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General => Image Sharing => Topic started by: sboerner on November 13, 2017, 01:31:04 PM

Title: Antarctic landscape
Post by: sboerner on November 13, 2017, 01:31:04 PM
Rendering of a landscape near Taylor Glacier in Antarctica. This served as the background to an infographic about ice-core drilling, hence the odd composition with the empty space in the center.

[attach=1]

I've been away from Terragen for several months and procedural landscapes are not my strong suit. Normally I would use DEMs for this kind of project, but I could not track down a high-resolution DEM of this area.

So it became an education. I learned how difficult it is to mimic real-world topography with procedural tools. Especially glaciated terrain with lots of erosion. And no vegetation cover, which made it all the more unforgiving. But the deadline was pressing, and this seemed close enough.

Thoughts and suggestions welcome. I really want to improve my procedural skills so the next project goes a little more quickly with better results.

Here is an aerial view of the real place:

https://commons.wikimedia.org/wiki/File:Taylorglacier_pho_2013_studinger.jpg#/media/File:Taylorglacier_pho_2013_studinger.jpg (https://commons.wikimedia.org/wiki/File:Taylorglacier_pho_2013_studinger.jpg#/media/File:Taylorglacier_pho_2013_studinger.jpg)
Title: Re: Antarctic landscape
Post by: Oshyan on November 14, 2017, 05:53:36 PM
I think you did a pretty good job. It seems like a very odd-looking place that would be hard to create a realistic recreation of since the real place looks "unrealistic"! :D

- Oshyan
Title: Re: Antarctic landscape
Post by: sboerner on November 15, 2017, 10:15:46 AM
Thanks, Oshyan. It is a very surreal landscape on all scales, from the largest mountains to the smallest details of the glacier surface. My main goal here was to just give a sense of the vastness and isolation of the place, so maybe that was enough.

I would have liked the shape of the mountains to be more authentic – sculpted and eroded. I started with the alpine shader but wonder if I should have used heightfields instead. I'm not completely clear how heightfields and procedural displacements interact, and need explore that. Now that the deadline pressure's off I can rebuild it and try a few things.
Title: Re: Antarctic landscape
Post by: Oshyan on November 15, 2017, 08:42:49 PM
Heightfields and Procedurals can be freely mixed, generally speaking. How they interact depends on your settings for each. For procedurals, they are "additive" by default, i.e. adding a procedural displacement after another will add the displacement on top. For heightfields the default is actually to "Flatten surface first", so they would replace any existing procedural displacement, but you can disable Flatten Surface, or just add a procedural displacement after the heightfield node to add on top of it. This is very useful for adding small-scale detail to otherwise lower resolution real-world (DEM) data for example.

- Oshyan
Title: Re: Antarctic landscape
Post by: J_Con on November 18, 2017, 05:36:20 PM
I doubt I am the only person who looked at this render and thought...hrm...mountains don't look like that. But it would seem that the truth is stranger than fiction in this case. The foreground object is very nice and a good indicator of scale. Nice job.
Title: Re: Antarctic landscape
Post by: sboerner on November 19, 2017, 03:47:25 PM
Thanks for the comments, Joe. I don't blame you for wondering about the authenticity of the mountains. It's a pretty weird looking place. But I agree with your first impression. Overall the panorama is OK but once you look at it closely you can see the mountain shapes aren't really right.

I decided to rebuild it from scratch and have been taking a crash course in heightfields and heightfield operators. So far I've been skating with Terragen, using it mostly to build maps and large-scale scenes based on DEMs. This is my first real project creating detailed terrain from scratch.

Here's where things stand after a couple of days' work. There's no shading yet, just displacements. This began as a Heightfield Generate node modified with a Heightfield Curve Vertical to create the glaciation effect. Then a bit of erosion added with a Heightfield Erode node. This basic scene was taking up to 30 minutes to load and generate the displacements, so I moved all the heightfield nodes into separate files to generate and export the base terrain and erosion (as a difference erosion field) in two .ter files, combining them in the final scene. What a great feature and timesaver! The working file now loads in a split second, and the erosion can be faded and masked as needed.

[attach=1]

I'm much happier with this because it seems to more closely resemble the original terrain, with its heavily eroded sedimentary rock layers, taluses and debris fields. I can see where some things may need to be tweaked but will wait till it's shaded and properly lit. Thoughts, suggestions and comments welcome.
Title: Re: Antarctic landscape
Post by: sboerner on November 19, 2017, 03:49:54 PM
Oshyan, sorry for the late reply. I've been plugging away on this and wanted to have something to show first. Your comments were very helpful and gave me some good ideas about how to proceed. Sometimes the high-level concepts get overlooked when you get into the weeds of network building. Thank you!
Title: Re: Antarctic landscape
Post by: Oshyan on November 20, 2017, 01:27:15 AM
No worries. Your terrain is looking very promising, great work!

