planetary rendering

curantil · Post by **curantil** » Thu Jun 02, 2005 12:04 am

Some time ago I dropped somewhere on this forum that I was working on planetary rendering. Now I have something to show.

It isn't finished, think of it as an 0.1 release. For the moment it only works on Ogre 0.15.2 (Hastur) But I will continue working on it and upgrade it to Ogre 1.0. (But now I have examens, so it will be on hold)

The source and some demo-movies are found on:
http://sites.google.com/site/curantil/p ... enemanager [edited the url]
I have put a some help on that site.

Feel free to test it and give comments.

Post by **jacmoe** » Thu Jun 02, 2005 12:15 am

Nice to hear!

You should post a screenie (ASAP) - It is a requirement of this showcase section.

curantil · Post by **curantil** » Thu Jun 02, 2005 12:22 am

Oops, here they are then

alphageek · Post by **alphageek** » Thu Jun 02, 2005 3:04 am

Veeery interesting. What techniques are you using?

monster · Post by **monster** » Thu Jun 02, 2005 3:08 am

That's really cool.

My only suggestion would be if you could add a "detail" texture for when you're close up, like in the second and third shots. It would stop it looking so unnaturally smooth when you're near the ground.

The first and last shots look grrreat though!

Post by **Kencho** » Thu Jun 02, 2005 8:47 am

Curantil: Mars and Ceres?

Nice shots

curantil · Post by **curantil** » Thu Jun 02, 2005 9:14 am

I am planning to do detail-textures yes.

Kencho:
No, the small one is Phobos, a moon of mars. The canyon on Mars is Valles Marineris

The technique is based on Geometry Clipmaps that are wrapped on a sphere like a cubemap.

Here are some more screenshots of an approach of a crater on mars (I hope that it doens't make the thread to big to load):

Post by **jacmoe** » Thu Jun 02, 2005 9:28 am

Amazing!

Are you doing Celestia III ?

Post by **DWORD** » Thu Jun 02, 2005 10:31 am

Nice shots! And nice to see you succeeded.

Post by **Kencho** » Thu Jun 02, 2005 10:39 am

Right, it's not ceres

I noticed it a few minutes after posting that...

Really good images there

curantil · Post by **curantil** » Thu Jun 02, 2005 3:30 pm

I have added some demos for windows to the site:
http://sites.google.com/site/curantil/p ... enemanager

They are without data-sets to make it smaller to download. So you also need to download the datasets. The configfiles are setup to preprocess the data, so the loading will take longer. After preprocessing the dataset you can alter the configfile though so it doesn't preprocess every run.

Post by **DWORD** » Thu Jun 02, 2005 3:41 pm

I'm missing the STLPORT_VC646.DLL. Can you add it to the archive?

curantil · Post by **curantil** » Thu Jun 02, 2005 4:07 pm

Ok, I'm currently uploading the new archive.

I have the dll for those who downloaded it already: http://sites.google.com/site/curantil/p ... enemanager

Hope it works now.

skullfire · Post by **skullfire** » Fri Jun 03, 2005 6:20 am

Dude this looks so awesome... love the uniqueness of the technique, and love the screens too(noting the high framerate considering the, what seems to be, a high polycount overall).

curantil · Post by **curantil** » Fri Jun 03, 2005 9:47 am

To be honest, the framerate in these screenshots are misleading. These are taken when the camera is not moving. In that case the algoritm doesn't have to do anything. The actual framerates should be around 20-60fps.

bleeder · Post by **bleeder** » Fri Jun 03, 2005 1:13 pm

Looking good!

Though I must agree with monster, adding detail textures would be good idea, but besides that, it's cool - good job!

Sputnick · Post by **Sputnick** » Sun Jun 05, 2005 7:56 pm

Very nice demos.
The transitions are impressively smooth.
Congratulations !!

If you haven't done it already, you should also have a look at Hugges Hoppe's papers, especially about progressive meshes:
http://research.microsoft.com/~hoppe/

- Sput

PeterNewman · Post by **PeterNewman** » Wed Jun 08, 2005 3:59 am

I remember watching the movie on the persons site of the geometry clip maps, and went "I need to get this to work". So glad to see that some-one was able to do it!

ahmedali · Post by **ahmedali** » Wed Jun 08, 2005 9:52 am

@curantil
Im not sure how to ask the question. What is the maximum limit of detail when we have just landed on the moon/planet. Can it show detail per meter?

curantil · Post by **curantil** » Wed Jun 08, 2005 10:27 am

Well, for the moment it isn't very optimized, so the detail visible at once is limited to triangles with the longest side of approximatly 12 pixels. (That is the lowerbound)

For the size of the world. There is virualy no limit but the precision of your graphics-card. It loads the geometry dynamicly and refines it if the "real" map isn't detailed enough. On the most detailed of these pictures I guess the triangle-resolution of the most detailed area's is about 2km.

The maxima you can get (for mars, diameter 6000km) are details of 100m on ATI (24bit) and 1m on nvidia (32bit) on older nvidia you can only get to 5km resolution (16bit). If your planet is smaller the resolution can be better ofcourse, because the resolution is relative to the radius of the planet.

Maybe I can later try to get a better resolution for that by translating the geometry so the viewpoint is always near the origin of the world. But I'm shure if that is going to work.

phenix · Post by **phenix** » Mon Jun 13, 2005 9:44 am

cool!
By the way, where can I find the bits of precision of video cards?
I tried to find the precision of my geforce mx but I couldn't, but probably it is quite low.

curantil · Post by **curantil** » Tue Jun 14, 2005 4:10 pm

@phenix : I have no idea where to find the precision of a specific card. Maybe on the manufacturers site or in the manual of the card?

I have updated the plugin for Ogre 1.0 and implemented detail texture. The code is uploaded to the site (first post) together with the explenation how to build it. If you need any help feel free to ask.

The problem is, the planet is very big. So using 1 detailtexture gives not very much extra detail, or if you shrink it a lot, the repetitive pattern becomes visible. I guess I better use more detail-layers. Should I recursivly detail the layers with the same texture? Or should I use for every layer an other texture?

I'll post some screenshots soon

jtarbox · Post by **jtarbox** » Thu Jun 16, 2005 2:31 pm

Been looking at stuff like this for a while and noticed your post. How would this scenemanager handle other objects at the same time..

ex, how well would this handle a typical space scene with starfield/nebula backdrop, several spacecraft meshes w/ associated billboards and particle effects, and even several planets in view at the same time? I was looking at octree my self as it's better suited for such an open scene, but the planet rendering is definately a something I'd desire.

also, in the moon movie the planet didn't show up till (it looked like) you moved towards it.. was that just a demo application limitation or does the scenemanager have problems in displaying planets at farther distances?

-jtarbox

jtarbox · Post by **jtarbox** » Thu Jun 16, 2005 2:37 pm

and the other question I had was in the movies there is a lot of altering of the terrain at close range. So much that it's very visible to the observer. Is there options to prevent that morphing? (aka, increase the range of the higher detail resolution...)

-jtarbox

curantil · Post by **curantil** » Thu Jun 16, 2005 3:14 pm

For the moment is only can handle a planet. I haven't tried adding other models yet.

The black in the beginning of the moon movie is just because the ogre-window didn't have focus. So it didn't render. It is not a limitation of the algorithm. For far distances the planet should better be replaced by a billboard. But that is not implemented yet.

You can increase the range for the higher-detail resoulition, but the implementation isn't optimal enough for keeping the movement smooth. (At least for my machine)
You can also increase the size of the transition region. But that also takes longer to calculate and you'd lose more detail.