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Author Topic: Light pulse stopped working  (Read 7037 times)

Atreus

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Light pulse stopped working
« on: May 04, 2011, 04:43:15 PM »
The light pulse was working last night when I was going through the tutorials, but now it's not.

I set the time to real-time, zoom in on the solar system until Venus is orbiting about the width of my desktop, and click light pulse.

Nothing happens.  Framerate drops to 7 fps, but no light pulse is emitted.  Help?  I can even do the "Speed of light" tutorial and the light pulse doesn't show up.

Dan Dixon

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Re: Light pulse stopped working
« Reply #1 on: May 04, 2011, 04:48:29 PM »
Hmmm... Strange.

Are you running in Universe Sandbox 'Safe Mode' by chance?

Can you see Saturn's rings?

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Try giving your computer a restart.
And make sure your video drivers are up to date.

Let me know what happens either way...

Atreus

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Re: Light pulse stopped working
« Reply #2 on: May 04, 2011, 05:03:38 PM »
Safe mode?  Not sure.  I don't think so... How would I check?

And as for Saturn's rings..... ...no o.O  Not when I click on the Our Solar System scenario...

Atreus

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Re: Light pulse stopped working
« Reply #3 on: May 04, 2011, 05:26:56 PM »
Well, I had the latest drivers anyways... But a restart seemed to fix it.  that's strange...  Saturn's rings are still gone though.

Edit: Wait, no, not working again.
« Last Edit: May 04, 2011, 06:07:00 PM by Atreus »

Dan Dixon

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Re: Light pulse stopped working
« Reply #4 on: May 05, 2011, 12:50:17 AM »
Are you running the Steam version or the non-Steam version?

Atreus

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Re: Light pulse stopped working
« Reply #5 on: May 05, 2011, 12:54:52 AM »
Steam version.  Bought it last night.

Other specs: Windows 7 32-bit, 4 gigs RAM, Nvidia Geforce GTS 250

Dan Dixon

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Re: Light pulse stopped working
« Reply #6 on: May 09, 2011, 02:35:39 PM »
Are you still having this problem?

That's the same video card I use to develop on... So that's not it. :)

Are you getting any warnings about the dust multiplier?

Atreus

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Re: Light pulse stopped working
« Reply #7 on: May 09, 2011, 02:38:13 PM »
I've been busy with uni, so I haven't been able to try since.  But I wasn't getting any errors about dust multipliers.

Lazareth

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Re: Light pulse stopped working
« Reply #8 on: May 09, 2011, 09:49:46 PM »
I have had this or a similar problem sporadically where the light pulse doesn't seem to work. While frustrated I kept clicking the light pulse button many times quickly and suddenly noticed an increasingly bright white line all around the horizon. I quickly figured that this was the light pulse, which for some reason got spawned at a ridiculous distance and when I spawned multiply of them they became noticeable, probably due to increase density of the particles. They also seemed to simply "hang" there for the rest of the simulation and no matter how much I zoomed out they didn't seem to get closer.

However I haven't had this problem since the last update. Since it was sporadic I have no idea if it is gone for good or just being fickle. I do think it happened about the same time as the placement bug (which was also sporadic for me) and that haven't happened since either.

Dan Dixon

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Re: Light pulse stopped working
« Reply #9 on: May 10, 2011, 01:51:28 PM »
They also seemed to simply "hang" there for the rest of the simulation and no matter how much I zoomed out they didn't seem to get closer.

Keep zooming out.

Something traveling at light speed multiplied by a large time step is going to travel really far, really fast.
If you zoom out enough, you'll see that it's a huge and continually expanding ring.

Try the "Light speed" activity again to see how to properly slow down time.

feo

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Re: Light pulse stopped working
« Reply #10 on: July 10, 2011, 09:35:56 AM »
hi,
i got a very similar problem. the light pulse doesn't work if i open a simulation (for example the tutorial where it is explained). though if i start a new empty simulation, add a sun and a planet the light pulse will work.
i checked the time stepping double, so this isn't the problem.

i'm using the steam-version and a win7(64bit) system with a radeon5750 and phenom2 x4.

Dan Dixon

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Re: Light pulse stopped working
« Reply #11 on: July 10, 2011, 02:15:04 PM »
That's odd and I'm unable to duplicate this problem. Is anyone else seeing this?

1
Are you sure your time step isn't so high that they fly off so fast that you're just missing them?

2
Are you using the "Real Time" setting?

3
Try opening up Galaxy Collision and shoot off a light pulse from a galaxy. Does that work?

feo

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Re: Light pulse stopped working
« Reply #12 on: July 11, 2011, 05:16:15 AM »
found out something new...if i change to the accuracy mode the light pulse isn't working...going back to normal mode it's working again.

btw: by testing it on the "saturn and moons"-simulation i discovered that all objects are being catapulted away from saturn when setting the time step to 1 day per step. is this a known bug or why is that?

SplAdamB

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Re: Light pulse stopped working
« Reply #13 on: June 11, 2012, 06:59:18 AM »
I had this same problem with the steam version and a radeon 6850, seems light pulses don't work with the RK4 math. Use normal accuracy, just have to decrease the frame times if you want to make up for the accuracy, I've had this thing simulating for a week before. Wished it used more of my processor.