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How to get rid of specular reflection spot without re-baking light?


It's been a while I'm trying to figure out how to get rid of specular reflection spot remaining on the surface after rotating dynamic directional light without needing to rebuild lighting.

Here is what I mean;

Before rotating dynamic directional light alt text

After rotating it alt text

Updating sky sphere material alt text

re-baking lighting alt text

I want to rotate the sun dynamically but this specular spot always remain at the initial sun position no matter if the dynamic directional light rotates afterward. I have tried working with sphere reflection captures but didn't help at all. The sun mobility is set to fully dynamic. Even increasing the sun minimum roughness value to 1 does not remove the spot.

Any help is appreciated.


Product Version: UE 4.18
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asked Jul 05 '18 at 09:22 AM in Rendering

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avatar image navid100 Jul 06 '18 at 07:11 AM


By bringing a sphere reflection capture below the surface, where is quite dark, the captured darkness from that area removed the scpecular spot above the surface. But it also killed all other existing specular reflections too.

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avatar image navid100 Jul 07 '18 at 07:43 AM

For closed areas, a sphere reflection capture can be useful to get rid of such specular spots, but for open areas I'm still looking for a way to fix that.

avatar image navid100 Jul 08 '18 at 07:20 PM

Any idea?

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As I know, specular spots generated by source radius/source length. Try to set them to 0.

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answered Jul 05 '18 at 09:56 AM

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avatar image navid100 Jul 05 '18 at 10:18 AM

There is no such settings for dynamic directional lights. LightSourceAngle in project settings only works for static directional lights.

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The resaon about that spot is because your sphere reflection capture is not updated after rotate the light. I think just delete the sphere reflection captue could sovle the problem.

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answered Jul 06 '18 at 09:21 AM

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avatar image navid100 Jul 06 '18 at 09:24 AM

I've tried it before. Didn't help at all

avatar image navid100 Jul 14 '18 at 04:11 PM

After some trial and error, I found that updating sphere reflections don't take effect unless the sky material is updated first. Updating a sphere reflection fixes the wrong specular reflection but the problem is sphere reflections can't be updated dynamically since they are static at run time. Now if I remove all the reflection captures, updating sky material alone doesn't fix it.

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try disabling by features in the view panel and see what is causing that spot ! then post the results you can also use the viewmodes .

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answered Jul 14 '18 at 12:21 PM

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avatar image navid100 Jul 14 '18 at 04:22 PM

by switching to reflection mode, it shows that the sun reflection appears to stay at its previous position unless the lighting is built or a sphere reflection capture is updated. But I want a dynamic solution to this issue

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