Newbie help with heightfields/distant mountain range

Started by AdrianB, June 25, 2020, 11:56:10 am

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AdrianB

Hi everyone, new Terragen user here. Thus far I would have to say my 2 weeks of experience with it has been really enjoyable but I am now experiencing some frustrating roadblocks. I am trying to create a distant mountain range to use as a backdrop in a 3D scene but am running into issues.

So far I've managed to create what's in the Mountains.jpg file

This was created using an Alpine fractal. I'd like to know if it's possible to manually get rid of the front hills (outlined in red) because it's hiding the mountain range behind. It seems that there is very little control to be had when using fractal generated landscapes, is this correct?

So I've been trying to get my head around heightfields and how they work in TG. It seems using a heightfield will give me the exact control I'm after, ie a thin mountain range exactly where I want it, but I can't get anything to look remotely like a mountain range at all. I either end up with a completely spikey image or rubbish looking mounds. So going right back to basics to try and understand what's going on I created the heighfield as shown in Heightfield.jpg file and the resulting render in HeightfieldRender.jpg file.

This gives me the shape I would expect but why the bumps? Why is it not smooth? I've tried changing all the shader displacement settings and nothing I change in the terrain displacement tab makes once bit of difference, apart froom height multiplier which just makes it smaller or bigger.

My actual heightfield file is a TIFF file rather than JPG which is just for compression purposes for the forum

Any help would be massively appreciated :-)


Adrian.

WAS

It's not smooth because you are seeing the banding of the TIFF file. If you want it absolutely smooth you'd need to create it in 32bit mode and export as 32bit float TIFF. If PS is in 8bit mode saving as 32bit float or higher won't help as the data just isn't there.

As for the alpine mountains it looks like that hill is directly part of the mountain to the right. The best way to mask it is to mask your mountains inside a Simple Shape Shader.

AdrianB

Thanks, will give a simple shape shader a go. Thanks also for the heads up on TIFF files, had no idea about any of that. I would assume that any heightfield TIFF file should be exported as a 32-bit float for best results?

mhaze

You can also use a painted shader for a more precise mask.

Dune

I never work with heightfields, but as WAS says, with (soft!) simple shapes you can mask in or out whatever you want. Eithe put the alpine as child on a masked surface layer or mask the alpine directly.
A 16-bit tiff will make a huge difference already, and is easier to make in PS, and less heavy.

AdrianB

June 26, 2020, 04:33:23 am #5 Last Edit: June 26, 2020, 05:04:32 am by AdrianB
Hmm, well exporting as 32-bit float means nothing shows up in Terragen at all. I tried a 16 bit TIFF and it's definately smoother.

Thanks for the other suggestions, I will play around - at the moment I have no clue how to use a painted shader or mask a child object. It's great there are more tutorials for TG now (I've been following the Terratuts and GeekAtPlay ones which are really good) but there still seems to be a lack of intermediate/advanced ones.

EDIT: On the tutorial front I just realised there are lots more I can actually buy which seem to cater for more advanced stuff. Great!

Dune

Experimenting, after reading up on the basics of TG, is paramount!

This is how you basically mask a surface shader (with child) by a simple shape. A painted shader can be attached just as the simple shape, but then you can paint on the surface (for any masked color or displacement). Set size of brush and paint.

You best put the bigger displacements before the compute terrain, smaller and colors after compute terrain.

AdrianB

Thank you :-) I think I've been trying to run before I can walk, time to learn as much as I can and as you say, experiment!