Planetside Software Forums

OK, so I'm working on a mountain image and am using a WM generated terrain as well as the colour map.
Then I am using Martin's Snow Pack (still available at NWDA, but purchased quite a few years ago) to add some more depth to the snow (from the colour map).
Despite the example files, I am still having a few issues due to my lack of knowledge.
1.I wanted to increase the size of the clear areas (ie. where there is no snow) as my terrain is quite large (see screencap "Red Sphere..." which illustrates the scale of the area receiving snow).
  I sort of achieved it by increasing the Coverage of "Thick Snow" surface layer from 1 to 3, but am unsure whether this is how I am supposed to do it or whether there is a better (correct?) way?
2.I also wanted to make the snow layer thicker; again, because my terrain is quite large and I want the changes to be visible.
  I discovered (after some play) that increasing the displacement offset of the "Thick Snow" surface layer from 0.05 to 2.0 gave me thicker snow, but in the snow "spaces" the "wall" of snow takes on  some of the colour of the layer below it [see screen cap (Crop render) as I know I am not making much sense here].
What is causing this?
Am I doing something wrong?
Is there a better (again, correct?) way to make the snow thicker.

The ReadMe mentions a bit about the intersect underlying feature:-

QuoteFirst of all there is a VERY important aspect of the "smoothing effect" feature which should be explained in order to make good use of this clipfile.
The intersect underlying type for this snow is set to "displacement intersection" and Terragen 2 automatically enables the smoothing effect function in the surface layer node.
The smoothing function does what it says, basically. The displaced features by intersect underlying will be smoothed.
Smoothing set at 1 will result in almost completely smooth displaced surfaces.
When you reduce the smoothing more details from below the snowsurface will appear.
Here comes the important aspect: the details seen by reducing the smoothing are the details of your underlying terrain BEFORE the last "compute terrain/normal".

The reader is then directed to some "recent" videos explaining this feature better at http://nwda.webnode.com; which no longer exists, so no luck there.
In desperation, I went to the Planetside Wiki (!) to the Surface Layer - Effects Tab, which is still WIP (since TG2 was released; so how many years is that now?) with all the relevant features having the all-too-familiar acronym, TBC (or should that be, CBB.... I'll leave it to your imagination).
So I have no idea as to whether this feature has a part to play in either of my issues as I don't really understand it and have "only" this forum in which to seek help..........
Any help will be much appreciated.

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Hi Erwin,

Can you send me the .tgd file of your project? If it has a heightfield, please include that too.
My e-mail is in my profile here (just click on my username).

Hi Martin,
Sorry, but I can't find your email in your profile - there isn't even a section for it; only the number of posts, Gender, Age, Location, Date Registered, Local time and Last active [unless there is another section that I missed?].
Also, my terrain file is 512 MB; not a size I'm able to email; does the resolution matter for determining what I am doing wrong (or for the intersect underlying feature)?
Even at 4k, the terrain is 32 MB, so I'd have to reduce it to 1K, I think.
Do you need the colour map (it's also quite large at 96 MB and that's for a 4K map; the 16K one is 1.5 GB!).
In case you're wondering, I found that using a hi-res terrain (16K from WM), gave me the detail I wanted around the peak but a bit too much on the slopes (I have yet to work out a Terragen solution for this); using a 4K terrain and adding fractal detail doesn't give the same results as using the 16K terrain.............
I'm using a 4K colour map because the texture looks nicer than the 16K one.......
Anyway, if the resolution of the terrain and maps has no impact on the snow setup, I can just put together a tgd with lower res contents and send that to you (once I work out your email).....

Hi Erwin,

Right, I see. I think my e-mail is only visible to myself then ;)

I need everything except vegetation models.
Let's try the 4k version of the whole first. There's a chance that the more detailed 16k version will give different results with the same snow layer, so be aware of that in advance.
I suggest you use the "export gathered project" tool from the File menu to save the assets to a separate folder.
Then ZIP/RAR that folder and send it to me through something like WeTransfer.com or Dropbox.
My e-mail is m_huisman at hotmail dot com

I hope this works for you.

