workoaround you can derive your own class from LispSM and add proper setter and getter for polygon offset... 1: Yes closed was not a stric term but you got it right: cube is closed in this definition and single quad is not. 2: Yes you can. Assuming the vertices are oriented properly and it not change how it looks of course. Cheers, WL 2012/8/28 Dario Minieri para...@cheapnet.it Hi, Thanks for your reply. Yes, I see now the polygonoffsetfactor and polygonoffsetunits variables even if there are no methods to set them (osg 3.0.0), they are setted as attribute camera StateSet because shadow map generation. I can try to tweak these values in some way. You speaks about two stuffs which I would to discuss: 1. You say that the model must be closed, but what do you means precisely? Closed in term of vertex mesh or closed in terms of shape? For example a cube is a closed model, my truck obviously not... 2. I can set the cull faces on my objects stateset via GL_CULL_FACE, do you means that? Many thanks Thank you! Cheers, Dario -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49624#49624 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trouble with LightSpacePerspectiveShadowMap artifacts.
Hi Yes, polygonoffset methods are presents in ShadowMap class only, but I use a technique derived from StandardShadowMap which redefines the polygonoffset variables and here we have no methods to set. However, I've tried polygonoffset tweak and the final result is much better even if not perfect in all scenes. Thanks for your suggestions. However I will try the new robert's technique also in next days. I still have to try the the GL_CULL_FACE option in my models... Best Regards Wojtek wrote: Hi, Dario 0: Ops I was sure these methods are available Thats awkward ommission considering how old this technique is. We probably should add them. But as a temporal workoaround you can derive your own class from LispSM and add proper setter and getter for polygon offset... 1: Yes closed was not a stric term but you got it right: cube is closed in this definition and single quad is not. 2: Yes you can. Assuming the vertices are oriented properly and it not change how it looks of course. Cheers, WL 2012/8/28 Dario Minieri () Hi, Thanks for your reply. Yes, I see now the polygonoffsetfactor and polygonoffsetunits variables even if there are no methods to set them (osg 3.0.0), they are setted as attribute camera StateSet because shadow map generation. I can try to tweak these values in some way. You speaks about two stuffs which I would to discuss: 1. You say that the model must be closed, but what do you means precisely? Closed in term of vertex mesh or closed in terms of shape? For example a cube is a closed model, my truck obviously not... 2. I can set the cull faces on my objects stateset via GL_CULL_FACE, do you means that? Many thanks Thank you! Cheers, Dario -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49624#49624 (http://forum.openscenegraph.org/viewtopic.php?p=49624#49624) ___ osg-users mailing list () http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org (http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org) -- Post generated by Mail2Forum -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49669#49669 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trouble with LightSpacePerspectiveShadowMap artifacts.
Hi, Dario, LispSM is setup by default to cast shadows using light space backfacing polygons. That approach works well if models are closed and build with face culling in mind. If your model does not utilize cull faces (and your truck looks like that case), all front polygons will cast shadows. So the artifact you see is false self shadowing on front polygons. To work around that you will have to switch the sign of polygon offset factors and maybe further tweak polygon offset factors magnitude if your field of view gets big. You will find current polygon offset values in StandardShadowMap setup code. There is a method to set new polygon offset for the technique. PS: I highly recommend reading some papers on principles of ShadowMaping. There is a Mark Kilkgard presentation on the web that explains many of the problems. Cheers, Wojtek Lewandowski 2012/8/28 Dario Minieri para...@cheapnet.it Hi! Nice to hear for the new your technique, I will try today checking the svn. Is a ShadowMap tech, so the shaders are the same of StandardShadowMap.cpp file? Meantime, I attach a debug shadow snapshot with CAST and NOCAST setted on terrain. I'm not sure to understand well the result...the artifacts are the same in both cases, but the depth calculation seems to be different to me...You can see some specific stuffs? Thanks again for your suggestions. Best regards robertosfield wrote: Hi Dario, On 27 August 2012 17:13, Dario Minieri wrote: I've tried to use the CASTS_SHADOW_TRAVERSAL_MASK on my terrain but the final result is pretty the same. Code: GfxTerr-setNodeMask(m_GfxTerr-getNodeMask() ~CASTS_SHADOW_TRAVERSAL_MASK); Run the debug shadow view to see if it's taking into account the terrain. Or... just try the ViewDependentShadowMap technique that now is available in svn/trunk. This new technique is more robust than LispSM and offers similar functionality w.r.t projections. It may or may not solve your problem, but as I'm the author of this particular technique I have a better chance of understand and helping address the issues. I'm not the author or or the implementator the OSG's LispSM technique so am a bit of disadvantage here. Robert. ___ osg-users mailing list http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Post generated by Mail2Forum -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49608#49608 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trouble with LightSpacePerspectiveShadowMap artifacts.
