Heightfield Erosion??

Started by buzzzzz, January 18, 2007, 11:00:30 AM

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buzzzzz

Hey Gang!

I can't seem to find any Documentation on Erosion. First, I noticed if I erode my height field, save and exit TG. Then later when I start TG, open my tgd the Erosion node starts it's process all over again. Can anyone tell me if this normal and will it put everything back to my last saved tgd, or will the Height field be eroded even more which I may or may not want?  Or should I erode and then disable the erosion node when I get the effect I'm after? Second, how the hell can I get channeled erosion? Does anyone know of a Tutorial on Erosion?

Your Help is Appreciated,
Jay

Will

Hey, I don't think the built in heightfield erosion is fully implmented yet and there are still some bugs to work out, you could try running the hightfield though world builder or a simlar program to get better resaults. I realize this is not really all that helpful but its the best I know about it right now.

Regards,

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

buzzzzz

Quote from: Will on January 18, 2007, 02:51:20 PM
Hey, I don't think the built in heightfield erosion is fully implmented yet and there are still some bugs to work out, you could try running the hightfield though world builder or a simlar program to get better results. I realize this is not really all that helpful but its the best I know about it right now.

Regards,

Will

Thanks Will, was starting to feel ignored. 20 people looked but nobody responded until you did. LOL 

I have imported some of my WM Terrains but they seem to lose detail once imported ? Which sucks!  I may also try erosion with a distribution shader.  That's Ok I'll figure it out. Was thinking I would get a response from one of the staff that was here a little while ago, but I guess I thought wrong.

Thanks Again Will!
Jay

Oshyan

Sorry for the delay in replying Buzzzzz, we've all been a  bit busy with various things. I'll be going through all the messages over the next few days and replying.

In any case the built-in erosion is definitely an in-progress feature. I would say all the heightfield modifying nodes are, in fact, and I tend not to use them. You're generally better off creating any heightfield terrains in a separate app as you'll get more control and stability. TG2 doesn't yet offer many particularly unique heightfield functions either. All this will be improved for the final release, of course.

But if you do want to use the heightfield effects one major thing to keep in mind is that both the built-in heightfields and certain effects (such as erosion or river) must be *re-generated every time you close and re-load the file*, unless you save the result of the heightfield after generating/editing with Right-click and Save Terrain As (on the heightfield node). This is because TG2 saves only the descriptor files (.tgd) which are very small but do not contain the actual heightfield raster (pixel) data which would be much larger. Saving the results of your heightfield editing can be done as above and then simply replace your heightfield generation and edit nodes with a heightfield load.

Imported terrains, from WM or otherwise, certainly shouldn't be losing detail. In fact TG2 adds procedural detail to heightfields by default. You may want to turn this off if your heightfield isn't looking the way you want it to. Go to your Heightfield Shader on the Fractal Detail tab and uncheck Add Fractal Detail. However it's not likely this is causing your problem. One thing I know are an issue with WM terrains in particular are height values and scaling. WM has had an issue even with TG 0.9 and outputting incorrect heights to the .ter file. You can use a Heightfield Adjust Vertical node in TG2 to get the correct scale or just adjust it in TG 0.9 and re-save with correct values.

If you're still having problems with imported heightfields after trying these things it would help to post some example images - perhaps one of the heightfield in WM or TG 0.9 (the way you expect it to look) and then one in TG2, pointing out what's wrong.

- Oshyan

buzzzzz

No problem Oshyan, you know me "Mr Patience" here and thanks very very much for explaining the erosion issue at the moment. Good Idea about rendering some samples. I'll work on it after this render finishes in a couple of days. He he!  BTW, I am having loads of fun with this thing, not many crashes lately either. Thanks for the Help Oshyan!

Jay

Oshyan

Glad to be of help and most definitely glad to hear you're having fun. You've been one of my favorite TG artists for quite a while now and I'm looking forward to seeing what you're able to do as you get more familiar with the vastly expanded possibilities of TG2. :)

- Oshyan