Martin

I suggest using 7-zip (or RAR) if you can. Much smaller file sizes than .zip. :)

- Oshyan

OK Martin, I'm kinda happy to see I wasn't wrong about the email as well....... ;)
I'm getting the file/s ready as I type this; even the crop render is slightly different when using the 4K .ter file as opposed to the 16K one - nicer for the slopes but the peaks look better with the 16K file.
Right, the gathered compressed report is only 48 MB; I think I'll try the hi res version as well.............

So I've uploaded both to Sendspace. Below are the links (I am happy for anyone else to grab the files and use them as they want. Just for anyone interested; it's meant to be an alien terrain and I'm not that skilled at WM  :)).
Low Res:   https://www.sendspace.com/file/1slap9   (47.86MB)
High Res:  https://www.sendspace.com/file/uilxj8     (247.08MB)
Thanks for taking the time to have a look.........

Oshyan, Yeah, I generally use 7-zip; not only is it free, it's far more "resilient" to file corruption than either (Win)zip or rar............

Hi Erwin,

I just checked and noticed a few things, of which some important:

1) The image map shader should be disabled when assessing the snow shaders, as it's bright too.
2) You still had the default fractal terrain + fractal warp in the scene, which also affect your imported terrain.
This could be intentional, but I have the gut feeling it isn't.
3) Whenever doing things like stones/snow, which require a smoothed surface layer to work properly, you better disable "fractal detail" in your heightfield and use PF's instead to give the terrain some detail.
4) The terrain itself has spikes exactly where you don't like your snow cover. I suggest you get rid of those spikes, because no matter what you try with the snow, the spikes will remain.
5) You used 2 snow shaders which both used a smoothed surface layer and intersect underlying enabled. It's very difficult to predict how these 2 surface layers interact when you configure them differently.
It's best to restrict both layers by altitude and make sure that 1 snow layer does not completely intersect with the other.
(I set the lowest layer to exist up to 250 meters altitude with 50m fuzzy zone and the top layer I set minimum altitude to 250 meters altitude with 50m fuzzy zone)

Hi Martin,
In an attempt to follow your guidelines, I thought I'd first start by combining 2 heightfields; one the 16K ter and the other the 4K ter, both in the same location and both having the same settings wrt size.
What I was trying to do was have the high resolution of the 16K ter at an altitude above 330 m and the lower resolution of the 4K ter below 330 m.
As the heightfield load/shader have no facility for setting a cutoff at a given altitude, I thought I'd try first the heightfield clip vertical but it simply removed the terrain completely, no matter the settings.
Then I tried the heightfield adjust vertical; although not as "obvious" to use for this task, the wiki implied that either of these two shaders could do the job (or at least show me some sort of effect to see what was happening).
Of course, it again removed my terrain completely!
I think I'm trying to do something rather basic but the lack of basic information is making it not - basic.
The whole reason for this is to get rid of the spikes you mentioned and, frankly, it's the only way I can think of to do so (my WM skills are almost as low as my Terragen skills)...

So, after that extended whinge; how can I do what I am trying to do (ie. blend the two terrain resolutions so that below 330m, we have the 4K ter showing; and above 330m, we have the 16K ter showing)?............
Sorry that you need to teach me these basics before we can solve the snow issue (which may resolve itself once your recommendations are met)..............

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Hi Erwin,

Don't worry, we just go through it slowly step by step.

Here's an example showing you how to blend 2 terrains by altitude.
The merge shader uses the default settings and all other settings of the distribution shader are also at default, so I only changed the altitude restriction parameters.
The 4k heightfield had a tiny little bit difference in altitude range so I made that the exact same as the 16k version.

From here on you should be able to move forward and just let me know if you run into problems.

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Hi Martin,
Thanks for your understanding. I appreciate it.
I won't be able to work on this until later tomorrow, or the day after but I thought I'd respond now so you know I'll keep coming back until my issue is solved (and learn lots of "btw info" in the process  :)).........

Sure, no problem, I'll keep an eye on it.
If you think I'm missing out somehow then don't hesitate to drop a line.

