Celestia Forums

This is a new system Im working on incorperating comets as pulsar jet streams...Wish I could change the color of comet tails but oh well this will have to do...



Opinions are welcome...

Heres where I am getting my data...

http://home.xtra.co.nz/hosts/Wingmakers/Pulsar%20Planetary%20System%201257+12.html

Wow! That looks fantastic, great work!

Hey thanks...I couldnt sleep tonight so I decided to make the system now...Its not that big a file and it includes JPG format...All you need to do for certain ones in the ssc file is switch the texture designation with the rem #...

Also this includes an update to the starnames.dat file so if your current one includes changes you may want to extract to the desktop first and add this line in yourself...

300002:PSR1257

Needs to be there or the pulsar wont have planets

filename: psr1257.zip on the server...

Fix for this system...

http://www.shatters.net/~rassilon/psr1257.stc

Problem is how do I specify a neutron star as with the stars.dat?

eg:

The high four bits (12 - 15) of the stellar class field are the star type:
Normal: 0
White dwarf: 1
Neutron star: 2
Black hole: 3

And a black hole for that matter...

As best I can tell from the source code, the stellar class designations used by Celestia are
White Dwarf = "WD"
Neutron Star = "Q"
Black Hole = "X"
with no spectral subclass or luminosity suffix.

See
http://cvs.sourceforge.net/cgi-bin/view ... cvs-markup

Hey thx selden that helped alot...

when will this one be up for download?

It already is...

Update for those files...The complete zip has been updated with even newer fixes...or if you like just download psr1257fix.zip for just the updates...extract psr1257fix.zip to Celestia/extras folder...

All files are located on the server in my signature next to My Files:

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love it. my only gripe is the spectral class. you have it as an F-type star, but neutron stars (and therefore pulsars) are variable, and thus are classified usually as either just 'variable' or as 'RR Lyrae' stars. don't know if you can change this.

erostosthenes,

You need to download Ras' fixes: "Class: Q" is Celestia's notation for pulasrs. That's all that's programmed into Celestia right now. I suspect now that people are actually using it, however, that Chris mibht add a few qualifiers like being able to specify the rotaional speed, etc.

Another note on what I make...Alot of times my creations will be hacks to make the appearence of something that works and not nessicarily 100% correct as with Celestia itself there are alot of things that arent 100% correct...eg emissive objects shouldnt project shadows...should have thier own temprature and what not....Were all doing our best to give you up to date Celestial bodies and/or imaginary ones...In other words I have to work with what I got ...And alot of times I dont know all the variables...Thats why chris set up this forum so we could all learn from each other...

Ok Ive adjusted the stc file again...The RA I realised tonight is in degrees not hours...so PSR1257+12 is now in its correct position in the sky...Both main file and fix file have been updated...jeez I hope this is the last fix lol

OK well I guess I might as well turn this one over to you Rassilon. I was working on it, but I couldn’t make adding a star work for me, so here it is. This is a real nasty one, but I think you might like it. A REAL Rouge Black Hole! (Ok technically they still are not sure, but there is a 99% that it is one.)

Here in did all the homework for you.

"XTE J1650-500" a stellar black hole with the approximate mass of 10 suns
RA 252.5041667 # 16h 50m 01s.0
Dec -49.9625 # -49o 57' 45" (J2000.0, error=2")
Distance 26000ly
Radius 15k
Absolute visual magnitude of -2

This is how I was gong to create it. I might give you some ideas for future projects

I was going to make a star with the correct brightness, but a small radius. I was then going to place a larger planet object on top of the star, fully covering it. I would make the default planet pure black, and then add a thin light red atmosphere for the Hawking radiation effect. Place two Pulsar Jets (comets) for the poles of the black hole. Then finally add a ring for the gas and matter falling into the black hole. The ring would star at the surface of the event horizon, and extend for about 1 AU or so.

I don’t now if this is even possible, but hey.

You may get some ideas from the black hole that is available on Bruckner's site:
http://bruckner.homelinux.net/addons.html

i tried laying two meshes on top of eachother and it wasn't pretty. from some angles you could see the inner one underneath the outer one.

Ive done something like this before with sucess...Overlapped a redder texured emissive planet over a star to give the appearence of the star being darker...Problem with those current values MKruer is Celestia has a culling problem with stars past 16k ly distance from sol...Chris has mentioned that he wants to fix this but also is having issues with OpenGL allowing that to be completed...He may have to recode the star structure entirely so we may not see a fix for this for a few versions...I can however place it just within the 16k boundry if that will suffice?

eros wrote:i tried laying two meshes on top of eachother and it wasn't pretty. from some angles you could see the inner one underneath the outer one.

Thats somewhat affected by alternate starlight...If you notice when you rotate the star in question path across a distant star viewed at a certain distance...that happens yes...I think when chris adds in binary/trinary starlight support we may not see this anymore...But theres also the problem with objects made bigger than the allowed culling area of a solar system or star...They get clipped in places...eg models of nebulae when scaled around a star will appear 'clipped' when viewed up close...or when they are scaled too big they also clip when viewed from afar...

Ive noticed when masking a star with an emissive that the best thing to do is make the star with an stc file and make it as large as the emissive mask...the mask being a tad larger...clipping is then reduced...

Sure, you can try it. I would like to see it if for nothing else just to see it work.

BTW the 16kly limit wouldnt have anything do with celestia being in 32-bit?

MKruer wrote:BTW the 16kly limit wouldnt have anything do with celestia being in 32-bit?

Not at all . . .

It's an arbitrary size assigned to the root node of the octree structure I use for fast visibility checking of stars. It's no problem to change this value, but I want to investigate possible performance issues that may arise from using a larger number. It *shouldn't* matter at all, but I'm worried that I've overlooked something . . .

--Chris

Well you might want to try it this way. Create a trunk for Celestia that supports a higher node precision and just through it up as a beta exe so people can try it out. That way in anything breaks they still have the older version to work with. I am sure I am not the only one who wouldn’t mind trying “extended” version. And who knows it might fix some other issues. Your never know until you try.