Global population shader

[krisc]

Hi, I am a beginner in using Terragen 3. I am trying to render a fairly large area and I am just wondering how can I populate, say a region/ zoomed out version of a general area with lush forests. I am working on a country level DEM data, and the final output would be, let's say Brazil showing lush green forests. I've imported objects in the terrain with two object population instance over 100,000 area, but somehow hogs much of my hardware resources. Is there another way on how to populate the  area with objects or texture globally?

I am working on a country level DEM data, and the final output would be, let's say Brazil showing a lush green forests. Looking forward to your replies. Thanks in advance!!

Kris

[AP]

How much RAM do you have because what you are attempting is dependent on a lot of RAM for one thing. 100,000 meters square?

[yossam]

Might be better doing it procedurally............

[Dune]

That is indeed demanding a lot of RAM. Very low poly trees might help, otherwise populate just the area near the camera and do the distance with procedural 'fake trees', i.e. green bumps in the terrain.

[AP]

Brazil for example is about 4,400 kilometers across at it's longest diameter. I have just enough RAM on my Computer to do maybe 30 kilometers square of a population with spacing of say 3 to 5 meters between each object. A fully grown tree for example would be in the low tens of millions in that scenario were as an area the size of the Amazon could be around 400 billion trees, perhaps even many more then estimated. It would be around 146 times more in size or there about.

If you are working with 100,000 meters square then that would be 100 kilometers square to compare the size of the areas.

[AP]

That is indeed demanding a lot of RAM. Very low poly trees might help, otherwise populate just the area near the camera and do the distance with procedural 'fake trees', i.e. green bumps in the terrain.

That could work well as long as the coloring matches the foreground into the background well enough.

[Hetzen]

Oshyan did a test render a while back where he populated a whole planet with trees. Not sure Ram is a problem. It's the objects ram requirements rather than the population's.

[AP]

Oshyan did a test render a while back where he populated a whole planet with trees. Not sure Ram is a problem. It's the objects ram requirements rather than the population's.

http://www.planetside.co.uk/forums/index.php/topic,6797.msg72087.html#msg72087

I though the larger the population size, the more RAM was needed?

[Oshyan]

Indeed, the more instances, the more RAM you need. But also the larger the object (file size/geometry count), the more RAM needed.

I would say that there is no way you would see individual trees from a distance necessary to view the country of Brazil! Or 100,000 square meters. Much better to use some kind of procedural displacement approach, maybe with a Perlin Billows noise function. But honestly at an orbital level you wouldn't even see the ~100m height of the forest canopy, just the color...

- Oshyan

[AP]

That is interesting to know about the object size.

[krisc]

Thanks for all your quick replies. I am running on 16 GB RAM  Xeon R Processor. I won't need to see each tree or grass, I would only want to see a terrain covered with vegetation just to give it some texture. Taking into consideration the RAM needed for this, is there a way to view the terrain in such a way that it is somewhat covered with trees or vegetation at the regional/country scale with minimal usage of objects? I was thinking if there is a texture function other than finding a satellite imagery and draping it on top of a DEM.

Thanks,

Kris

[Dune]

There's not a specific texture function, but you can build it using some 'treesized' billowed fractal, displaced to tree height, and colored with a variation of greens and browns. If you mask that where trees are, and make another texture with flatter grass colored ground, you can have grass and trees looking quite good at a distance.

[TheBadger]

didn't FrankB make a solution for this and post it some place around here? Pretty sure he did.

[cyphyr]

Unless you're going to see individual trees there is NO point at all in making a population that huge (aprox four hundred billion trees in the Amazon).
The only time this would be relevant is if you're animating down from space. And even then only at the lowers part of the animation and then only the area in camera view.
As Oshyan says try to make a forest texture and use this for displacement.