OK, It appears that I am to be the remedial learner; I just don't understand your meaning when you state:-

QuoteThe 4k heightfield had a tiny little bit difference in altitude range so I made that the exact same as the 16k version.

The 4k heightfield had a tiny little bit difference in altitude range than what? As the Distribution shader determines the altitude, and there's only one, how can you set different altitudes for each terrain?

OK, I've been staring at your node setup for 20 or so minutes and reading/re-reading the node descriptions in the Wiki:-
I'm trying to work this out for myself, so I am writing down my thoughts as I work through your setup; so please forgive me if I repeat anything...........
"The 4k heightfield had a tiny little bit difference in altitude range so I made that the exact same as the 16k version."
Is this determined within the respective Heightfield loads (4K & 16K)?
Height range: min = 0mm, max = 1.87km, range = 1.87km (16K); Height range: min = 1.22m, max = 1.88km, range = 1.87km (4K).
And is this why only the 4K HF Load has a HF adjust vertical node when the 16K HF load does not (since the 4K HF is "laid down" over the 16K HF it needs to make what is already there)?
If this is the case, would the HF adjust vertical settings be;
Set height range checked. Highest = 1870m, Lowest = 0m
Multiply by height left checked & set to 1 or unchecked (so HF remains unaffected by this parameter)
Add height left unchecked
Right; I think I may be winning the first little battle - by checking the "Apply colour and shade" parameter within each of the Heightfield shaders and changing their respective colours (and disabling both the snow shader networks, Base colours & Image map shaders); I was able to visualise the 16K HF and how far up the 4K HF lay!
So the blending of the 2 terrains by height appears to be working.
So now I can finally look back to your snow shader and see how it looks now............
Well, the snow is pretty nice now. I must admit; I really didn't think that disabling the image map shader would have any effect other than making the actual snow shader easier to see - but it actually changes the shape of the terrain surface! Wow!

Despite this (as well as other revelations); we still have the original issue of the "snow space walls" taking on the colour of the layer below it (it may not be that exact problem; I am content to refer to them as render artifacts).
Crop renders of the snow layer with and without the Image map shader being enabled, showed me that the "snow space walls" manifest differently in each scenario.
Reiterating the questions asked in the original post (I realise that there were many other issues to deal with first before coming back to these questions);
Is there a better/"more correct" way to make the snow thicker?
Is increasing the displacement offset of the "Thick Snow" surface layer from 0.05 to 2.0 an acceptable method of increasing the snow thickness?


Your recommendations.
"I just checked and noticed a few things, of which some important:"

1) The image map shader should be disabled when assessing the snow shaders, as it's bright too.
I thought that this meant changes would be difficult to see; not that the image map combined with the snow shader results in changes to the shape of the terrain surface!
2) You still had the default fractal terrain + fractal warp in the scene, which also affect your imported terrain.
This could be intentional, but I have the gut feeling it isn't.
It wasn't; both have been removed from the network.
3) Whenever doing things like stones/snow, which require a smoothed surface layer to work properly, you better disable "fractal detail" in your heightfield and use PF's instead to give the terrain some detail.
Done; how do I use and control power fractals to give the terrain further detail {if there are any tutorials, detailed descriptions, etc known to you, plmk}
4) The terrain itself has spikes exactly where you don't like your snow cover. I suggest you get rid of those spikes, because no matter what you try with the snow, the spikes will remain.
I think blending the terrains removed this issue......
5) You used 2 snow shaders which both used a smoothed surface layer and intersect underlying enabled. It's very difficult to predict how these 2 surface layers interact when you configure them differently.
It's best to restrict both layers by altitude and make sure that 1 snow layer does not completely intersect with the other.
(I set the lowest layer to exist up to 250 meters altitude with 50m fuzzy zone and the top layer I set minimum altitude to 250 meters altitude with 50m fuzzy zone)
Note:- Originally, first snow lay was set to cover the entire mountain up to 700m  [fuzzy = 200m] (leaving the top peak marginally clear of snow); the second snow layer up to only 340m [fuzzy = 70m].
I changed my setting likewise (with exception of the higher layer max altitude being limiter to 700m [200mfuzzy] to leave peak relatively free of snow (except for that from image map).......


