Terrain Basics

[fREeCYCLE]

I've gotten enough familiarity with the node interface to have a few million bonehead questions and a couple reasonable ones.

1.  The terrain nodes appear to be one monolithic process.   i.e.  I'm not seeing how i can add a heightfield or second fractal to a scene without it being an inline part of the 'entire' terrain calculation.   Can I have two, multi-noded terrains which do not interact with each other?

2.  Can alphas be used as masks on imagemap heightfields which are blended into a powerfractal?

3.  In the event that I have a heightfield blended into a fractal terrain, how does one apply seperate shaders/textures to it without affecting the fractal?   No matter where I connect what... it seems to affect the whole.

4.  I flatly do not understand the principles behind 'edge blending by shader or imagemap'.   I keep trying different things, but never get what I might have expected (when I haven't bombed the app, which is about 40% of the time, almost undoubtedly from creating recursive structures)

Anyone up for a game of whack-a-noob? 

[Will]

I think the awnser to question two is yes they can that is if I understand it correctly. Don't know about the others though, sorry.

Regards,

Will

[mhaze]

Yes you can have more than one HF and texture, see attached

[Volker Harun]

Hi fREeCYCLE,

1. When in node-view, press the right mousebutton, to add an unconnected node.
You can build with theses seperate trees that can be connected (for example) with a merge-shader.
2. Yes. Just use an imagemap-shader for the density-shader input.
3. Look at (1.) You build a tree with one branch for the heightfield and one for the fractal-terrain. Shade them as you like. Before the planet-node set a merge-shader to connect them.
4. I do not have the software here installed - maybe somebody else might help you here.

Regards,
Volker Harun

Edit: mhaze, did it faster and better

[fREeCYCLE]

Thank you mhaze, that cleared up 1 and 3 quite nicely.   Knowing that merge shader exists as glue was the biggie I was missing.

A bit of clarification on 2: 
When creating an imagemap heightfield you have the option to check 'flatten area first' under displacement.  Does the 'flatten first' Only consider the square pixel dimensions of the imagemap, or could an alpha be used so that the flattened area takes it's shape?    Pure black may 'mask' the effect of an operation, but this is really just (Zero x Whatever) = Zero.    The 'flatten first' aparently pays not attention to black or white and attempts to flatten the square area of the imagemap regardless of content.


edit:  Great!   Thank you Volker, I will try these things shortly.   You beat me to this reply

Aparently, I was just going about it the wrong way.   Many thanks.

[Oshyan]

The "flatten first" flattens based on the area of the heightfield. It does not take into account alpha/masking/transparency. I'm not sure if there's a way to make it do so through that specific function but I'm sure there would be another way to accomplish it. You could in fact apply your terrain as an Image Map shader fed into a Displacement which might give you more control, or possibly use a Merge shader with your heightfield and the rest of your terrain for similar effect.

I'm not sure what you're referring to with "edge blending by shader or image map". Can you be more specific? I'm probably just having a moment of absent mindedness.

- Oshyan

[dhavalmistry]

Yes you can have more than one HF and texture, see attached

hey, would you mind sharing the result of that node network please...thanx...

[Njen]

3.  In the event that I have a heightfield blended into a fractal terrain, how does one apply seperate shaders/textures to it without affecting the fractal?   No matter where I connect what... it seems to affect the whole.

Here is one solution for that.
Cheers.

[Edit]: ops! I forgot the link!
http://forums.planetside.co.uk/index.php?topic=352.0

[mhaze]

hi dehavalmistry

Here's the pic WIP

[dhavalmistry]

NICE render mhaze

[old_blaggard]

Nice one .  Very cool.

[fREeCYCLE]

@Oshyan:  The 'blend by' I'm referring to is circled below.   Edge blending the heightfield into the fractal, I assume.

Any crashing I've experienced with these settings has been when randomly trying the Assign shader option.

[Oshyan]

The "Blend by" options are similar to using an alpha. In this case it allows you to blend by both heightfield and shader, since heightfield nodes are treated different than shader nodes. That's the only reason two options are offered in this case. For most nodes it's only "Blend by shader". I'm not sure what "edge blending" would be as far as being different from what I've described, but in any case that's the behavior. You would want to use normal color providing shaders such as Power Fractal, Distribution Shader, Surface layer, etc. here - if you are trying to use it with other more unusual nodes this may be causing problems; likewise if you are trying to connect it to existing nodes further up on the network you may be causing loops that are crashing.

- Oshyan