Saturn (8k) rings problem...

[JackHiggins]

Hey all, chris...

I assume that apart from me, the only people with this version of celestia are those who get the CVS updates regularly! Anyway, after I got the update with the fixed Callisto orbit, I see this with 8k rings for Saturn. (Image name is a typo if you're wondering )



I've never seen this happen before, no matter what size textures i'm using... And these 8k rings worked no problem in pre6 and pre9!

I've seen other people post about similar problems though, so maybe i've missed something... (The standard saturn rings, and the ones for other planets work fine too btw)

My Specs:
Celestia 1.3.1pre"Callisto"
Win98 SE
128MB RAM (But more coming soon! )
NVIDIA GeForce4 MX440
Intel Pentium 4
All eye candy shows except ring shadows on planets!

[praesepe]

The same exactly happens to me, and I've tested them with other graphic cards (GeForce 4 Ti, and GeForce FX 5600). It only works when you resize down the ring texture...

[Bob Hegwood]

Jack,

I've experienced this problem with almost every ring texture I've downloaded. I figured that it was just my poor, underpowered machine. Take note though... I've been using a program called Pixia to get satisfactory results. You can get it at: http://www.ab.wakwak.com/~knight/.
Praesepe may be correct in saying that you need to re-size the texture. All I know for certain is that I've had to open and re-save these textures, paying particular attention to the transparency options while using Pixia to get satisfactory results.

Hope that helps.

Take care, Bob

[MB]

Jack,
This problem has already been treated in an other thread. I am also a CVS user. As far as I remember you MUST downgrade the rings to 4k, I had to do that, and then it works.
MB

[JackHiggins]

This problem has already been treated in an other thread

Hm yeah... I saw that, but forgot about it... Resizing the texture is no problem- but what i'm wondering is why do we have to have only 4k now, when 8k used to work fine...? I really liked those 8k rings...

[Darkmiss]

Exactly the same thing happend to me to Jack
Right after I Upgraded from Pre9 to pre11

I also had to resize them from 8k to 4k too.
I did ask why this happend from pre9 to pre11, but never got any answers.

[JackHiggins]

I did ask why this happend from pre9 to pre11, but never got any answers.

Well if this topic keeps getting bumped up, hopefully we will! Seems a bit weird to put a limit on the res of texture you can have- if your computer can handle it, higher res textures are ALWAYS better!!

*fluff post*

[JackHiggins]

*ahem*

Anyone know why a limit of 4k was put on the ring textures...?

[Darkmiss]

Hmmmm.....

[danielj]

Strange,in my case,only 2k texture of the rings works.I have the same bug with 4k texture.I only know that the maximum texture supported is 2048;but I don?t understand why this limit works for "transparent" like rings,but not for globes.
Again,my configuration :
Athlon XP 1800
256 MB RAM
Geforce 4 MX 440SE 64 MB
HD 60.0 GB Maxtor 7200 rpm
Windows XP
Detonator 45.23

[chris]

No limit was placed on the size of ring textures. Rather, Celestia does significant work to get around the hardware texture size limit for planets, but there's not a similar workaround for ring textures. This means that you're stuck with the maximum texture size allowed by your hardware--4096 for GeForce 3/4 Ti/FX and Radeon 8xxx/9xxx boards, 2048 for pretty much everything else that can run Celestia.

Celestia splits huge planet textures into multiple section that are each small enough for hardware to accommodate. This also requires splitting the planet's geometry, a technique which is straightforward for spheres but unreasonably difficult for general meshes. The geometry of rings can be divided into concentric rings for texture splitting, but I honestly don't feel it's worth the effort--is there really that much additional detail in the 8k rings texture?

--Chris

[JackHiggins]

Ok that makes sense- but that doesn't explain why I was able to view 8k textures on saturn's rings, in previous celestia versions (1.3.1pre6 for example) and it doesn't work now...? And I actually had more detailed saturn surface textures back in pre6, which you'd think might affect the texture loading on the rings...

It's not that i'm really bothered if I can't do anything about it- but those 8k saturn rings REALLY do look nice, and with cassini coming up in June an' all...

Would some type of virtual texture setup work?

An afterthought- since the saturn ring texture is 8k WIDE, but only a few pixels HIGH, this texture isn't that HUGE, probably the equivalent of less than a .5k if it was normal 2x4 size like proper planet textures...

[JackHiggins]

Chris? I don't mean to be annoying, but Darkmiss & myself would really like to know what the story is with the 8k textures working previously, and not now...?
Thanks

[Darkmiss]

Yeah I must admit I'm quite used to mucking around with Celestia now
and when i changed from pre6 to pre11, I got a shock.

after a few hours I got round to viewing Saturn, and I couldnt understand what was happening. (Solid Rings)

I was convinced I had done somthing wrong in the changeover proccess
And spent ages going over all I had done.
After hours of head banging, I tried resizing the texture, and it worked again. (to my amazment)

It was only a week earlyer that Jens Released these fine Rings to us.
and they was released as 8k, so it is obvious that 8k rings was working fine at the time.

It had me very confused for a while.

[danielj]

Yes,Saturn 8k ring texture works fine in Celestia 1.3.0,but not in Celestia 1.3.1 pre 11.I think this pre version still have some problems.

[chris]

8k textures were never really working . . . The OpenGL driver was
just scaling them down to the maximum size allowed by hardware--either 4k
or 2k. When I coded support for virtual textures, I added a check to
reject non-splittable textures (like rings, clouds, and 3DS textures) that
with a size that exceeds the hardware limit.

--Chris

[Darkmiss]

Ah thanks Chris, now I understand

Sorry if we came across like the Spanish Inquisition