Also (separate from this); your example file, "TU snow.tgd" is missing a .ter file (Stillwater.ter); I hunted for it in the forums but only found mention of it once in an image sharing post... Would I be able to ask you to post here or upload elsewhere so I may explore the scene you provided.The "TU snow2.tgd" works fine but different files often present different snippets of knowledge.... ;).
There's also a texture missing and it would be nice if that could also be included but if that proves too difficult, I can always use another texture (But even texture selection can be instructional in and of itself).

Sorry for the length of the post.................. :-[

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Hi Erwin,

Well....that's quite a lengthy post indeed.
I'm not sure where to start, to be honest.
I just can't explain all the things you're asking, because most questions run down to the most basic concepts.
There it becomes difficult for me, because you ask for help, but it seems you need spoon feeding of the concepts of TG.
It's not that I don't want to, not at all, but it's simply not possible here just by text.

Can you strip down the project file down to the terrain and only 1 surface layer, then ask precise direct questions 1 by 1? 2 by 2 is also ok, you feel me ;)

Hi Martin,
Well, I have to say; you've made me feel like, how dare I ask the questions that I have?!
I am now on my fifth attempt at learning enough of the basics of Terragen so I may create my own work rather than follow step by step "recipe" tutorials.....
To be honest; I would be perfectly happy to not ask any questions whatsoever and work things out by using the manual/user guide - but, well... you know why I can't do that.............

Quote"Don't worry, we just go through it slowly step by step."

As for "spoon-feeding" (a rather offensive term); users wouldn't need to be spoon-fed if we were provided with our own spoon (aka. user-guide). The Wiki still has the same WIP signs for topics originally created when Terragen 2 was in the "Technology Preview" stage............
I realise that is not your fault/responsibility; but this is why people such as myself have so many questions. We are the product of months of frustration trying to learn a program that some appear to understand almost immediately, but others (myself included) just can't manage to grasp.
This is due to the majority of the Wiki (at least the parts of the Wiki that exist) has been written by (it appears) one person (Oshyan?).
As there are four distinct learning "styles"; something written by one person (whose learning style is generally the same as their teaching style) will only address the learning styles of a quarter of the people attempting to learn what is being taught.
This, of course, assumes no overlap in learning styles (which is rarely the case; in reality, there are 7 learning styles but the most common combinations are four in number. I am "Visual-logical" - NOT one of the four "common styles") but I used the "absolute" example in an attempt to get my point across; although the amount of learning material for Terragen is increasing; the vast majority is aimed at roughly 25% of those wanting/trying to learn the program.....
Lastly; I perhaps ask a lot of questions because I learn by knowing "why"; not just "how" and I was a high school Maths/Science/Art teacher for 25 years (teachers always make the most demanding learners. NOT by choice, but by circumstance)....

OK, enough of the lecture; I will try to break down the previous post to 2 or 3 posts; asking the same questions..........
And I'll try to keep the questions in this post related to your snow shader.

Here are my questions for this post:-

1.What is causing the "snow space walls"/render artefacts?
2.Is using the displacement offset the way to increase snow thickness?
3. Is there a better/"more correct" way to make the snow thicker?

BTW; I asked a mere 7 questions in the previous post; some which I had asked several times before (but have kept on asking as they hadn't yet been answered).
Most of the post was a "running commentary" of my thoughts (which I had noted near the start of the post):-

QuoteI'm trying to work this out for myself, so I am writing down my thoughts as I work through your setup; so please forgive me if I repeat anything...........

To answer your question: " Can you strip down the project file down to the terrain and only 1 surface layer, then ask precise direct questions 1 by 1?"
No, because the main problem shows when your snow shader covers a heightfield terrain with an Image map shader.
These are the conditions under which the issue occurs; changing these makes the original issue/questions mute............
If you can tell me exactly what to do to the project file to make things more manageable, please do; I just can't see how I can and still keep the same issue present in the file...
I am sorry if this post comes across as aggressive; that is not my intent. I am just trying to learn and can only learn in a step by step, visual manner............