- Oshyan
Title: Re: Antarctic landscape
Post by: Dune on November 20, 2017, 01:52:51 AM
This looks much better than the first render. What you could also do is paint a heightmap in Photoshop in 16bits grey, as good as is possible form eying the area on photo's or google, or even onto a low level (reduced to 16bits) DEM. Then add some procedural extra displacements.  If you need underwater terrain, make a copy of the map and paint it in the black areas, then make the raised areas black and inversely displace in TG. 
Then erode. Daniil's erosion plugin has the benefit of maps. If you need underwater terrain, make a copy of the map and paint it in the black areas, then make the raiswed areas black and inverseyly displace in TG. 
Title: Re: Antarctic landscape
Post by: mhaze on November 20, 2017, 06:53:20 AM
Excellent terrain.
Title: Re: Antarctic landscape
Post by: luvsmuzik on November 20, 2017, 08:18:07 AM
Some neat stuff here.  :)
Some cool features of TG include making groups and notes in the node networks. For ease of navigation and often previewing other settings, you can also disable items in the height field string (or a complex object i.e.) while you tweak others.
Title: Re: Antarctic landscape
Post by: sboerner on November 20, 2017, 10:22:00 AM
Thanks to all. Appreciate the feedback and ideas. Here is the result after the first shading pass. The rock face is looking OK but may benefit from finer detail (more octaves, roughness) in the shading nodes. The ice surface needs some work – less contrast, more specular. Thinking about next steps . . . clouds, foreground objects. Would be nice to include something to suggest wind. I understand that it gets very windy there. (As well as very, very cold.)

[attach=1]

QuoteWhat you could also do is paint a heightmap in Photoshop in 16bits grey, as good as is possible form eying the area on photo's or google, or even onto a low level (reduced to 16bits) DEM. Then add some procedural extra displacements.

That would be a good workflow for a scene like this; might make it more authentic in that you could at least represent part of the original topography. I wonder if you could sculpt the basic mountain shapes in Maya, then export a heightmap that could be loaded into Terragen and finished. May have to try that some time.

QuoteThen erode. Daniil's erosion plugin has the benefit of maps.

Some day, perhaps. (I use a Mac.) Till then, I'm using the built-in Heightfield Erode node. I've learned to bake the results into an exported .ter file (as an erosion field) and merge them with an uneroded heightfield in the working file. The slider in the merge node can be used to fine tune the amount of erosion, and saves a lot of back and forth.

Title: Re: Antarctic landscape
Post by: sboerner on November 20, 2017, 10:50:45 AM
Is it possible to feed the results of procedural displacements back into a heightfield shader? It would be nice to able to apply the erosion after most of the displacements, instead of between the heightfields and procedural sections of the network. I've tried a couple things but can't get it to work.
Title: Re: Antarctic landscape
Post by: Oshyan on November 20, 2017, 04:46:41 PM
Create a Heightfield Generate node and feed your procedural displacement network into the Shader input. Set the "Size in Meters" of the heightfield big enough to cover your area of interest and the "Number of points" top whatever you want the resolution (detail) of the heightfield version to be. Once you "Generate Now", you have a heightfield version of your procedural displacement. Remember that non-planar (e.g. overhanging) features cannot be represented in a heightfield and so will be lost. After generating you can right-click and Save As, just as with other heightfields.

- Oshyan
Title: Re: Antarctic landscape
Post by: bobbystahr on November 20, 2017, 04:58:50 PM
Quote from: Oshyan on November 20, 2017, 04:46:41 PM
Create a Heightfield Generate node and feed your procedural displacement network into the Shader input. Set the "Size in Meters" of the heightfield big enough to cover your area of interest and the "Number of points" top whatever you want the resolution (detail) of the heightfield version to be. Once you "Generate Now", you have a heightfield version of your procedural displacement. Remember that non-planar (e.g. overhanging) features cannot be represented in a heightfield and so will be lost. After generating you can right-click and Save As, just as with other heightfields.

- Oshyan

Wowzers...there's something I've never tried...thanks Oshyan and sboerner for this thread.
Title: Re: Antarctic landscape
Post by: sboerner on November 20, 2017, 05:03:14 PM
QuoteCreate a Heightfield Generate node and feed your procedural displacement network into the Shader input. Set the "Size in Meters" of the heightfield big enough to cover your area of interest and the "Number of points" top whatever you want the resolution (detail) of the heightfield version to be.

Thanks, Oshyan. I thought I tried that but I must have missed something. Maybe the bit about setting the size and resolution. I'll give it another go this evening.

Just curious: How is displacement data transmitted through the network? As vectors? (I suspect there's more to it than that.)
Title: Re: Antarctic landscape
Post by: Matt on November 22, 2017, 06:15:18 PM
What's transmitted through the network is something called the "Render State", which contains not only the position of the current point in space but also a few other variables. I've written some more about that here:

http://planetside.co.uk/wiki/index.php?title=Render_State

Matt
Title: Re: Antarctic landscape
Post by: sboerner on November 27, 2017, 10:14:46 AM
QuoteWhat's transmitted through the network is something called the "Render State", which contains not only the position of the current point in space but also a few other variables.

Thanks, Matt. Good information in that link, and in the individual shader descriptions as well. Slowly, slowly starting to get my head around all this.

QuoteRemember that non-planar (e.g. overhanging) features cannot be represented in a heightfield and so will be lost. After generating you can right-click and Save As, just as with other heightfields.

Piping the procedural network back into a heightfield worked like a charm, Oshyan. The network included some lateral displacements and a strata shader. Both were lost and I assume are among the non-planar features that you mentioned. But still a good option to keep in mind.
Title: Re: Antarctic landscape
Post by: sboerner on November 27, 2017, 10:20:58 AM
Final version of the revised scene. (For now – still seeing some things that need tweaking.) Calling this "Midnight at Taylor Glacier."

Title: Re: Antarctic landscape
Post by: bobbystahr on November 29, 2017, 09:35:32 PM
Well done.
Title: Re: Antarctic landscape
Post by: sboerner on November 29, 2017, 11:48:39 PM
Thanks, Bobby. It's a start. I sure learned a lot.
Title: Re: Antarctic landscape
Post by: J_Con on November 30, 2017, 07:39:57 AM
Nice crunchy looking snow/ice. That environment is such a strange place.Nicely done.