Generic Earth?

Started by Rob Allen, January 29, 2007, 06:58:38 PM

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Rob Allen

I was thinking of trying to see if it would be possible to use a fake stones shader to do distant trees.  The trick would be getting the distance shader to blend smoothly between the fake trees and real trees.  Alternatively, I was thinking about using tree sprites for distant trees, though this could be a problem from steep angles.  Essentially what we are talking about here is the creation of a LoD (Level of Detail) scheme, and there has been alot of research and development in this field within the video gaming industry.

old_blaggard

Interesting idea.  So you mean just applying a sort of conditional to the object: if object size > x, then render the object, otherwise use a similar-loooking surface layer.  We've already got conditional functions built into TG2, I guess all we need is something to detect the size of an object.
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Dark Fire

Quote from: Rob Allen on February 01, 2007, 01:24:43 AM
Essentially what we are talking about here is the creation of a LoD (Level of Detail) scheme, and there has been alot of research and development in this field within the video gaming industry.
An LoD scheme would be very useful for speeding up render times, and should be built into Terragen.

Will

yea I level of detail system would be nice but it would to be implmented in such a way that it would have the ablity to be toggeled on and off.

Regards,

Will
The world is round... so you have to use spherical projection.

§ardine

Quote from: Dark Fire on February 01, 2007, 02:46:41 PM
Quote from: Rob Allen on February 01, 2007, 01:24:43 AM
Essentially what we are talking about here is the creation of a LoD (Level of Detail) scheme, and there has been alot of research and development in this field within the video gaming industry.
An LoD scheme would be very useful for speeding up render times, and should be built into Terragen.

I believe Oshyan said something about this before.
Something like, LoD is already implemented to a very limited degree and perhaps it will be improved upon in the future...

Along the lines of what Rob Allen was saying though, It's fairly easy to create a simple tree sprite that would even look good from steep angles. The trick still would be in getting the switch between the two to be unnoticeable.  :-\

Oshyan

Just a note to say that rendering planetary shots is actually much faster in most cases than rendering from the ground. So even a highly detailed planet would probably render at decent speed from orbit. When you got down to the surface it might be a different story though.

- Oshyan

BPauba

#21
Quote from: Oshyan on February 01, 2007, 10:31:51 PM
Just a note to say that rendering planetary shots is actually much faster in most cases than rendering from the ground. So even a highly detailed planet would probably render at decent speed from orbit. When you got down to the surface it might be a different story though.

- Oshyan
Tis very good to know. I have noticed that a bit with some of my test renders. :D.

Oh, and I am interested in this idea. Especially the terrain aspect of it. I really have been doing alot of experimentation with the terrain nodes and functional nodes. I wish I had somebody that was as interested in the terrain nodes as I am, so I could collaberate with them in learning!

Rob Allen

Progress Report #1:  I've started on the Generic Earth Project.  I've implemented the ocean sphere, and it was looking good until I hit some kind of weird issue where now TG2 quits to desktop at some point during a full render.  I'm not sure what caused it, since about the only thing I've really changed since putting the ocean in is the position of the camera.  I managed to get a surface shot at about 700m altitude, an underwater shot, and a low-orbital shot, and now it crashes on every render.

I won't post the pics unless someone requests it.  I mean, really, it's just a big ball of water.  Once I get this issue worked out, I will start on the landmasses.

Will

excelent keep it up.

Regards,

Will
The world is round... so you have to use spherical projection.

buchvecny

lunar cell sucks... make your own planets its not that hard (:

Volker Harun

The first thing that came into my mind was building continents with thei climatic system.

1. There should be a climate effect concerning the latitude
2. The distance from coast should have another effect to the climate.
3. Thus a function could be built by latitude and distance from coast - (northpole=anywhere snow and ice; Europe could have snow above 1000m in the middle of the continent; getting nearer to equator will show snow only at 3000+ meters)
4. Different types of erosion depending on height and distance from coast (fluvial and rainerosion)
5. Inserting desert-zones by a fractal shader.

Just my 5 pence

Volker

Sethren

It does suck and i tried to contact the developer with some ideas that i had for the plug in. This was long before Terragen 2 as i was just making planets in Photoshop at the time. Seems like it is a 1 man operation and development is slower then molasses at Flaming Pear. Actually in my honest opinion making planets is hard, very hard. I mean when you are taking about good continent shapes and proper poles, isolating long mountain chains were they should be, creating different types of climates, if one wants realism for the sake of making earth-like worlds then there is a lot involved there. I have been studying geology for a long time now and i still can not get it down. Perhaps if there was a feature inside Terragen 2 were we can paint the shaders over the planet-size sphere then it would be easy to have specific elements of a planet's features were we would want them to be rather then second guessing for days on end using the current system of setting up shaders over an entire planet.

Rob Allen

Progress Report #2:  Getting the ocean trenches and seabed shaders just right took some time, but adding the continents on top of that took even longer.  Getting them all to work together to the proper effect was a bit of an excersize, but I eventually got it working.  I've got basically realistic shaped continents, though they are very simplistic at this stage.  I've also begun implementing the biome system.  Unfortunately, there does not seem to be any easy way to determine latitude, or if there is I haven't found it yet.  Therefore, the current biome system is very simplified.  Beaches are generated at coastlines, with forests being randomly scattered around the planet up to a treeline altitude.  Deserts and plains appear in randomized patches for the most part, and mountains occupy the higher altitudes with glaciers at the highest.  Therefore, the "poles" right now are at the center of the continents.  Not quite realistic, but it's still very much a work in progress.  I've just recently added a basic mountain generator, which creates denser, higher mountains in ares with higher base altitudes (hills with occasional outcroppings on coastlines, and craggy cliffs in the glaciers).

I'll get some pics from the render machine and post them here soon.

king_tiger_666

Quote from: Voulge on February 05, 2007, 05:30:40 PM
The first thing that came into my mind was building continents with thei climatic system.

1. There should be a climate effect concerning the latitude
2. The distance from coast should have another effect to the climate.
3. Thus a function could be built by latitude and distance from coast - (northpole=anywhere snow and ice; Europe could have snow above 1000m in the middle of the continent; getting nearer to equator will show snow only at 3000+ meters)
4. Different types of erosion depending on height and distance from coast (fluvial and rainerosion)
5. Inserting desert-zones by a fractal shader.

Just my 5 pence

Volker

good points... I like the part about different types of erosion. but i suspect this would need to be fairly lengthy which the various types of erosion.. one i would like to see if glacial erosion functions if that were possible......

also sethren... I can see where you come from with a geology background....
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Will

Great job rob! I can't wait to see how this al turns out.

Regards,
Will
The world is round... so you have to use spherical projection.