Hi, Thanks for your reply. Yes, I see now the polygonoffsetfactor and polygonoffsetunits variables even if there are no methods to set them (osg 3.0.0), they are setted as attribute camera StateSet because shadow map generation. I can try to tweak these values in some way. You speaks about two stuffs which I would to discuss: 1. You say that the model must be closed, but what do you means precisely? Closed in term of vertex mesh or closed in terms of shape? For example a cube is a closed model, my truck obviously not... 2. I can set the cull faces on my objects stateset via GL_CULL_FACE, do you means that? Many thanks Thank you! Cheers, Dario -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49624#49624 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trouble with LightSpacePerspectiveShadowMap artifacts.
Hi, I've tried to use the CASTS_SHADOW_TRAVERSAL_MASK on my terrain but the final result is pretty the same. Code: GfxTerr-setNodeMask(m_GfxTerr-getNodeMask() ~CASTS_SHADOW_TRAVERSAL_MASK); hummmartifacts don't go away... Thank you! Cheers, Dario -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49585#49585 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trouble with LightSpacePerspectiveShadowMap artifacts.
Hi Dario, On 27 August 2012 17:13, Dario Minieri para...@cheapnet.it wrote: I've tried to use the CASTS_SHADOW_TRAVERSAL_MASK on my terrain but the final result is pretty the same. Code: GfxTerr-setNodeMask(m_GfxTerr-getNodeMask() ~CASTS_SHADOW_TRAVERSAL_MASK); Run the debug shadow view to see if it's taking into account the terrain. Or... just try the ViewDependentShadowMap technique that now is available in svn/trunk. This new technique is more robust than LispSM and offers similar functionality w.r.t projections. It may or may not solve your problem, but as I'm the author of this particular technique I have a better chance of understand and helping address the issues. I'm not the author or or the implementator the OSG's LispSM technique so am a bit of disadvantage here. Robert. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trouble with LightSpacePerspectiveShadowMap artifacts.
Hi Dario, The issue looks like one of depth precision of the shadow map such that the depth test makes an erroneous judgment about whether the front surface is in shadow or not, this often is a surface self shadowing itself. The normal solution is to use a polygon offset in the shadow map generation so that the surface doesn't shadow itself, if this polygon offset is too small you still get the self shadowing artifact if the value is too large you no longer get shadows where you should see them. The better the depth precision of the shadow map the lower the polygon offset will be required, and in your case perhaps it's the ground layer that is very large and it part of the shadow casting scene to pushes out the depth range of the shadow map reducing it's precision. If this is the case then using the Cast/RecivesShadowMask functionality would be appropriate as this will you could use the mask to avoid the ground being used in the shadow map generation. Robert. On 24 August 2012 14:57, Dario Minieri para...@cheapnet.it wrote: Hi, I'm using a shadowed scene with LightSpacePerspectiveShadowMapCB technique with a single light. I've seen that in some positions of the camera, the shadows appear artifacts, while in other positions not. See snapshots. Moving the camera in a continuous manner, this results in an annoying shadows flickering on the objects. You have some kind of idea for that? GLSL Shadow shader issue? Graphix card issue? Other? Thank you! Cheers, Dario -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49505#49505 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trouble with LightSpacePerspectiveShadowMap artifacts.
Hi Thanks robert for your suggestion, yes this seems the case, the terrain is very very large. I wiil try your suggestion soon. Thanks! Bye! robertosfield wrote: Hi Dario, The issue looks like one of depth precision of the shadow map such that the depth test makes an erroneous judgment about whether the front surface is in shadow or not, this often is a surface self shadowing itself. The normal solution is to use a polygon offset in the shadow map generation so that the surface doesn't shadow itself, if this polygon offset is too small you still get the self shadowing artifact if the value is too large you no longer get shadows where you should see them. The better the depth precision of the shadow map the lower the polygon offset will be required, and in your case perhaps it's the ground layer that is very large and it part of the shadow casting scene to pushes out the depth range of the shadow map reducing it's precision. If this is the case then using the Cast/RecivesShadowMask functionality would be appropriate as this will you could use the mask to avoid the ground being used in the shadow map generation. Robert. On 24 August 2012 14:57, Dario Minieri wrote: Hi, I'm using a shadowed scene with LightSpacePerspectiveShadowMapCB technique with a single light. I've seen that in some positions of the camera, the shadows appear artifacts, while in other positions not. See snapshots. Moving the camera in a continuous manner, this results in an annoying shadows flickering on the objects. You have some kind of idea for that? GLSL Shadow shader issue? Graphix card issue? Other? Thank you! Cheers, Dario -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49505#49505 ___ osg-users mailing list http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Post generated by Mail2Forum -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=49522#49522 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
