Gradient Maps (Feat Req)

Started by WAS, August 10, 2019, 04:27:41 PM

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WAS

I'm wondering if in a future release we could get a Gradient Map node for colour shading? I notice a lot of other programs have this based on Y and I think it would be a very quick and easy base to add in TG for defining colours for a whole terrain based on height and gradient dispersion. Currently, I'm not sure how to achieve this but play with surface layer which isn't very fun and a lot of work, especially when you start incorporating more colour variations.

I'm not sure how hard it to add a gradient editor to TG and incorporate it but it would be awesome. I've tried to do something similar with Get Altitude but I couldn't figure it out, and I feel it'd be just about as much working adding/removing node sets to add/remove colours at defined alts.

I believe it would help with quickly starting a colour base for normal scenes, but especially on global levels where Terragen really shines (imo compared to other software doing planets).

Oshyan

This has been requested before but somehow wasn't in our issue tracker. I've just added it to the tracker so hopefully it will be possible in the future.

- Oshyan

Dune

Sounds nice, but don't we already have that (very flexible) functionality? Or do you mean something different?

WAS

#3
Quote from: Dune on August 11, 2019, 02:17:16 AMSounds nice, but don't we already have that (very flexible) functionality? Or do you mean something different?
I mean it seems your showing why explained it's a hassle....you can also just hse a surface layer as one node with mins and maxes. What if you have dozens of colours like used in other programs for great variation, repetition, etc. I'm specifically trying to cut out all the node work that discourages Terragen's use. We need much more out of the box nodes like this imo. I don't want to spend time setting up all that nonsense just to have base colouring. 😂

I'm not sure if you read the original post but I am trying to cut out all the unnecessary node work for something so simple and should be a basic feature.

Also some of those examples are nice, but seem to lack control, and when introducing tons of colours is going to be a mess and hard to work with. They're cool though, useful for other stuff perhaps. in a simpler way.

Dune

Still I don't understand, if you have dozens of colors, can you use only one 'gradient node'? Or need dozens of them too? You might as wll use a surface shader then. And what control? So, you're asking for a gradient node with some controls? But what controls?
I guess I just miss the point of specific node you've requested, but I look forward to having it  ;)

WAS

#5
Quote from: Dune on August 11, 2019, 03:19:22 AMStill I don't understand, if you have dozens of colors, can you use only one 'gradient node'? Or need dozens of them too? You might as wll use a surface shader then. And what control? So, you're asking for a gradient node with some controls? But what controls?
I guess I just miss the point of specific node you've requested, but I look forward to having it  ;)
Gradient editors don't really have limits beyond slider space for slider points. Like im Photoshop you can have some pretty complex gradient maps based on 100% slider. Soo 100 points. Not including 100 for alpha.

WAS

You can test this right now in Photoshop or GIMP quickly with a heightmap of some terrain and a gradient map.

Dune

I'm not fully awake yet, but I still don't grasp what kind of node a gradient node would be; I can only see it as a simple white to black based on Y or altitude (hence a surface/distribution shader with altitude control). But I'll await the node  :P

WAS

#8
Maybe a visual example will show you. Here is a quick example in 2D

In this gradient bar, the positions (points) are 0 - 100. So 100 points. There is also second bar for adding alpha/opacity to areas as well for a total of 200 points, 100 in RGB/Whatever and 100 for alpha data.

The same kinda 0 being low and 1 being high logic is used in Photoshops gradient map.

The smoothness slider contracts and condenses the gradient towards the center, stretching the further most outside colours.

Dune

Is that what you mean, a variable slider with points to set and slide at will (like in the PS gradient map) to give you a vertical set of greys with variable hard and soft edges? That would indeed be handy. I now sometimes use an image map made that way, though a mix of XZ stretched perlin also works, but is far less flexibly handled.

WAS

#10
Yeah basically exactly that. I've seen the same sort of deal selectors in open source, and closed source apps, so must be examples available (I haven't looked).

And mixing gradient maps together, even with just two passes can give you some pretty nice results as seen below. Second gradient map is multiplied at 75% opacity. So in TG multiply shader and surface layers coverage.

(not my maps just grabbed form Google as an example. This is Ireland)

I imagine the transitions of colour would even work better in Terragen, as well as much more space to work with so not as super sensitive. Matt mentioned PS works off of gamma, which would explain the weird colour burning and colour collision you have to fight, which is even seen in this gradiented image. But with fuzzy-zones and breakup in TG this could be very, very powerful!

Dune

Great. Looking forward to that one then!