Celestia Forums

Anyone have any experience running Celestia 1.6.0 on an ATI Mobility Radeon HD 4670 graphics card under Windows 7 64-bit?

I'm getting strange artifacts in the textures, followed by lockups of Celestia. I updated the graphics card driver to the most current version from ATI (AMD), and the problems actually got a little worse.

Thanks!

Could you post a screenshot of the graphics issues?
I've had some as well, but they tend to only show up when I have too many things enabled (eclipse shadows + comet tails + ... etc).

Thanks "Hungry4info." I'll try to grab a screenshot when I get the chance. In the meantime I'll just say that, prior to my driver update, I would sometimes see flashing streaks in the background while travelling through space. Now, post driver update, I see a gridwork pattern of large, black, diamond-shaped artifacts in the textures of celestial bodies.

Perhaps something similar to this (if not colour, but shape)?

Our systems are similar, and I suspect our problems may be related.

Can you get the problems you are having to go away by disabling some of the graphics options?

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I'm using the Catalyst driver from the ATI/AMD Website.

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You might try selecting different Render paths to see if that helps.
Type a Ctrl-V several times.

OK, I just started Celestia, changed my render path to "Basic," did a "Go To" to Amalthea, and began slowly "right-click-dragging" my view of Amalthea. While "right-click-dragging," Celestia completely locked-up (stopped responding in Windows). My laptop's fan continued to run fast until I performed a "CTL-ALT-DEL/Task Manager/End Process."

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John: I tried your suggestions. In the ATI/AMD Catalyst Control Center, I turned off "4x auto," and changed all anti-aliasing settings to "allow the program to set it." Celestia still locks-up on me.

Actually I first used Celestia several years ago on an old (year 2000), slow Sony Vaio laptop (500MHz processor). Celestia ran great on it, albeit slowly. The monitor was only capable of 800x600 resolution, and the graphics were very limited - so I was really looking forward to getting back into using Celestia, and running it on this new, pumped-up laptop! I certainly hope that I can get it working! Thanks for your help so far!

Hungry4info: I haven't forgtten you! I haven't been able to "screen capture" the strange artifacts that I'm seeing because I haven't been able to get past the lock-ups in order to see them again! Your "screen capture" is only vaguely similar to what I am seeing. I'm seeing a gridwork pattern of large black diamond shaped artifacts in the textures. Thanks for your help so far as well!

Selden: Thank you for your help also!

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OK, thanks John. I wish I'd known more about these cards (ATI/AMD vs. Nvidia) and Open GL before I bought this laptop!

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John, is this something that I can configure?

You might try renaming the directories Celestia/textures/medres and Celestia/textures/hires to something else (e.g. append a NO to their names.) That way Celestia won't be able to find the higher resolution textures.

If you can get Celestia to start at all, you can select the menu item Render --> Texture Resolution --> Low
That will cause Celestia to ignore the contents of the medres and hires directories.

John's claim about higher resolution textures is somewhat obsolete. I have no problems viewing high resolution textures on my laptop, but it's a recent high-end business-class laptop with a 512MB Nvidia NVS 3100M graphics chipset.

I think I might have Celestia working now - but it's early yet! Before I explain, I have two questions:

1) My ATI Mobility Radeon HD 4670 graphics adapter has 1024 MB of SDRAM, so if graphics adapter memory is what imposes the restrictions on image resolution (Low; Medium; High), then I shouldn't have a problem here, and should be able to use High resolution - correct?

2) With my graphics adapter, Celestia gives me four choices of render paths (Basic; Multitexture; OpenGL vertex program; OpenGL 2.0). How do these different render paths differ (i.e. what do they mean)? And what is the order of them in terms of quality? - as I have them listed (which is the order in which Celestia listed them)?

