Heightfield as Crater Shader

[WAS]

I understand, but I actually meant if it could be reproduced to more than one location, like a crater field. I guess not. Basically what is needed is random 'dots' to begin with and radiation from those dots.

It's possible Ulco,you just have to replace the "get postion..." by a "Get pos in tex" as usual
in the innards of mogn's setup.And instead of using the input of the "transform merge sh"
you have to combine both iterations otherwise,for instance with a "mix colour" as shown.

[attach=1]

For some reason piping it through the "Transform merge" doesn't work occasionally,that got
me to use other combining methods earlier on btw.
No idea why,though.

Yeah I got what he meant about the vector subtraction. I still don't see the need for rainbow radial lines?

here is another attempt with couple "ancient" craters and the newly blasted craters. Did some adjustments to the masks. Trying to get the right blast radius bigger but little issues.



Doesn't seem to really work on small objects though like a small moon. the Extreme Y axis's don't work with the crater shader apparently. Definitely can't preview it.

[AP]

I was not aware you wanted a series of strata overhangs. In that specific moon crater all i see is a series stair stepping patterns.

[WAS]

I'd love to see someone give their go at this.

I tend to agree, a "Layer and Outcrops" or "Sediment and Outcrops" node might be more appropriately named. However when i think of Sediments (broken down soft rock), i think of the process of deposition with material transport.

I was not aware you wanted a series of strata rock layers. Here in the specific moon crater, all i see is a series of Outcrops.

I love that crater. Though what I'm referring to is a litter further from the impact on the descending sides of the mound. They'd basically lateral protruding disc like layers which were molten at one point created by the blast..



The stratification is a lot older here and more layered out in this one



Something similar on earth



Also I found this as a nice reference of this type of ejecta crater we are doing here:

[AP]

I have never seen overhangs on the moon so i am curious to investigate this more. A more side profile would help better understand the overall structure of what is trying to be achieved here. I'm looking at more photographs to try and find a better perspective in relation to this.

[AP]

Some more references.

[Dune]

@Jochen; Thanks for your input, I understand that too, but I was really talking about A LOT OF ejecta spots, like all over a planet, not just a few more than one. With the vector 3A setup you can get multiple craters (and edges), but getting ejecta out of all those dots would be the final trick. And indeed if you could twist&shear those ridges from the center outward of each of all those dots, you can get the overhangs also. Quite impossible, perhaps....

[mogn]

I understand, but I actually meant if it could be reproduced to more than one location, like a crater field. I guess not. Basically what is needed is random 'dots' to begin with and radiation from those dots.

Random dots:

X = mod(x, 1000)    Z = mod(z, 1000)
X' = subtract(x, X)   Z' = subtract(z, Z)
x2 = build vector(x, 0, 0)
z2 = build vector(0, 0, z)
Finalx = X' + 500*perlin(x2, 500)
Finalz = Z' + 500*perlin(z2, 500)
Random origins = [x, y, z] - [Finalx, 0, Finalz]

[Dune]

Ah! But as usual, this is too magical for me, mogn. Could you possibly put this in a tgc? And can you radiate from this setup?

I've been tinkering as well and came up with this, but I can't put my fingers on the final step; to use the derived 'mask' on a flat area. As soon as you smooth the perlin dots, the nice radial stripes disappear. I've tried translating the stripes into displacement, and using that to derive another mask, but to no avail.
I won't probably use them very much, but it will come in handy. So if someone could takes this one step further..... we would have global ejecta.

[mogn]

My thinking was wrong. The origin must not depend direct of the current point point, but 0f a fixed point inside the square km.

[j meyer]

Ulco - sorry,misunderstanding on my side.

[Dune]

To make it up, just solve the riddle I presented 

[j meyer]

 

[WAS]

All the math hurts my head. :\ lol

[Matt]

WASasquatch, regarding position functions did you see my reply here?

http://www.planetside.co.uk/forums/index.php/topic,20709.msg206143.html#msg206143

Matt

[WAS]

WASasquatch, regarding position functions did you see my reply here?

http://www.planetside.co.uk/forums/index.php/topic,20709.msg206143.html#msg206143

Matt

Oh yes I did. What I tried didn't seem to allow me to move anything, but I may have set it up wrong. This would be nice to move the whole thing without multiple position points.