Types of Landform and Other Geophyiscal Phenomena not Possible in TG2

Started by Cyber-Angel, November 29, 2008, 11:32:22 PM

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Cyber-Angel

Could one of the developers please tell me what kind of landforms and other such geophysical phenomena that are not physically possible to replicate at this time using the available noise types and other current technology available in TG2 at this time and for the foreseeable future.

I understand that TG2 is an extremely flexible peace of software, all software has limits imposed by its technology; these limitations are inherent to a greater or lesser degree depending on the software in question. The reason I ask is I wish to know which geophysical phenomena to avoid for contest themes as there is no useful purpose in setting up a contest, that is not physically possible to do in software.

Regards to you.

Cyber-Angel ;D               

PG

Is there any particular landform you were thinking of? Listing every form of land structures that TG2 isn't capable of may be a bit difficult, even for the developers ;D. I'm pretty sure that TG2s real limitation is that it uses noise in a fixed dimension fashion, which makes arches and things quite difficult. The power fractal is applied horizontally and for every displacement you have laterally you have another noise function applied vertically and then to complete the arch you have to invert a new noise function horizontally which looks awful. We need a terrain manipulation tool that can be easily switched between 3 (or more) dimensions. Also twisting terrain in a spherical or cylindrical sense is ni-on impossible. You can only manipulate in straight lines but using massive amounts of very small adjacent displacements you can give the effect of terrain twisting round a point. I think those are the two main limitations, the lack of 3d manipulation and manipulation off the perpendicular beaten track. If you have anything specific that you were thinking of then I'm sure Matt, Oshyan or Jo would be able to tell you whether that's within the realms of possibility.
Figured out how to do clicky signatures

Confusoid

Even though i rarely touch TG2 i will weigh in because i love geology.   ;D

Lacking:
River Networks w deltas.
Alluvial Fans.
Deep Fluvial Erosions.
High Sediment Flows.
Inverted Erosions.
Fluvial Terracing.
Thermal Erosion.
Glacial Erosion.
Glaciers.
Physically Correct Long Flow Erosion.

i may be missing some other details and i ain't even going to talk about ocean waves which is a joke at the moment.

dandelO

Ocean waves are not a joke, Terragen is very versatile and I think I could get the most realistic looking waves from it(as opposed tu Vue/Carrara/insert 3D app' of choice) using displacements.
The beauty of TG is that you can specify exactly where everything should be with the multitude of tools that come straight 'out of the box'. There is no 'random' in TG(except the initial 'random seed' of a given fractal. ;)), tell it, correctly, or more realistic, 'logicaly', to put a displacement on your screen and it will, to within a range of millimetres.

The downside of this, of course, is that you need to rely on your own own calculations, just setting a water shader to a surface and typing in a wave scale of '30m', for example, isn't going to cut it.

Some, if not all, of the effects you list could be achieved with the existing heightfield operators, shaders and functions.

Logical and lateral thinking are the best tools to use in any TG scene, in my opinion. There's no quick-fix, except a lucky one. ;)

jo

Hi,

All of these things are possible one way or another. Ok we might not have physically correct automatic generation of these yet, but if you're a bit creative then I don't see a problem. Taking confusoid's examples:

River Networks w deltas - create masks/heightfields in another app, import, add extra detail with fractals etc.

Alluvial Fans - shallow cone shaped function with centre at point where deposition starts, add extra detail with fractals etc.

Deep Fluvial Erosions - plenty of third party apps, GeoControl, World Machine etc. can generate flow maps. TG2 will have built in facilities eventuall, I'm sure.

High Sediment Flows - like slips and such? Same as above. Or make your river look muddy or something...

Inverted Erosions - take/paint a flow pattern, invert it

Fluvial Terracing - Posterising displacement of an existing terrain using functions

Glacial Erosion - depends what you mean, but you can probably make glacial cut valley profiles using functions to modify displacement. Use the painted shader to create moraine, add fake stones/extra fractal detail etc.

Glaciers - doesn't seem like the most difficult thing to model

All of these sound like things which would make for good competition subjects because they can be done and they'd be a challenge. No doubt focussing on creating these things would be a great learning exercise.

Regards,

Jo

Confusoid

I'd like to see river networks inside TG2 though.   :)  It will have to wait.

If Alluvial Fans can be done that way then great. Could be something to test out.

Slips, i think so.  :)

Glacial Erosion like Alaska or older types like how Yosemite was carved.



Confusoid


jo