Celestia Forums

Here is a celURL showing Jupiter eclipsing Io:Sun Side

Here it is from the opposite side of Io (ambient light = medium) : Other side (Near L2 point)

Is the eclipse shadow supposed to appear on the far side of Io??

svn 4585

HERE is a link to a video of this scene , in case you cannot replicate the effect that I am seeing.

Note also the strange jagged edges on the shadow.


CC

Sorry: Chris has said he does not plan to do anything about either of the issues that you mention.

1. Shadows are drawn correctly only if ambient light is set to 0.

2. jagged edges are due to low resolution shadow masks being used. This problem is eliminated in the OpenGL 2.0 render path.

OK, thanks Selden.

selden wrote:1. Shadows are drawn correctly only if ambient light is set to 0..

0 == "None" I assume.

Chuft-Captain wrote:OK, thanks Selden.

selden wrote:1. Shadows are drawn correctly only if ambient light is set to 0..

0 == "None" I assume.

In addition to the Render menu none/low/medium values, you can adjust the ambient light level by typing the { and } keys, wich show the level as values between 0.00 and 1.00

selden wrote:In addition to the Render menu none/low/medium values, you can adjust the ambient light level by typing the { and } keys, wich show the level as values between 0.00 and 1.00

Thanks Selden. Of course I know that already...(I was just playing dumb.)

From memory, I believe Low = 0.3 and Medium = 0.7.

Dunno if it might help anyone else here, but I also have an issue
with Ambient Light...

When I first start Celestia, my ambient light setting is set to
the medium level, but my planets, and many other objects, are
displayed so that they show up featuring waaaay too much
brightness.

If I go to the Ambient Light settings and first set the level to "None,"
and then reset the level to "Medium," my brightness problems are
solved - at least until I re-start Celestia.

Just throwing this information into the conversation in case it may
be of use to others here.

Thanks, Brain-Dead

I would have expected the Ambient Light value to be preserved when Celestia exits and restarts.

What happens when you set the ambient light level using the keyboard commands { and } ? Do those values stick when you exit and restart Celestia?

selden wrote:I would have expected the Ambient Light value to be preserved when Celestia exits and restarts.

What happens when you set the ambient light level using the keyboard commands { and } ? Do those values stick when you exit and restart Celestia?

Selden,

I lowered the Ambient Light value using the keys, and then exited the program
and re-started it. The new values were apparently saved, because the Ambient
Light level was set to "Low" when I re-started Celestia.
Even though this was the case though, the brightness problem was still evident.
When I did as I described previously, the brightness problem went away again.

Just FYI...

Thanks, Brain-Dead

Bob:

Ambient light can be controlled and pre-set by a cel or celx script. It is possible you have your start.cel or start.celx calling an ambient light level higher than 0. This would of course, overrule the last light level that your closed Celestia with, and open the program with the new level called. For example, in the celx script I use in my educational activities to open Celestia (called "slowergo-start-ed.celx", I open Celestia with ambient light set to 0.05. Here is the line to look for in the start script:

set {name "AmbientLightLevel" value 0.05}

FYI

Frank

fsgregs wrote:Here is the line to look for in the start script:
set {name "AmbientLightLevel" value 0.05}

Thanks for that information, Frank. Apparently, I still don't have my
Nvidia card set up correctly. I just tried to update the drivers, and I
ended up having to restore my system to an earlier time in order to get
it functioning again.

After playing around some more, I did get the latest release installed, but
the process was a total mystery to me until I got through it once.

The uninstall of the previous drivers gave me the most trouble, with
Nvidia's uninstaller sitting there apparently doing nothing for 20 minutes.
After I clicked on the screen image it started to uninstall, but this also took
some investigation into the FAQ's before I learned exactly what I should have
been uninstalling.

Boy, whatta headache.

At any rate, I'm finally updated, and everything seems to be working
correctly. The first time I did this, I thought I had gotten an old ATI
update. The Earth lost its textures, and nothing worked right.
If you don't know what you are doing here, this process is dangerous.

Word of warning to other Brain-Dead users.

Okay, I finally got it figured out...

I needed to change the AmbientLight value contained in my start.cel file.

After I modified it as follows, my brightness problems went away.
set {name "AmbientLightLevel" value 0.3}

I still don't know why setting the value to "none" and then back to "Medium"
reset the display though.

Oh well, sorry for the confusion.
Thanks, Bob

selden wrote:Sorry: Chris has said he does not plan to do anything about either of the issues that you mention.

1. Shadows are drawn correctly only if ambient light is set to 0.

2. jagged edges are due to low resolution shadow masks being used. This problem is eliminated in the OpenGL 2.0 render path.

The OpenGL 2.0 also draws shadows correctly even when the ambient light isn't set to 0.0.

--Chris