Author Topic: The sky isnt being rendered well in preview mode  (Read 11016 times)

Offline wonderbean

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The sky isnt being rendered well in preview mode
« on: November 18, 2007, 10:14:56 PM »
I just downloaded tg2 and in preview mode the sky is not rendering well.  It is a collection of squares at different angles.  Some look like sky but others are just gray... and they stay that way.


Offline rcallicotte

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Re: The sky isnt being rendered well in preview mode
« Reply #1 on: November 18, 2007, 11:01:20 PM »
The default atmosphere might be a bit thick for you then.  You can adjust it.

The preview mode is just that, though, and (as I can see from your captured image here) when you are higher up and looking across the distances, you will find that your distant land mass melds more readily with the sky.  This is as it is in real life.
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Offline Cyber-Angel

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Re: The sky isnt being rendered well in preview mode
« Reply #2 on: November 18, 2007, 11:57:37 PM »
I have the same problem which I think is related to the ATI Graphics Card I have, I cannot see any thing else it could be, then again I might be wrong and it could be some thing else after all this software is still a work in progress.

Its like the sky is all broken up in the 3D Preview instead of been smooth, I am just wondering weather if a graphics card is bellow a certain threshold for on board memory weather that has implication's for the way the Open GL Preview will display, as when you render the scene every thing is how it should be.

It could just be some thing to do with the way that TG2 handles Open GL some thing to look into.

Regards to you.

Cyber-Angel             

Offline Oshyan

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Re: The sky isnt being rendered well in preview mode
« Reply #3 on: November 19, 2007, 02:40:38 AM »
The preview is generally supposed to render completely and not show those gray areas. When it doesn't it generally seems to be related to graphics card issues. Older or less capable cards are more likely to have problems. You can try updating your graphics card drivers, but some recent ATI drivers have actually been *worse* with many OpenGL applications (not just TG2), so that may not work that well. I'm not sure whether they've fixed those issues yet. If you have a newer card you can probably count on a future graphics driver or TG2 update making it work better, but for an older card you may just have to work with it that way unfortunately.

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Offline rcallicotte

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Re: The sky isnt being rendered well in preview mode
« Reply #4 on: November 19, 2007, 04:32:18 PM »
I guess I didn't realize how off my graphics card is.
So this is Disney World.  Can we live here?

Offline bigben

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Re: The sky isnt being rendered well in preview mode
« Reply #5 on: November 20, 2007, 02:43:47 AM »
Defnitely graphics card/driver-related... and newer is not necessarily better. My oldest system renders the atmosphere  preview the best.. Must try some of the newer machines at work  ;)

Offline Matt

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Re: The sky isnt being rendered well in preview mode
« Reply #6 on: November 20, 2007, 11:57:47 PM »
This tends to happen with different levels of severity on different graphics cards/drivers, but there is a workaround. The clipping planes used by Terragen's OpenGL display can be adjusted using the '[' and ']' keys on your keyboard. After pressing ']' key a few times the sky should render correctly, but this also adjusts the near clipping plane so you may find that the foreground cuts off if you get too close.

Matt
 
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Offline Cyber-Angel

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Re: The sky isnt being rendered well in preview mode
« Reply #7 on: November 21, 2007, 01:54:09 AM »
Thanks Matt,


I do have a question, would it be possible (Theoretically Specking) to have some kind of automatic process that looks for this issue and corrects it before it is apparent to the user with the work around you suggest been there as a manual backup should the automatic process not work in all situations?

Regards to you.

Cyber-Angel       

Offline wonderbean

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Re: The sky isnt being rendered well in preview mode
« Reply #8 on: November 21, 2007, 11:14:09 PM »
Thanks for all the input. 

Is this a problem with Open GL?  Does terragen 2 support directx?

Offline Oshyan

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Re: The sky isnt being rendered well in preview mode
« Reply #9 on: November 21, 2007, 11:19:39 PM »
It's an issue with the way TG2 interacts with the OpenGL implementation in your graphics card or driver. Technically it's a limitation on the graphics card side but, as Matt mentioned, there are ways of potentially working around it. It mostly has to do with the large range of scale TG2 works on.

