Snow quest... again

[Alfamike]

Hello TGers,

I've been reading up about making snow in TG2 on this forum, but not happy with my results.

Have come up with two ways which ought to make decent snow but am struggling putting the functions together.

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ONE:

Based on height maps. Have a height map, put the output through an erosion filter and then - her lies my problem- put it together with original height map selecting by maximum height.

I take the output of the erosion, plug it into a Get Pos, also put the output of the orginal height map into a Get Pos, both through a Conver to Scalar and then I pick the highest elevation with IfThenElse, this output goes into the Y of a Build Vector, the X&Z come from either one the eroded or original height map, via Convert to Scalar. The Build Vector goes into the Displacement input of a displacement shader and then to computer terrain.

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TWO

Same as above function-wise, but with a fractal terrain, one original and a copy, but smoother (and with a slightly smaller amplitude)


What is my mistake in the functions. I think it's the Build Vector but have not worked out a way to get the right results.

Thanks for looking and helping.

AM

[Alfamike]

Hey Hillrunner,

Thanks for the reply. Will try later today.

Still want to get may way working though as I think it should be a way to get decent snow in most normal terrains. Not too dependent on pov and sun etc.

AM.

[rcallicotte]

Thanks, Olivier.

[Alfamike]

Hi Hillrunner,

Thanks, that works well. Still trying to get my head around the effect settings and options, but am getting there your way.

Still struggling with my other way. Taking "XZ from one fractal" and a Y value depending on which ever of the two fractals has the highest value.

I get the resulting XYZ's no problem, but then don't get it to work in a displacement shader.

Anyone any suggestions? Thanks for helping.

AM.

[Alfamike]

Hi guys,

'fraid I have not solved my case yet. Help would be much appreciated.

For my snow project I want to combine two terrains. These terrains are pretty similar. The resulting terrain needs to contain the elevations which are highest (or lowest).

My problem is to reconstruct the terrain once I have determined the final elevation. Please refer to screen shot. What do I need to put at the question mark to rebuild the terrain using the elevations that come out of the conditional scalar?

Thanks for your help.

AM.

[Kevin F]

Hi guys,

'fraid I have not solved my case yet. Help would be much appreciated.

For my snow project I want to combine two terrains. These terrains are pretty similar. The resulting terrain needs to contain the elevations which are highest (or lowest).

My problem is to reconstruct the terrain once I have determined the final elevation. Please refer to screen shot. What do I need to put at the question mark to rebuild the terrain using the elevations that come out of the conditional scalar?

Thanks for your help.


try Create Function - Convert - Build Vector/ Build Colour

Kevin.

AM.

[Alfamike]

Hi Kevin,

Thanks, but I still haven't figured how to get from a reconstructed vector (build vector function) to a terrain.

Below is what I've got, but no fun there yet.

AM.

[Matt]

The Merge Shader allows you to combine two shaders according to the highest altitude. Plug the first fractal into the Merge Shader's "Input node" plug, and the second fractal into the "Shader A" plug. Then in the Merge Shader settings set the Choose by Altitude mode to "Highest (raise)". Leave all other settings at their defaults (Mix to A = 0.5, no mix controller).

You can even colour each shader branch differently and the colours will be merged according to whichever branch creates the highest altitude, as long as you don't override them with other shaders further down of course.

Matt

[Alfamike]

Thanks Matt,

I looked at the Merge shader before but played around with the settings too much and got lost in it.

AM.

[Alfamike]

Hello there, anybody,

Just been puzzling through the embossed snow as posted a while back by Lucio and others. I understand what is supposed to happen but have great difficulties laterally displacing the edges of the snow. All they do is show up as vertical walls, no matter what I try for slope fuzzyness, displacement offset or multiplier.

I looked at some other tgd of a glacier and some of Seth93's tgd's but do not get anywhere with my trials.

I've gone from using a fractal terrain to a heightfield thinking that would take away the sides of the embossed snow from 90 degrees to a less steeper angle making it easier for TG to work on the lateral displacement, but to no avail. Other users don't seem to have this problem.

How much does this embossed effect depend on the terrain, 'cause I have tried various types terrains.

Any suggestions would be much appreciated.

AM.

PS: please refer to attached TGD

************

Just tried to "twist 'n sheer" the vertical sides of the embossed snow, and tried "outcrop 'n strata"-ing them before doing the lateral displacement. No luck so far.