OK, here's what I did:

Having more or less given up, I returned to the Catalyst Control Center and turned all of the anti-aliasing options back on (including the "4x auto" option that John mentioned). I later decided to give Celestion one more try with the only render path that I had not really tried (OpenGL vertex program). To really do a "stress test," I left anti-aliasing on (in Catalyst, and in Celestia - though I have since turned it off in Celestia under the assumption that "double anti-aliasing" is over-kill); I cranked up the resolution to "High;" and I set the render path to "OpenGL vertex program." So far, so good! But, as I said, it's early yet!

I should add that I finally saw the strange gridwork pattern of large black artifacts again (of which I was hoping to get a screenshot for Hungry4info). As I toggled through the render paths this time, they only appeared in the "OpenGL 2.0" render path! They are actually not diamond shaped (now that I see them again), but are a sort of spiked star shaped - and they flickered on and off in unison! I screen captured them while they were in the "flickered on" state - but the captured image does not show them!!!

Now that I have provided more detail, does any of this make sense to anyone?

I'm going to keep traveling around in Celestia before I'm going to really pronounce this problem solved. I'll keep you posted.

Once again, thank you Hungry4info, John, and Selden for your help.

OK, Celestia just locked-up again - but only after about 25 minutes of traveling around . Normally it would lock up only after a minute or so. I was "right-click-dragging" the Earth around - fairly close-up. So, now I'm trying it with the resolution backed down to "Medium." I visually can't see much difference between "Medium" resolution and "High" resolution anyway (though "Low" resolution looks horrible). So, if graphics adapter memory is indeed the problem, perhaps this will lessen the burden on it.

You could try this:
- set the antialias in the Catalyst panel as "application controlled" or similar description;
- open the "celestia.cfg" file (within the main Celestia's root) and browse the file toward the end. You will see an enter named "# AntialiasingSamples 2" (note the sharp before; the string is inactive);
- remove the sharp sign (uncomment out) and set "2" as value (no quotes); then save the file and restart Celestia.

The OpenGL render path is the best one; if your adapter allows such render, you must use that; whatever improvement and test for your issues, would have referred to it.

You might consider submitting a bug report to AMD. Sometimes vendors can be quite helpful in that regard. Intel was kind enough to point out a limitation in their chipsets which was easy to code around in Celestia.

It's not the graphics memory which limits the size of textures, but rather the design of the circuitry and associated firmware which draws the texture images onto 3D objects. Memory capacity would limit the total number of different textures being drawn on different objects and the total number of 3D objects. Very few games use extremely large surface texture images, so these kinds of bugs wouldn't be encountered very often.

Celestia doesn't include a lot of hires textures, which is why switching to Medres wouldn't make much visual difference for most objects. Celestia's high resolution setting tells it to use whatever textures are in the textures/hires folder. If there is not a texture there which has the appropriate name, it'll use whatever is in the folder textures/medres. Traditionally, the textures in the medres folder are limited to 1024x512 pixels, while those in the hires folder are larger. Some extremely high resolution surface texture images are available on the Celestia Motherlode. The highest resolution surface texture Addons use "virtual textures" which contain images which have been broken into smaller tiles. They might actually work well with your graphics hardware, since most use 1K or smaller tiles. Celestia does not come with any virtual textures included.

The various Render Paths select different sets of drawing functionality which were added to Celestia as additional capability became available in newer OpenGL standards.

Basic: OpenGL 1.1
Multitexture: OpenGL 1.2
Vertex shading: OpenGL 1.4
OpenGL2: OpenGL 2.0

In other words, it seems that, in addition to the texture size issue, there may be some limitations (bugs) in ATI's implementation of OpenGL 2.0 or 1.4 for the graphics chipset in your computer. If the problem is with a particular OpenGL function (or a small number of them), you can tell Celestia not to use that particular function or functions. Down at the bottom of celestia.cfg is the "IgnoreGLExtensions" option. Unfortunately, it may be a bit tedious trying to figure out which ones are causing problems.

I hope this helps a little.