Images as sources for terrain generation...

Started by Gkon, December 23, 2006, 07:50:27 pm

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Gkon

Is this possible with TG2?
Perhaps I'm not looking in the right place.
It would also be great if at a later date TG2 could generate
terrains seperately to populate a scene.
Much like Vue Infinite.

calyxa

terrain tab, add terrain button, choose the 'heightfield (load file)' option, then in the file select dialog, there should be a drop-down menu to limit the file selection to .ter files -- on this drop-down, you can have it limit to .bmp files, or a few other choices.

I haven't tried this yet, but it looks pretty straight forward.

Oshyan

You can use an image as a blend shader any terrain generator. If that doesn't accomplish what you're aiming for, perhaps you can explain in greater detail?

In the future you should be able to disable terrains (and other things) from being rendered while still allowing them to be used for controlling populations, etc.

- Oshyan

cajomi

BlendShader?
I only have found a blending for the border, there is no blend shader in TG2.

But to load a bmp tga or ter file as heightfield is quit simple, do it as calyxa wrote. I used this and works fine.
Developer of GeoControl

Oshyan

See attached for Blend shader inputs at the bottom of a Heightfield Shader.

- Oshyan

cajomi

I am speaking of clearness in the words, that are used:
The shaders which are available are shown in the menus, where you will not find a "Blendshader".
You are speaking of a shader, which you use for "Blending". I think, it is important  to name the things correct, most, if it is a complex software.
So far I have found:
You can use in the heightfield generate panel (below the heightfield shader) a tab called "Use shader", there you can use as input a heightfield shader, where you can load a ter file.
In the heightfield shader panel, you have at the button a option: Blend by heightfield, where also a heightfield can be loaded. This is of course not a "Blendshader" but a blending with a shader, where the shader never can be a "Blendshader".

At all I have found three possibilities of getting a heightfield into TG2. All with the same result: The heightfield is not applied to the planet object, but to the position in space, where the projection of the heightfield meets the planet. The heightfield does not follow the planet, but is set as a seperated object onto it and then blended. Good by Mars rendering???
Developer of GeoControl

Gkon

Thanks, calyxa. And everyone else for your comments.
My specific aim was to create a terrain that was a combination
of procedural (power fractal) and bitmap (greyscale for elevation).
I haven't yet delved into blendshaders and so I'm a bit behind perhaps.

calyxa

I'm also still confused about 'blend with shader' - I read in one place that it acts as a mask.

coming from MojoWorld, where there *is* a blend node, I find the terminology confusing as well.  the MojoWorld blend node takes 5 inputs - and I'll digress for another moment - nodes in Terragen seem to differentiate between inputs and parameters... in MojoWorld, a node will have as many 'spigots' on the top as parameters in the parameter editor screen.  if a parameter can't accept another node as input, it's only an outline.  but in Terragen, I haven't yet made any sense between what's a parameter that can be driven by another node and what's just a value that can be set - and there's often a 'spigot' on top of a node named 'input' which has no corresponding field in the parameter editor.

anyway, the way a blend node works in MojoWorld is you've got an input for the "blend value" - this can be any function, or constant value.  it defaults to 0.5, which makes a 50/50 blend, assuming none of the other parameters have been changed.... then there are two inputs to define the test range -- the "blend range low" and "blend range high".  these default to 0 and 1, respectively (which is why the 0.5 creates a 50/50 blend by default).  the last two parameters are "the value to output if the blend test is off the low end of the range" and "the value to output if the blend is off the high end of the range" - and in the case where the blend value is between the range specified, it'll actually blend the values (weighted average).

but here in Terragen, there's this "blend by shader" or "blend by heightfield" and while I saw that this is supposed to "act like a mask" I'm totally unclear as to what I get in the places that are "exposed" by the mask, and what I get in places that are "covered" by the mask, and indeed, what "values" from this "blend by shader" mean "expose" and which mean "cover"....

back to the particular topic at hand - I did sucessfully add a heightfield from image to a world using the steps I listed above, and it worked just fine.  in a separate test, I tried to "use a blend by heightfield," as suggested above, I did not get that to work.