[RESOLVED] Clouds reciving Cloud shadows

For topics related to the creation of simulation objects (SimObjects). This includes development of aircraft, ground, and maritime vehicles.
Locked
Seralia
Posts: 14
Joined: Fri Nov 16, 2018 4:53 pm

[RESOLVED] Clouds reciving Cloud shadows

Post by Seralia »

Hey Guys,
One short Question. Is it possible to deactivate that Clouds recieving Shadows like Buildings or Aircrafts etc.
This Option would be a huge help for anybody who had problems with fps impacts at dusk/dawn....

I want that Clouds only could cast shadows and dont recieve it.

cheers
Andre Würzburger
User avatar
Poppet
Posts: 2770
Joined: Sat Nov 01, 2014 4:12 pm

Re: Clouds reciving Cloud shadows

Post by Poppet »

Hello Andre

Welcome to the Prepar3D Forum.

Have you experimented with the Shadow Casting and Receiving Options via Prepar3D > Options - Lightning ?

Let us know how you get on
Seralia
Posts: 14
Joined: Fri Nov 16, 2018 4:53 pm

Re: Clouds reciving Cloud shadows

Post by Seralia »

Hey,
Of course, we are experiment every flight.... And the reason why we think that it is because it is only with dusk / dawn occurs even if the sun is already under the clouds and the clouds lit from below.

When the sun is under the clouds, they can only cast shadows on themselves.

if you then disable cloud shadow "cast" in the options, you get full fps again.

So it would be very helpful if you could disable the cloud cast shadows on themselves.

the clouds should continue to cast shadows on the terrain, but not on themselves

cast but not recieving

I hope you can understand that and understand what I mean

cheers
User avatar
Beau Hollis
Lockheed Martin
Posts: 2452
Joined: Wed Oct 06, 2010 3:25 pm

Re: Clouds reciving Cloud shadows

Post by Beau Hollis »

Thanks for the feedback. The clouds don't actually receive could-shadows, so there's no need to disable it. Unfortunately, the performance hit is coming from the act of casting. We use a technique called cascaded shadow mapping in which the scene from the perspective of the sun. All the objects that cast shadows must be rendered into each cascade view. The number and resolutions of these views depends on your shadow quality settings. At dawn/dusk, when you are looking toward the sun is the worst case scenario because there are so many clouds drawing into the shadow maps.
Beau Hollis
Prepar3D Software Architect
Seralia
Posts: 14
Joined: Fri Nov 16, 2018 4:53 pm

Re: Clouds reciving Cloud shadows

Post by Seralia »

Many thanks for this great explanation and answer. now i am a little bit more clever.
i hope there will be somewhere in the future a better way to cast shadows because it is a very hard impact of performance and a lot of people got this problem.
Are u maybe work on a better solution?

BTW, great job with the v4.4

thanks again

Cheers
Locked