## basic terrain modifications, like 'chop off the peaks', eludes me

Started by shadowphile, September 13, 2009, 08:24:50 pm

#### RichTwo

##### September 18, 2009, 12:20:57 pm #30
I read a lot of tutorials, seen the screenshots  and they may as well be in ancient Etruscan for all I understand.  To truly grasp T2, one needs a fairly comprehensive knowledge of mathmatical functions.  Something I shamefully lack.  Heck, I have trouble keeping my bank account from tanking...

What Matt has shown is simple and elegant, and  I'd sure like to see more of this!  Thanks to all who added something here!
You don't need a weatherman to know which way the wind blows...

##### September 18, 2009, 09:23:11 pm #31
bravo Matt!  That is the exact kind of information I was looking for and clarifies a lot.  Subtracting the altitude from itself to recreate just the displacment, using my example, is something I kept feeling I would need to do but didn't know how.  The short of is that there is no way to DIRECTLY specify a terrain, it must always be shaped to act as a DISPLACEMENT from the input terrain.
I can run quite a ways with just this info, thanks for the breakthrough.  Its appears others were hungry for this level of understanding as well.

#### efflux

##### February 24, 2012, 04:12:59 pm #32 Last Edit: February 24, 2012, 04:20:49 pm by efflux
Quote from: Matt on September 17, 2009, 09:08:39 pm
This is obviously something that I want to make easier and more intuitive. The setup I suggested is pretty simple and allows almost any kind of function-based modification of altitudes, but you have to think along particular lines to come up with the idea in the first place. So my question to anybody reading this is: how would like you like to see the interface work for general modifications of terrains by altitude? It needs to allow general function modifications like the above, in addition to any other easier methods which might be included. While a shader that allows you to perform basic modifications or to draw an altitude profile curve would be great (and may come in future versions), we also need a more intuitive way to utilise function nodes like the setup I showed above, but without the counter-intuitive node setup.

(I hope you don't mind me hijacking your thread, shadowphile. I hope you find the example I posted useful.)

Matt

Just found this old thread. I agree with njeneb.

A curve graph with maximum and minimum inputs and outputs. Then this can simply be used to manipulate whatever ranges you want whether it's altitude or the fractal output to colour or whatever. It becomes THE most powerful component in TG2. This may not be easy to add to TG2 but it's the ultimate solution. We need to get into the concepts of what we are doing so that it's not about "altitudes" or whatever but about - you change these values and ranges to get this output shape. This way TG2 remains open ended. If we say have something that can sculpt altitude profiles then what if we want to sculpt something else via some sort of curve? It all ends up more confusing rather than understanding the actual basics of the data and how that shapes the forms.

#### efflux

##### February 24, 2012, 04:36:56 pm #33 Last Edit: February 24, 2012, 04:39:35 pm by efflux
For example, at the moment it is possible to pretty much sculpt the terrain profile fairly accurately but by joining together a mass of maths functions and in particular, the smooth step node. I currently have a big set up like this to sculpt terrain profile but it could all be achieved with a single graph.

Yes, I know a curve graph that can handle everything is probably not a simple addition but thinking along any other lines is pointless.

#### jo

##### February 24, 2012, 05:04:51 pm #34
Hi efflux,

TG2 will definitely have a curve graph in the future.

Regards,

Jo

#### efflux

##### February 24, 2012, 05:14:33 pm #35
OK, thanks Jo.

I just read Matt's response on here although it was a while ago. He seemed to be suggesting some kind of shader type thing that might just do terrain profiles which kind of worried me.

#### Matt

##### February 24, 2012, 06:38:04 pm #36
Quote from: efflux on February 24, 2012, 05:14:33 pm
OK, thanks Jo.

I just read Matt's response on here although it was a while ago. He seemed to be suggesting some kind of shader type thing that might just do terrain profiles which kind of worried me.

When we implement this we'll start with a function node that applies an editable curve to its input. We're well aware that it's useful for much more than direct manipulation of terrains. There might also be a displacement shader that applies a curve to the displacement or altitude on a surface, but we'd almost certainly give you the function building block first.

Matt
Just because milk is white doesn't mean that clouds are made of milk.