Hi Erwin,

Don't worry, I said:

QuoteIt's not that I don't want to, not at all, but it's simply not possible here just by text.

So your feeling is not justified I'm afraid.
I think I can see why you feel like that, because I think you do not realize the complexity of the questions.
"Thick snow" is by itself a rather simple concept. Right?
However, practically, and especially with this rather advanced snow shader, it's anything but simple or straight forward. It requires experience and good understanding and that's something I just can't do for you.
So my rejection of going through all of this completely seems like denying you something small/simple and not too much asked, but I'm afraid it actually is in reality.


The reason I asked to strip down your project to just the blended terrain (blend of 4k and 16k I showed you) and 1 snow surface layer, is because you have a simpler setup then.

The snow surface layer is *not* affected by the image map shader. That's a misconception.
The image map shader contains a texture which is mostly white.
Assessing what the snow surface layer is doing when the underlying surface is *already* white because of the image map shader, is simply nearly impossible.

If you'd like to do that and render out the snow as it looks + attaching a .tgd then we can work through it step by step.

Hi Martin,
OK, I think I get your meaning; sorry if I over-reacted.
I'll get a simpler version of the scene organised and repost when that's done.
I do understand that the help I am seeking is complicated, but perhaps I do not yet understand just how complicated it is...........

Hi Martin,
OK, I've made up a simplified version and have also done a considerable amount of experimentation.
https://www.sendspace.com/file/qebaih
The image below shows 14 crop renders of a region with the issue I am having the most difficulty with; what looks like torn geometry due to displacement.

[attachimg=1]

Each of the crop renders has some numbers in the top left-hand corner stating the Displacement offset first and then the Coverage second. eg. 1   |   3 means Displacement offset = 1, Coverage = 3.
Although each render shows the torn geometry (?), it appears that increasing Displacement offset has the most effect (ie. makes it worse).
What I am trying to achieve is the appearance of thicker snow and, although increasing either the Displacement offset or the Coverage results in thicker snow; they also result in worsening torn geometry (?).

[attachimg=2]
So, my question is; how can I be rid of this issue and thicken the snow layer?

Thank you for your patience.
I hope that this question is one with a relatively simple answer, but I doubt it will be somehow..... ::)

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Hi Erwin,

The near-discontinuity here is caused by the thick snow shader ("Thick Snow 1_1_1") being masked by other shaders, and those other shaders are generating a fairly sharp transition from black to white. At one point the mask is generating black (0), which masks the show displacement down to 0, and the next it is signficantly above 0. The main culprit is the high gamma in the Colour Adjust Shader. It helps when I change the gamma from 2 to 0.5.

As I'm speaking to a mathematician, gamma 2 raises to the power of 0.5, and gamma 0.5 raises to the power of 2. If that seems backwards, it's because I'm following the computer graphics convention for gamma correction of images in which higher numbers produce a brighter image, so we raise to the power of 1/n.

By changing the gamma from 2 to 0.5 I was able to push the snow's displacement offset up to 10 without seeing much of a problem, at least in the final image. With lower displacement, a gamma of 1 might be OK too.

However, I don't think this completely solves the problem. Watching it render the micropolygons, I don't think the surface is being displaced how we'd want it to, and the colouration of the surface doesn't seem to match the displacement properly. Generally I would say that masking one Intersect Underlying shader with another Intersect Underlying shader is going to be unpredictable. Intersect Underlying wasn't designed to be used as a mask, and to be honest I'm not sure what's happening when both the masked shader and the mask-generating shader use that feature. It's also unnecessary (and sometimes erroneous) to have the terrain input into the mask-generating shader.

If you can, try to get something you like without the extra snow shader "Thick Snow_1_1" as a mask. And in general, when masking displacements, use masks with shallow gradients. Perhaps that was your intention with the gamma of 2, but I don't know if that came from Martin's setup.

Unfortunately Intersect Underlying is one of the features I find the most difficult to explain how to use, and I also often struggle to get it to produce good results on demand. The shader is trying to be too clever and gets into trouble more often than I'd like!

