Author Topic: Newb question - compute nodes  (Read 521 times)

Offline ruddiger52

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Newb question - compute nodes
« on: April 02, 2018, 11:00:55 PM »
I am trying to displace a plane with a fractal so I can export the geo and use as a set piece elsewhere.

I create a plane object and then try to assign a terrain.  I get this error...

"You must have a Compute node attached to the planet or object"

I can not figure out how to do this despite scouring the internet.

any help is appreciated. 

Thanks

Offline WASasquatch

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Re: Newb question - compute nodes
« Reply #1 on: April 02, 2018, 11:40:26 PM »
Unfortunately, geometry will not be saved with your plane. Just the text-based settings for Terragen to interpret.

To answer your question though, the Computer Normal and Compute Terrain nodes are location in Right Click [Node Network] -> Create Shader -> Other Shader
« Last Edit: April 02, 2018, 11:43:02 PM by WASasquatch »
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Offline ruddiger52

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Re: Newb question - compute nodes
« Reply #2 on: April 02, 2018, 11:49:06 PM »
Is there a way to connect the compute node so the geo displacement will be visible in the viewport? As it is on launch of a new scene?

Offline WASasquatch

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Re: Newb question - compute nodes
« Reply #3 on: April 03, 2018, 12:01:37 AM »
Is there a way to connect the compute node so the geo displacement will be visible in the viewport? As it is on launch of a new scene?

I don't believe you actually technically need a Compute Normal or Terrain unless you're specifically doing shader work below your displacement which needs computation of the displacement. But for learning purposes I have attached a TGD containing two types of planes, one with a compute, and the other without.

Notice the compute normal, set to a patch size of 5 meters, changes the displacements look, which in some cases can ruin the look of your unique settings.
« Last Edit: April 03, 2018, 12:03:40 AM by WASasquatch »
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Offline Matt

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Re: Newb question - compute nodes
« Reply #4 on: April 03, 2018, 02:43:19 AM »
If you look at the default project you'll see that there is a node called "Compute Terrain". This needs to be somewhere in your project for some parts of the UI to know how to separate terrain from other surface shaders and to know where things should be inserted when you use the "Add Terrain" button. If you don't have this in your project then you can either copy this from the default project or create a new one. Usually you'd do this with the Node Network. One way to do this is with the Quick Node Palette: Click in the Node Network, hit the N key or the Tab key to open the Quick Node Palette, start typing "Compute Terrain", double-click the Compute Terrain item or hit Enter if it's already selected.

You can use this with a Plane. Open the properties for the Plane. Look for the "Surface shader" parameter. Click on the "+" button, and in the menu select "Assign Shader" and select the Compute Terrain node that you previously created.

If this is the only Compute Terrain node in the project, then the "Add Terrain" button will automatically add terrain shaders above this Compute Terrain node.

Matt
« Last Edit: April 03, 2018, 02:53:10 AM by Matt »
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Offline Matt

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Re: Newb question - compute nodes
« Reply #5 on: April 03, 2018, 02:54:41 AM »
Is there a way to connect the compute node so the geo displacement will be visible in the viewport? As it is on launch of a new scene?

Displacement should be visible in the 3D Preview regardless of whether or not you have a Compute Terrain node. If it's not, then the displacement isn't properly assigned to the plane. But if you follow the steps above, any terrains you add with the "Add Terrain" button after that should become part of the chain of shaders assigned to the plane, so it should work.

Matt
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Offline Dune

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Re: Newb question - compute nodes
« Reply #6 on: April 03, 2018, 05:34:07 AM »
And if you select the compute terrain already present in default scene and hit CTRL+D you have a copy.

Offline ruddiger52

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Re: Newb question - compute nodes
« Reply #7 on: April 03, 2018, 03:48:21 PM »
Digging into this now.   Thank you for all the help everyone

Offline ruddiger52

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Re: Newb question - compute nodes
« Reply #8 on: April 03, 2018, 04:40:20 PM »
ok so I am able to get my plane displaced with a power fractal. (Thank you)  but now when I try to add anything to it ..like a surface layer.....terragen just crashes.  I have tried multiple times with different shaders

Offline luvsmuzik

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Re: Newb question - compute nodes
« Reply #9 on: April 03, 2018, 07:38:02 PM »
A default new scene in Terragen is a terrain power fractal (These are your hills and mountains) (feature 5000, displace 2000, seed 119)masked with a simple shape shader. The flat surface of the default new scene is that Simple Shape Shader, It is positioned at 0 0 0. This scene is default material set in Base Colors in Shaders. You can displace Base Colors but this will effect the flat surface of the Simple Shape as well as remaining terrain.

In shaders, you can add surface layers to add color (often with a powerfractal)  displace(usually a power fractal), limit altitude, and slope. The child of a surface layer can add more color, fake stones, etc.

If you prefer a scene with no hills or mountains.....lower the displacement setting in terrain power fractal from 2000 to around 150-200.



Offline Matt

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Re: Newb question - compute nodes
« Reply #10 on: April 05, 2018, 03:05:26 AM »
ok so I am able to get my plane displaced with a power fractal. (Thank you)  but now when I try to add anything to it ..like a surface layer.....terragen just crashes.  I have tried multiple times with different shaders

Without the Planet it crashes. It's not a commonly-used workflow to work without a planet, so you're more likely to run into bugs.

I recommend leaving a Planet node in the project, and have the same set of shaders connected to both the Planet and the Plane. You can disable the Planet so it doesn't show in the preview or in renders.
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Offline luvsmuzik

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Re: Newb question - compute nodes
« Reply #11 on: April 05, 2018, 03:41:01 AM »
ok so I am able to get my plane displaced with a power fractal. (Thank you)  but now when I try to add anything to it ..like a surface layer.....terragen just crashes.  I have tried multiple times with different shaders

Without the Planet it crashes. It's not a commonly-used workflow to work without a planet, so you're more likely to run into bugs.

I recommend leaving a Planet node in the project, and have the same set of shaders connected to both the Planet and the Plane. You can disable the Planet so it doesn't show in the preview or in renders.

So you no longer get the message about....."'you must have a heightfield" right before....terragen has stopped working does its crash?