A volcano on Io

Post #41by **chris** » 18.05.2007, 09:59

Here's my attempt with a point sprite cmod. It could still use some work, but I think it's cool nonetheless:

I placed all of the volcanoes in volcanopele's table. The add-on is here: http://www.celestiaproject.net/~claurel/celest ... canoes.zip It will only work with the latest version of Celestia built from CVS. One neat thing is that the volcanoes are all properly shadowed by Io. You can watch the base of the plumes slip into darkness as Io rotates, followed eventually by the tops. And everything goes dark when Jupiter casts its shadow across Io.

--Chris

Post #42by **t00fri** » 18.05.2007, 10:11

nice

Bye Fridger

Post #43by **ElChristou** » 18.05.2007, 10:34

chris wrote:Here's my attempt with a point sprite cmod. It could still use some work, but I think it's cool nonetheless:

Not bad at all...

It would be nice to see a merge between Chris model and Cham or Bugg's one...

ANDREA · Post #44by **ANDREA** » 18.05.2007, 11:05

ElChristou wrote:
chris wrote:Here's my attempt with a point sprite cmod. It could still use some work, but I think it's cool nonetheless:
Not bad at all... It would be nice to see a merge between Chris model and Cham or Bugg's one...

Absolutely I agree with Chris (ElChristou):
if possible, a merge of all the different systems seen up to now from Cham, Buggs and Chris could be the perfect one, if this will be possible without spoiling the efficiency of average graphic cards. :wink:

Bye

Andrea

buggs_moran · Post #45by **buggs_moran** » 18.05.2007, 11:24

WOW.. Point sprites are going to be incredibly useful. Those are beautiful Chris.

Fenerit · Post #46by **Fenerit** » 18.05.2007, 12:10

What one can say now? I've not words.

Cham · Post #47by **Cham** » 18.05.2007, 15:29

chris wrote:Here's my attempt with a point sprite cmod. It could still use some work, but I think it's cool nonetheless:

It would be usefull, except that it's hard crashing my whole computer !

Because of this, I completely abandonned my entire project of accretion disks and nebulae with Mathematica. :evil:

buggs_moran · Post #48by **buggs_moran** » 18.05.2007, 15:49

This sprite method could be particularly useful in modeling the geysers on Enceladus too.

Post #49by **t00fri** » 18.05.2007, 19:41

While usually, I am not the greatest fan of add-ons, this Io-vulcano stuff is really cute.

So I wonder whether it is really so hard to animate the eruptions in some way. I am thinking for example of Runar's amazing solar add-on where the prominences where beautifully animated. Runar just put some cmods in orbit as far as I remember...

Bye Fridger

volcanopele · Post #50by **volcanopele** » 18.05.2007, 19:44

Nice, but I am not sure the plumes should be that bright. To the naked eye, these would appear dark blue. You should be barely able to pick them out when against the disk of Io with the best times to see them when the the vent is near the bright limb and the plume is against dark sky (like Zal in one of your images), or when the vent is near or just beyond the terminator (like Prometheus in that same image). The plume should be barely visible when viewing a fully lit Io and brighten as you increase phase angle.

So I am not sure this method is best way to make plumes on Io, but I am sure they would make great star clusters!

I should revise the lat and lon of the Amirani plume vent to 21 North, 115 West based on the graphics you've presented.

danielj · Post #51by **danielj** » 18.05.2007, 20:03

What do you mean with "last build form cvs"?I unzip the "volcanoes" to Extras and I couldn??t see anyone in Io.Then I copied the ssc to extras,the texture "blob.jpg" to textures and the "plumes.cmod" to Io.It??s no use.What went wrong?
I am using the "original" Celestia 1.5.0 pre2...

Post #52by **t00fri** » 18.05.2007, 20:08

danielj wrote:What do you mean with "last build form cvs"?I unzip the "volcanoes" to Extras and I couldn??t see anyone in Io.Then I copied the ssc to extras,the texture "blob.jpg" to textures and the "plumes.cmod" to Io.It??s no use.What went wrong?
I am using the "original" Celestia 1.5.0 pre2...

As usual it means that you should download the latest CVS code and compile it. Then things will work.

Apparently nothing for "Endusers". They need more patience...

Bye Fridger

Post #53by **chris** » 18.05.2007, 20:48

volcanopele wrote:Nice, but I am not sure the plumes should be that bright. To the naked eye, these would appear dark blue. You should be barely able to pick them out when against the disk of Io with the best times to see them when the the vent is near the bright limb and the plume is against dark sky (like Zal in one of your images), or when the vent is near or just beyond the terminator (like Prometheus in that same image). The plume should be barely visible when viewing a fully lit Io and brighten as you increase phase angle.

So I am not sure this method is best way to make plumes on Io, but I am sure they would make great star clusters!

I agree that they're too bright . . . I can easily adjust them them so that they're dimmer, though the phase dependence would require some sort of basic scattering shader. That wouldn't be difficult to code, but some thought would be required as to how to integrate it into Celestia. It's not just an issue for scattering particles: there are other places where an alternative photometric function is useful, such as Lommel Seeliger for the Moon.

I should revise the lat and lon of the Amirani plume vent to 21 North, 115 West based on the graphics you've presented.

Thanks. I'll update the add-on.