Matt

Yes Matt, I noticed Erwin somehow used an "intersect underlying" layer as a mask as well.
This is a down-side of plug'n'play shaders; having a drivers license is one, driving a race car is something completely else.
Intersect underlying in general and this snow shader especially, is ideally for advanced users.

The problem is that the explanation of intersect underlying is required for understanding this shader.
With the help of your basic preliminary documentation I have developed some intuïtion for this shader, but saying I can explain it myself in layman's terms? No.

I reworked his file last night and it uses 1 surface layer with intersect underlying enabled, but without any masking.
I will upload this project file tonight.

Hi Matt,
The maths I understand; the rest...... well, let's say, I'm confused but I'll have another look, rereading all the time what you have written and see if I can understand further.
As I am using TU's Snow Pack, I'll have to look further into it to see what you mean (I am thinking you're referring to the node chain; Colour Adjust > Power Fractal > Thick Snow_1_1 that is connected to the mask input of the output Thick Snow_1_1_1? Sorry if I am using incorrect terminology; it's all part of the learning curve).

One of the problems with Intersect Underlying is that there is no entry concerning it in the wiki that I can find (The Surface Layer Effects tab is still a WIP) so I have very little to go on wrt understanding how it works or, tbh, what it does (I believe it "reads" information from the layer below and "reacts" accordingly)...
I am forever reading users complaining about the incompleteness of the wiki and I do realise that given the nature of how Terragen works, it can be quite difficult to explain certain concepts/workings of the program.
There is also the constant request for tutorials and, sadly, good artists don't necessarily make good tutorial writers.
Ironically, having been a teacher for 25 odd years, I am pretty good at writing tutorials and I would happily do so, for free; now all I have to do is learn Terragen first.......... ;)

EDIT:- I was just about to post this when you posted, Martin.

QuoteYes Matt, I noticed Erwin somehow used an "intersect underlying" layer as a mask as well.

OK, I am now even more confused, so I do hope you'll explain what I did wrong.
I freely admit to being quite ignorant of the inner workings of your snow shader so I copied how it was connected in your TUSnow2.tgd.
At least I thought I had......(?)

A few posts ago I already mentioned that having 2 surface layers with intersect underlying are difficult to use as it's difficult to predict how one affects the other.
Matt basically said the same with some additional remarks.

I admit I will avoid as long as possible to explain the intersect underlying feature. That's up to Planetside.

Take a look at the .tgd I will upload later and see if you like it.
It's thick powdry looking snow and I also got a bit carried away with it (the scene), so I also added some stones which help creating the sense of thick snow.

Hi Erwin,

Here's how it looks now.

About the .tgd attached:
Save it to the gathered project folder.
The note shaders contain explanations on a few things.
You can disable the stones and "rock and strata" groups to get the simplest terrain with snow only.

Your head may explode when reading about intersect underlying and the compute terrain node etc.
This is a must read for literally everyone who's touching this software:
http://www.planetside.co.uk/forums/index.php/topic,1249.msg12539.html#msg12539

This should keep you going for quite a while I think :)

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Hi Martin,
Thank you ever so much for all your time.
You are right; this will take me quite some time to go through.
Funny, it's already been downloaded 9 times before I got to it............. ;D
Hopefully, I'll learn something and not bother you so much............
I did also try what Matt suggested and changed the Gamma of the Colour Adjust shader from 2 to 0.5 and that made a considerable difference.
However, the snow in the area that was crop rendered in previous posts looks a bit blurry; I'm unsure why. So I have also attached another crop render sequence.
Other than showing the improvements gained by dropping the gamma setting, it also shows (in the last crop) that I have reduced the Terrain's Distribution shader's Coverage from 1 to 0.6 so as to obtain greater detail at the peak as well as a bit more terrain irregularity on the lower slopes (this added a bit more 'bumpiness' to the snow also which I liked)..
That being said, I will go through all that you have done and, in a week or so, I may have a few questions (he says with apprehension in his... er, voice).......

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