Lights are enabled in Forward3D instead of putted back to what they were

ChicChic · Post by **ChicChic** » Tue Jun 23, 2020 5:18 pm

Hi all,

As the tittle said, in the code of Forward3D::collectLights the lights are setted to invisible for some stuff and putted back to... visible !!!
Instead of setted back to what they were... it brang a problem in my software so i've made a patch.

I upload the patch, it has been made from Ogre 2.1 commit 2dcab1a29414bf53fe25d0b8dad97715064fb07b and the problem also appear in Ogre 2.2...
If some devs agree with that patch it should be pushed...

Cheers

Post by **dark_sylinc** » Tue Jun 23, 2020 7:45 pm

Hi!

Great point!!!

Fix pushed.

The fix has also been backported to stable 2.2 and 2.1 branches.

Thanks for the fix!

ChicChic · Post by **ChicChic** » Wed Jun 24, 2020 8:54 am

Ok, nice !

(I haven't seen it was also in ForwardClustered too

)

Glad to help !

ChicChic · Post by **ChicChic** » Mon Jul 20, 2020 4:32 pm

Hello again,

I see that a very similar problem occurs in CompositorShadowNode::clearShadowCastingLights/CompositorShadowNode::restoreStaticShadowCastingLights with Light::setCastShadows ...

Is it possible to correct the issue the same way dark_sylinc ?

Post by **dark_sylinc** » Mon Jul 20, 2020 6:22 pm

Actually no.
Those functions you pointed to are for manually managing shadow map/lights and force Ogre to use associate a light with a specific shadow map.

A light that does not cast shadows being forced to be associated with a shadow map is a contradiction.

If you want to turn off shadow casting or disable a light that you manually forced to be associated with a shadow map; either unbind the light from that shadow map; or alternatively set the light power to 0, thus the light will still burn GPU and CPU power, but it will not visually affect the scene; and restore the light power when you need to enable it again.
You can use light->getUserObjectBindings()->setUserAny to save the old light power for later restoring it.

I understand it's not user friendly (quickly flipping setCastShadows is convenient) but the implications of the contradiction are complex to solve (we must skip the shadow map from being processed, there will be holes/gaps in the shadow map, new shaders must be generated which can cause stalls)

ChicChic · Post by **ChicChic** » Tue Jul 21, 2020 9:15 am

If you want to turn off shadow casting or disable a light that you manually forced to be associated with a shadow map; either unbind the light from that shadow map; or alternatively set the light power to 0, thus the light will still burn GPU and CPU power, but it will not visually affect the scene; and restore the light power when you need to enable it again.

That was the point of my problem, I use the CompositorShadowNode::setLightFixedToShadowMap to reuse existing shadow map from other workspace in order to save CPU/GPU time but when I disable a light (Light::setVisible) it caused visual problems for the other lights.
So I tried to use light power but CPU and GPU time were still burned.
Finally I wanted to disable shadow casting when I want to disable a light and here was my actual problem.

Ok so unbinding the light from the shadow map have solved my former issue.
I can reuse shadows from other workspace without any artifact, thanks !

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Lights are enabled in Forward3D instead of putted back to what they were

Lights are enabled in Forward3D instead of putted back to what they were

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Re: Lights are enabled in Forward3D instead of putted back to what they were

Re: Lights are enabled in Forward3D instead of putted back to what they were

Re: Lights are enabled in Forward3D instead of putted back to what they were

Re: Lights are enabled in Forward3D instead of putted back to what they were