--Chris

ANDREA · Post #54by **ANDREA** » 18.05.2007, 22:57

chris wrote: I agree that they're too bright . . . --Chris

Chris, I installed the latest available cvs (dated 30-Apr-2007 11:26 3.5M from http://www.purebytes.de/stuff/celestia/) over Celestia 1.5.0pre2, and then installed in extras your iovolcanoes.zip
I see the volcanic plumes (too many altogether, but it's easy to modify the ssc file, so no problem) but the problem I have is that while the plumes appear very (too much!) bright when far away from Io, as I go closer and closer the luminosity reduces drastically, up to reach almost to zero when at about 300 Km from Io.
The only remaining thing are the tiny spreaded points, almost invisible on the surface.
So I don't see them as showN in your close-up images.
In My Humble Opinion (hope that Fridger will appreciate my extended wording instead of acronyms :wink:

) it's a problem of mine, perhaps due to my cvs that's not the latest one? :oops:

Thank you for the info.
Bye

Andrea

buggs_moran · Post #55by **buggs_moran** » 18.05.2007, 23:31

t00fri wrote:While usually, I am not the greatest fan of add-ons, this Io-vulcano stuff is really cute.

So I wonder whether it is really so hard to animate the eruptions in some way. I am thinking for example of Runar's amazing solar add-on where the prominences where beautifully animated. Runar just put some cmods in orbit as far as I remember...

Bye Fridger

That's basically what I have done...

One thing that would be nice to see is parametric cyclical motion. That way we can define the paths and move an item across them over and over.

volcanopele · Post #56by **volcanopele** » 18.05.2007, 23:57

Cham wrote:It would be usefull, except that it's hard crashing my whole computer !

Yeah, I'm in the same boat as you. I just tried this out (with the latest CVS release I could find, same place as ANDREA got it), and my computer took a nose-dive. I may need to use a simpler model for my setup.

ANDREA wrote:too many altogether, but it's easy to modify the ssc file, so no problem

He is using the ones I listed above, but you are right, not all those maybe visible in daylight (due to a lower amount of entrained dust contained within the plume). If need be, people can excise the Illyrikon Regio and Hephaestus Patera plumes, which have only been seen when Io was in eclipse.

Another thing I thought about is that one could set time limits on these plumes in order for some of the Galileo-era plumes to show up during the Galileo-era and New Horizons-era plumes to show up now.

Post #57by **chris** » 19.05.2007, 00:15

volcanopele wrote:
Cham wrote:It would be usefull, except that it's hard crashing my whole computer !
Yeah, I'm in the same boat as you. I just tried this out (with the latest CVS release I could find, same place as ANDREA got it), and my computer took a nose-dive. I may need to use a simpler model for my setup.

There's some sort of problem with point sprites on the Mac, and I haven't been able to figure out what it is. I'm inclined to believe that it's a driver problem--at the very least, there's nothing I'm doing that should bring down a computer completely.

Another thing I thought about is that one could set time limits on these plumes in order for some of the Galileo-era plumes to show up during the Galileo-era and New Horizons-era plumes to show up now.

Easily done . . . I'll have a go of that this weekend unless someone beats me to it.

--Chris

Post #58by **chris** » 19.05.2007, 00:17

ANDREA wrote:
chris wrote: I agree that they're too bright . . . --Chris
Chris, I installed the latest available cvs (dated 30-Apr-2007 11:26 3.5M from http://www.purebytes.de/stuff/celestia/) over Celestia 1.5.0pre2, and then installed in extras your iovolcanoes.zip
I see the volcanic plumes (too many altogether, but it's easy to modify the ssc file, so no problem) but the problem I have is that while the plumes appear very (too much!) bright when far away from Io, as I go closer and closer the luminosity reduces drastically, up to reach almost to zero when at about 300 Km from Io.
The only remaining thing are the tiny spreaded points, almost invisible on the surface.
So I don't see them as showN in your close-up images.

That version lacks a recent fix that corrects some scaling problems with point sprites. 1.5.0pre3 will be out soon though.

--Chris

danielj · Post #59by **danielj** » 19.05.2007, 01:16

Does it mean that even the endusers will be able to see the volcanoes in Io?In Celestia 1.5.0 pre3?

chris wrote:
ANDREA wrote:
chris wrote: I agree that they're too bright . . . --Chris
Chris, I installed the latest available cvs (dated 30-Apr-2007 11:26 3.5M from http://www.purebytes.de/stuff/celestia/) over Celestia 1.5.0pre2, and then installed in extras your iovolcanoes.zip
I see the volcanic plumes (too many altogether, but it's easy to modify the ssc file, so no problem) but the problem I have is that while the plumes appear very (too much!) bright when far away from Io, as I go closer and closer the luminosity reduces drastically, up to reach almost to zero when at about 300 Km from Io.
The only remaining thing are the tiny spreaded points, almost invisible on the surface.
So I don't see them as showN in your close-up images.

That version lacks a recent fix that corrects some scaling problems with point sprites. 1.5.0pre3 will be out soon though.

--Chris

Post #60by **dirkpitt** » 19.05.2007, 02:22

chris wrote:
volcanopele wrote:
Cham wrote:It would be usefull, except that it's hard crashing my whole computer !
Yeah, I'm in the same boat as you. I just tried this out (with the latest CVS release I could find, same place as ANDREA got it), and my computer took a nose-dive. I may need to use a simpler model for my setup.

There's some sort of problem with point sprites on the Mac, and I haven't been able to figure out what it is. I'm inclined to believe that it's a driver problem--at the very least, there's nothing I'm doing that should bring down a computer completely.

For me it always either 1) Crashes just Celestia, or 2) Hard-crashes the OS.
The problem only occurs on the OGL2 path and VBO's need to be enabled.
(2) happened when I also removed the texture declaration from the cmod. I saw this debug message in my system.log after I rebooted: "kernel[0]: ATIRadeon9700::wait_for_rb_space: Overflowed block waiting for FIFO space. Have 2, need 8. RBBM_STATUS 0x84116100".

I can try out a couple of other things if it'll help.