[leveller] Re: Image overlay utility
- From: "Carl Lingard" <lingardc@xxxxxxxxxxxxx>
- To: <leveller@xxxxxxxxxxxxx>
- Date: Sun, 16 Oct 2011 16:57:03 +0100
I'm comfortable with manually doing things to a point. I use Leveller for the
painting tools and the 3D view. Yes, it's kinda like the music recording
analogy, where you'll spend hours painstakingly digitally correcting a
recording, rather than just record it again. I think you learn with experience
where the tipping point comes between procedurals and painterly approach. I
think World Machine's vector tools are excellent- the controllable fractal
breakup applied to the vector shapes works really well, but they're limited
without procedural vector generation.
Building at any great scale just can't be done. I've compared the results in a
planetary renderer, and procedural terrain just looks really poor frankly.
Small areas can be done really well, but anything beyond that, forget it. I've
recently tried a new workflow which uses real terrain and the results are WAY
better than my old approach. This is also a faster process than what I did in
World Machine using splines, the results speak for themselves really.
http://www.outerra.com/forum/index.php?topic=326.30
The downsides are that you are locked into the resolution of the source data,
and you can't guarantee correct drainage at the smaller scales (I can get it at
larger scales because I use two layers of terrain: a low res base with correct
flow, and the top r-w terrain layer). Fortunately there's enough fractal
information in the terrain to offset that- it's complicated enough to prevent
you easily seeing the obvious defects (if you even care about correct flow).
It'd be great to be able to work in watersheds. I define my terrain by
mountain ranges, hilly areas, and rivers. For me, rivers are probably the most
important feature on the landscape because they define the landscape at every
point.If I could divide the map up into watersheds (from continental divide,
downwards), I'd work on those as individual polygons, but the tools aren't
there to work at those scales anyway, and finding real world terrain watersheds
that match the shapes of the poly would be a very time consuming process, and
wouldn't guarantee correcr flow in any case.
Well, you can divide the entire planet into watersheds. It may not be visually
obvious which way water will flow (such as it is in mountain ranges), but
gravity takes care of that at every
point.http://en.wikipedia.org/wiki/Drainage_basin I think what we need is a way
to duplicate that image top right in the last link.The user defines the extents
of the catchment area, and also the face on the poly that represents the
highest gorund. Or rather, provide a tool that enables you to draw the main
backbone ridge. You would then have a tool that generates an l-system-like
river network within those two constraints.
Global Mapper has a watershed analysis tool, which you can run on any terrain,
which outputs polygon areas. That could be a useful bit of code, but I don't
know how straightforward something like that would be to implement.
To be able to generate an interdigitating network of ridges from that initial
river network would be another major asset.You could go the other way and just
provide the tools to gen the ridges and let erosion take care of the rest.Maybe
provide simple spline to draw the backbone ridge and then be able to grow trees
of ridges off that.Or, define watersheds that lie along the main blackbone and
then gen the trees withn those constraints again.
I think either way you do it, you'd need to store the networks with a
hierarchical description, that'd make manipulation of them for other things
possible. Maybe use Strahler networks.
Just throwing some ideas.
Carl
----- Original Message -----
From: John Gwinner
To: leveller@xxxxxxxxxxxxx
Sent: Friday, October 14, 2011 1:00 AM
Subject: [leveller] Re: Image overlay utility
That's a more general topic, but I would agree.
>> You can throw a ton of erosion at something but it won't give you those
drainage patterns if the underlying forms are not there already set up. <<
I use Worldmachine a lot, but it's vector tools are just weird. I find it a
lot easier to rough up a general image of what I want in leveller, then add
detail like ridges (voronoi), dirt (perlin's) and stuff, then erode it like I
like and add snow to it.
Leveller is so much better for that initial input.
Then I bring it back out in Leveller and play with it some more - getting rid
of something blocking the near field, that kind of thing. You can spend hours
with node based procedural editors that takes a few minutes with leveller.
Then into Carrara (ug), Poser (ug), or other app for rendering.
I'm dealing with so many weird bugs in Carrara I may have to break down and
get Vue, even though it's not as extensible via SDK.
== John ==
From: leveller-bounce@xxxxxxxxxxxxx [mailto:leveller-bounce@xxxxxxxxxxxxx] On
Behalf Of Carl Lingard
Sent: Thursday, October 13, 2011 3:57 PM
To: leveller@xxxxxxxxxxxxx
Subject: [leveller] Re: Image overlay utility
I think you have an opportunity to move the situation forward where no one
else has yet. I know that the erosion sim is not Leveller's strong point, but
you really don't need that to create the underlying structures- the erosion can
be added after. Currently there are lots of apps that can do the erosion, but
not a single one that can create a decent mountain range.I tried it in other
apps and it takes an order of magnitude more work than what's realistically
needed. Even then, it lacked that extra mile that prodedurals can make
possible, comparing the result to real world terrain in a planetary scale
renderer, it was pretty obvious which was which- even after all of that work
You can throw a ton of erosion at something but it won't give you those
drainage patterns if the underlying forms are not there already set up. I'm
really talking about the most obvious form, the mountain ranges.
Carl
----- Original Message -----
From: Ray Gardener
To: leveller@xxxxxxxxxxxxx
Sent: Wednesday, October 12, 2011 3:49 AM
Subject: [leveller] Re: Image overlay utility
I'd very much like to, given how long the vector tools have been present in
Leveller now.
I read somewhere that the Win32 API supports "no hit test" attribute for
windows too, which may allow the applet to not only do overlay but to do it
quietly, so that you can interact with an app lying underneath.
From: leveller-bounce@xxxxxxxxxxxxx [mailto:leveller-bounce@xxxxxxxxxxxxx]
On Behalf Of Carl Lingard
Sent: Tuesday, October 11, 2011 12:46 PM
To: leveller@xxxxxxxxxxxxx
Subject: [leveller] Re: Image overlay utility
:) That's a great idea Ray, and I read somebody suggesting a similar thing
once on a board many years ago. They suggested sticking the overlay onto the
computer monitor! :) Thinking outside the box indeed! :)
Do you have any plans to develop tools to create artificial river/ridge
networks with your vector code?
Carl
----- Original Message -----
From: Ray Gardener
To: leveller@xxxxxxxxxxxxx
Sent: Tuesday, October 11, 2011 7:06 AM
Subject: [leveller] Image overlay utility
As a prelude to a new image overlay feature in Leveller, I've made a
Win32 applet that does the same thing in a more general manner.
If you download and run
http://www.daylongraphics.com/download/usr/ImageWindow dot exe
You'll get a simple window into which you can load uncompressed TGA
images.
Use the "File, Set Opacity..." command to change the window's
transparency (minimum of 25%). Then you can position the window over Leveller
(or any other program, for that matter) to check registration of visual
elements. For example, if you are trying to arrange a Leveller scene that
matches a photograph, you would load the photo into ImageWindow, position the
window over Leveller's scene pane, and then get an idea of what camera
adjustments or terrain modeling would be required.
Ray
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