Martian plains

[Martin]

Hi everyone.
I'm working on a Martian landscape.
I was almost finished, I just wanted to make the rocks more detailed and controlled, when I realized I don't know how to use more than one displace maps on a fake stone layer.So I decided to work and experiment on the rocks, little stones and bigger boulders on a separate tgd file.
On the base Mars rendering you can see that my rocks are strange, no displace sideways , and kind of sunk in the sand.
Does it need a compute normal before the fake stones node? (it has a small sand dune displacement layer before the fake stones node, and a big sand dunes displacement layer before that in the shader nodes)
The usual way I add fake stones is a surface shader with fractal breakup and height etc distribution, then a child layer fake stones shader. But it didn't work quite well this time so I switched off the fractal break up and used the masking node on the fake stones shader(and mask by stone density ) But I have a problem. I can see the terrain base colours  on the boulders. It's suppose to be very dark grey and reddish, yet its reddish and brigth grey.No idea why. The mask fractal breakup is a soft noise, with the smallest scale 3 times as big as the biggest boulder, and with negative offset(screenshot attached). The distribution looks fine but I have problems with the textures. I also used the merge shader two times there to give the boulders 3 displace maps . The mix is displace only. But I find it hard to control the displacement this way, my results are way off.
What should I do differently ?
(I attached one of the ref pics too, a Curiosity photo-)


(I realized this post should probably be in the Image sharing forum. Is there a way to move it there?)

[Dune]

Welcome to the forum, first of all. You posted in the right section, as it's a problem, not only showing what you made.
The rocks need a compute terrain, and preferably smoothing enabled in the surface layer containing the stones, then you'll see the stones getting sideways displacement and more of their own color. For a bit more sideways displacement, you can also try a very small offset in the stone displacement (not too much!).
But smoothing checked sometimes has implications on the terrain (smoothing unwantedly), so I sometimes use just a 'Tex from XYZ' shader before the stones. You might want to experiment with that.
These referenced stones look like they can be made with larger stones with smaller stones attached and some tiny fractal to displace further, so in line, not parallel. Did you find rocks/stones on the forum that you can study for the setup? Another thing is that the breakup shader might give strange artifacts also when using as a mask, I always use a power fractal for distribution, with increased smallest size, and no warp or distort by normal.
I hope this helps a bit.

[bobbystahr]

Also in the presets download from planetside there's a very handy stones .tcg that is great to build off of. It demonstrates a very cool logical network for many stone sizes.

[Martin]

Welcome to the forum, first of all. You posted in the right section, as it's a problem, not only showing what you made.
The rocks need a compute terrain, and preferably smoothing enabled in the surface layer containing the stones, then you'll see the stones getting sideways displacement and more of their own color. For a bit more sideways displacement, you can also try a very small offset in the stone displacement (not too much!).
But smoothing checked sometimes has implications on the terrain (smoothing unwantedly), so I sometimes use just a 'Tex from XYZ' shader before the stones. You might want to experiment with that.
These referenced stones look like they can be made with larger stones with smaller stones attached and some tiny fractal to displace further, so in line, not parallel. Did you find rocks/stones on the forum that you can study for the setup? Another thing is that the breakup shader might give strange artifacts also when using as a mask, I always use a power fractal for distribution, with increased smallest size, and no warp or distort by normal.
I hope this helps a bit.

Thanks. I feel dumb, after writing a long response how the compute terrain- smoothing thing didn't work , I noticed I left the distort funtcion on on the mask fractal. Also I changed the merge displace mix mode to "add" and it look much better now. Thanks. It was my fault after all!

[Martin]

Also in the presets download from planetside there's a very handy stones .tcg that is great to build off of. It demonstrates a very cool logical network for many stone sizes.

I checked one a few days ago, but it only had smaller stones, but with an interesting node network. I'll check the forum for more!

[bobbystahr]

Also in the presets download from planetside there's a very handy stones .tcg that is great to build off of. It demonstrates a very cool logical network for many stone sizes.

I checked one a few days ago, but it only had smaller stones, but with an interesting node network. I'll check the forum for more!

My point was they are a great starting point...just go into the network and mess around with the FS sizes. The network is only 3 stones but you can duplicate it and merge them together, and of import, notice how they are dispersed coloured. There's a static tutorial on stones and their colouring/dispersal in that clip if you investigate it. All the .tgc files in fact I find to most instructive in how to do stuff in TG, one reason I'm certain they're there and if it wasn't a main intent, it certainly has been serving me thus.

[Martin]

Also in the presets download from planetside there's a very handy stones .tcg that is great to build off of. It demonstrates a very cool logical network for many stone sizes.

I checked one a few days ago, but it only had smaller stones, but with an interesting node network. I'll check the forum for more!

My point was they are a great starting point...just go into the network and mess around with the FS sizes. The network is only 3 stones but you can duplicate it and merge them together, and of import, notice how they are dispersed coloured. There's a static tutorial on stones and their colouring/dispersal in that clip if you investigate it. All the .tgc files in fact I find to most instructive in how to do stuff in TG, one reason I'm certain they're there and if it wasn't a main intent, it certainly has been serving me thus.

Yeah, I know, and I checked one- and played with the settings and notes, but those stones had only one small displace attached to them.But I'll look through  the forum to find more rock-tgd-s or clip files!

(after checking a dozen of tgd files, well I have to say I'm amazed by the complexity of a few of those node networks. And I thought I'm getting better at it after using it for a few years.  The use of the get texture coordinates function and using scalars etc are still muddy for me. But it was useful, at least I got a solution for my martian rocks problem. )

[Dune]

Good to hear that. Do share the result, if you want.

[bobbystahr]

What Dune said...we're a curious lot here.

[WAS]

The form may be hard to make but try this function for your basic cracks on the rocks surface.

[Martin]

Sorry, I'm freelancing , so I had a lot of work to do in the past few days so I can pay my rent. I'll try to finish that Martian landscape next week.
Also I will sort my terragen renders I've made in the past few years and post some in the picture share forum.
Sadly I can only work on a laptop right now, not a slow one but still it's time consuming to get things right with terragen or any 3d modelling-rendering software really.

[WAS]

Sorry, I'm freelancing , so I had a lot of work to do in the past few days so I can pay my rent. I'll try to finish that Martian landscape next week.
Also I will sort my terragen renders I've made in the past few years and post some in the picture share forum.
Sadly I can only work on a laptop right now, not a slow one but still it's time consuming to get things right with terragen or any 3d modelling-rendering software really.

I'm on a old Xeon server, so I know the feeling. While rendering itself is not too bad, functionality of Terragen itself suffers greatly.