Board index FlightGear Development Aircraft

Red propeller disk under certain light conditions

Questions and discussion about creating aircraft. Flight dynamics, 3d models, cockpits, systems, animation, textures.

Red propeller disk under certain light conditions

Postby gsagostinho » Sun Mar 18, 2018 11:17 pm

Hi all,

Perhaps someone here will be able to shed some light on this issue (pun intended). The propeller disk of our c172p turns to red under certain light conditions and we aren't sure if this is something caused on our side or if this is something caused by FG itself. This is how it looks:

Image

To reproduce it, load the c172p at dusk and with ALS on. Choose the advanced weather preset "low pressure system" and then slowly move the time forwards using the key t in your keyboard. At a certain time, the disk will turn red.

So my question is: is this caused by something we did in the development of the c172p or is this issue affecting other aircraft as well? Has anyone observed it with other propeller aircraft?

Many thanks!
Gilberto
User avatar
gsagostinho
 
Posts: 1800
Joined: Thu Jan 15, 2015 6:27 pm
Location: London, UK

Re: Red propeller disk under certain light conditions

Postby gsagostinho » Sun Mar 18, 2018 11:33 pm

Starting to look like this is on our side: the c182s and the c152 do not get a red propeller after dusk. Any ideas about the cause would be appreciated! :)
User avatar
gsagostinho
 
Posts: 1800
Joined: Thu Jan 15, 2015 6:27 pm
Location: London, UK

Re: Red propeller disk under certain light conditions

Postby wlbragg » Mon Mar 19, 2018 2:12 am

I figured out the solution but not the cause exactly. Something to do with Blender's material settings.
Kansas(2-27-15)/Ohio/Midwest scenery development.
KEQA (2-27-15), 3AU, KRCP Airport Layout
User avatar
wlbragg
 
Posts: 4885
Joined: Sat Aug 25, 2012 11:31 pm
Location: Kansas (Tornado Alley), USA
Callsign: WC2020
Version: next
OS: Win10/Debain/nVGT640

Re: Red propeller disk under certain light conditions

Postby Thorsten » Mon Mar 19, 2018 6:16 am

The question is probably related to what effect you use to render the disc.

If you happen to assign a legacy effect like model-transparent or chrome, you get the non-ALS light computation which has a red component quite long after the sun is below the horizon - if the rest of the scene is dark enough, you get to see it in this way.

It might also be a quality thing - some of the low-end ALS effects borrow specular light from the default renderer - which is mostly okay and allows to slash quite some computation cycles, but fails at low light.
Thorsten
 
Posts: 10969
Joined: Mon Nov 02, 2009 8:33 am


Return to Aircraft

Who is online

Users browsing this forum: Google [Bot] and 29 guests