Population altitude setting T2

[bobbystahr]

Yes, I too had a simplistic view of fuzzy zone as being half the amount of meters up and the same down of the height.

That must be one WIKI I read and remembered, but I as well wondered why they (fuzzy zones) weren't in meters like all else terragen.

[jo]

Hi,

It is a bit of a confusing parameter. That's why I wrote the docs, when I really looked into it I realised it didn't work the way I thought either! I think the "times 5" rule of thumb is possibly the easiest way to make use of it. Multiple the fuzzy zone value by 5 and that will give you the distance in metres where the things are essentially fully opaque. It also helps to think of that curve getting steeper as the value gets smaller.

Regards,

Jo

[bobbystahr]

Thanks Jo...formula entered into my TGbrain....

[bobbystahr]

So,.... here's what I found...will let the image talk for me...strange behaviour for sure...that's a 100m ss shader btw

[dandelO]

I've always had the idea that slope fuzzy zone was in degrees and altitude was in metres. That a constraint = 45° with Fuzzy Zone = 5 would mean the full range was between 40°Min'-50°Max'. And that the altitude zone was based in metres, eg: 50m max' height, with Fuzzy Zone = 25, would mean full coverage at 25m and fading out towards zero, at the 50m point. Confusing.

[jo]

Hi dandelO,

I'm not 100% sure what the situation is with the slope fuzzy zone. I had meant to add information about that to the docs but I see I haven't. We'll try and address that before too long.

Regards,

Jo

[Kadri]

I recently tried the min and max fuzzy zone with negative numbers and didn't got what i wanted.
It changes very much if you try it. So i had to change the scene entirely.
Wish i had looked at the docs.

Interestingly nobody much complained including me.
I always thought i had done something wrong anywhere

Jo is it too hard to change it to a basic metric parameter ?

[bobbystahr]

I've always had the idea that slope fuzzy zone was in degrees and altitude was in metres. That a constraint = 45° with Fuzzy Zone = 5 would mean the full range was between 40°Min'-50°Max'. And that the altitude zone was based in metres, eg: 50m max' height, with Fuzzy Zone = 25, would mean full coverage at 25m and fading out towards zero, at the 50m point. Confusing.

that was what I thought as well man,,,,also why does only increasing the fuzzy zone raise the height? as in my previous post

[Kadri]

... why does only increasing the fuzzy zone raise the height? as in my previous post

As i understand it think about the Max and Min fuzzy zone as a horizontal bar.
The Max with 0 (zero) is a straight line. By putting bigger numbers in there the line gets fuzzier to the bottom.
The Min is the same but it gets fuzzier to the opposite side so to the top.

Basically with bigger numbers the underlying texture is more seen
and the horizontal line of the surface layer color vanishes slowly from top to bottom and from bottom to the top.


[attachimg=1]

[bigben]

Increasing the fuzziness doesn't increase the height. Think of it more like 2 consecutive adjustments. 1) It increases the width of the fuzziness and 2) it changes the contrast of the fuzzy zone mask. The first image shows a fuzzy zone of 200, with a pink contour in a separate shader showing the elevation limit. The second image has a colour adjust shader thrown in after the distribution node that effectively removes the fuzziness, showing that it does extend all the way back to the elevation limit, it's just so faint that you can't see it.

By using a combination of a distribution shader and a colour adjust shader you can achieve a wide range of altitude effects that may be a little easier to get what you're expecting.

[Dune]

That's an interesting addition, Bigben, one I didn't use yet, but very handy. I did use it with a (blue) smooth step and 2 constants, where the constants were the heights.

No matter how it works; a surface (or distribution) TEST shader at the end of the line will always be handy to test whatever you want, be it heights, fuzzies, angles or power fractal distributions.

[Kadri]

Increasing the fuzziness doesn't increase the height...

Ben i know what you mean and you are kinda(!) right in that way.
But putting it in that way makes it especially for beginners a little more confusing if you ask me.
You are changing the fuzzines basically to 0 (Zero) ones again
that we are trying to understand to begin with
when used with bigger numbers then zero (i know you stated that yourself too in your post).

I am preparing some more detailed basic images to show more clearly what i already meant in my earlier post.
And no i don't say that i understand all what is going on.
I only try to show what i understand and try to get confirmation if i am right or wrong.

[bigben]

I can understand how it may be confusing, but it is an important to note that the fuzzy zone doesn't change the altitude limit of the shader, especially in this case where a non-zero value in the shader, no matter how small, could result in the placement of an object. If you adjusted the elevation and fuzzy width visually, you would risk getting objects placed below the desired altitude restriction.  My example was only intended to demonstrate that non-zero values in the fuzzy zone did indeed extend all the way to the limit set even though the resulting surface looked to be a long way off.
If you are going to explain this to people I would only use one restriction at a time to avoid overlapping fuzzy zones.

The 2 images below compare a fuzzy zone of 200 (left) with a linear gradient (right). 3 colour contours: Red = min altitude, green = min altitude + 200, blue = min altitude + 5x200
The first image has a linear gradient of 1000m (attached TGD), matching Jo's explanation of approx 5x fuzzy zone to reach an opacity of 1. The second has a linear gradient of 200m. According to the graph in the wiki, the fuzzy shader has an opacity ~65% at the point where the linear gradient reaches 100%.

[Kadri]

...
My example was only intended to demonstrate that non-zero values in the fuzzy zone
did indeed extend all the way to the limit set even though the resulting surface looked to be a long way off.
...

Yes absolutely.

One part i didn't get before was why it behaved strange (especially with negative numbers).
Now we know better because it wasn't any metric parameter.

The other part for me was in which way the fuzzy zone expanded Ben.
I mostly think visually and if i can't transfer the parameters to a visually understandable way i use only trial and error.
And that isn't much a productive way to work.

Instead of posting 9 different images i am posting 1 animated GIF with 8 seconds duration between every picture.
I hope it is easy to watch.

But it is important that where i wrote "Opacity border" in the GIF it is only the kinda viewable fuzzy border.
As Ben said above the real border is still what is shown in the Max and Min altitude settings.


I want to make a test with negative numbers too but there is only really 1 think i am curious.
Because if you put a negative number in the fuzzy zone they go to the opposite side then here shown.
But with 2 negative numbers (in the max and min fuzzy zone together) only the underlying color shows up.
So no surface layer colour is shown at all in such a setup in my tests.


[attachimg=1]

[Kadri]

Using negative numbers in only the Min or Max altitude options doesn't get any surprise.
It is the same as in the above post only in the lower part of the Planet.


[attachimg=1]


[attachimg=2]




But using negative numbers in the Max and Min fuzzy zone options is different.


[attachimg=3]



* With even a small negative number in the Fuzzy zone like  -0.0001 you get a image like in "1" or "2"
   and it is the negative of using 0.0001 as you see in this picture below.

[attachimg=4]


* If you enable Min and Max altitude options together but with only one Fuzzy zone being negative
   you still get the same "1" or "2" picture depending in which Fuzzy zone (Min or Max) you used the negative number.

* The fuzzy zone goes in the opposite direction with bigger (smaller?) negative numbers.

*  If you use negative numbers in both sides of the Fuzzy settings you don't get a Surface colour at all ( "3" ).