TG2 doesn't support DirectX and is not likely to do so any time soon because it is a cross-platform application (Mac and PC) and DirectX is not available on operating systems besides Windows. Given the availability of a cross-platform graphics solution like OpenGL it would be a bit of a waste to dedicate effort to a proprietary single platform solution that only covers part of our product range.

- Oshyan

Offline Matt

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Re: The sky isnt being rendered well in preview mode
« Reply #10 on: November 22, 2007, 12:56:52 PM »
I do have a question, would it be possible (Theoretically Specking) to have some kind of automatic process that looks for this issue and corrects it before it is apparent to the user with the work around you suggest been there as a manual backup should the automatic process not work in all situations?

Perhaps. I have thought about adjusting the clipping planes according to the closest object/surface to the camera. If I do that, the sky would still disappear whenever there is an object/surface close to the camera. It can make it so that the far clipping plane stays far enough to always capture the sky, but then there can be other problems with the depth buffer.

Matt
Just because milk is white doesn't mean that clouds are made of milk.

Offline Cyber-Angel

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Re: The sky isnt being rendered well in preview mode
« Reply #11 on: November 22, 2007, 02:14:16 PM »
Matt,

I am sure in time a solution to this issue can be found, which should also fix the camera ending up inside the terrain issue unless it is planed to have collision detection (Found in flight simulation games to prevent a players aircraft from flying though objects such as maintains) I look froward to seeing what you come up with.

Maybe a deterministic solution could be used so that the view frustum is linked to the clipping planes or some thing, unless there is a reason not to.

Cyber-Angel         

Offline Matt

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Re: The sky isnt being rendered well in preview mode
« Reply #12 on: November 22, 2007, 03:22:33 PM »
Hi CA,

Preventing the camera from going beneath the terrain is a completely separate issue. The OpenGL drawing problems come from limitations in the video card or drivers and the solutions involve changing the way things are drawn.

Not sure what you mean about linking the view frustum to the clipping planes. I have to choose clipping planes that capture as much of the scene as possible without making them so far apart that the video card can't render it properly. Another possibility is to not draw the background sphere so far away, but I'd have to make the renderer intelligent enough to know when it can start moving polygons around and when it needs to leave them where they are for proper depth occlusion. If all video cards had better depth buffer resolution I wouldn't even have to think about doing something as complex as that...

Matt
« Last Edit: November 22, 2007, 03:26:36 PM by Matt »
Just because milk is white doesn't mean that clouds are made of milk.

Offline Cyber-Angel

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Re: The sky isnt being rendered well in preview mode
« Reply #13 on: November 22, 2007, 11:53:40 PM »
Another idea is if the renderer new where the viewer (Called Render Camera) was in 3D space and could call (I think thats the term) information about camera position relative to the horizon (The renderer could interrogate the Render Camera Dialog for information on current position and rotation of the camera: ) plus current Field of View information (Also called from the Render Camera Dialog), the last thing the render (Or maybe the first) looks at is the current resolution 2000 X 3000 say, these three peaces of information tell the renderer how much sky can be seen by the observer and where it is in 3D space.

Then you'd take that information and look to see the current sky state in the 3d preview and look for gaps caused by the clipping plane issue and then use the method you'd described.

Just some ideas that came to me last night (Australian Time).

I hope these things I describe would not be nightmares, only trying to help  :)

Regards to you.

Cyber-Angel     

Offline Matt

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Re: The sky isnt being rendered well in preview mode
« Reply #14 on: November 24, 2007, 12:52:42 PM »
Hi CA,

Yes, that's the easy bit ;)  I can do that. As I said, the problem is in doing that without making the foreground disappear. The video card capabilities make it impossible to render such a large range of distances without artifacts. I make the user choose where the clipping planes are because I don't know whether you want to see the sky or the foreground in such situations.

Matt
Just because milk is white doesn't mean that clouds are made of milk.