Contrast/gamma/offset on displacement noise?

[cubic]

How can I go about running some basic image operations such as contrast, gamma, brightness etc on displacement noise.  I can obviously do this on color noise, it even has basic contrast and offset options, but the displacement noise options are lacking in this area.

I'm most likely missing something obvious here :-)

PS.  This program is DYING for a gradient editor, being able to remap noise into a gradient and remap it is the bees knees.

[Tangled-Universe]

Or I'm missing your point here or we're both missing something obvious indeed

When running the image operations - as you call them - on colors then subsequently you're applying these to the displacement as well.
The displacement amplitude and offset are derived from the colors set in the color-tab of the powerfractal.

The displacement roughness and spike limit perhaps too might be seen as an image operation similar to contrast, brightness or gamma.
However, you regulate these primarily via the color tab of the powerfractal.

What do you mean by remapping noise into a gradient? You want for example to apply noise to a certain part and then want to control that using a gradient?
That's present in TG2 and quite simple using a distance shader which gives you a radial and z-depth gradient options.

I hope some of this helps.

Cheers,
Martin

[cubic]

Ah k so any changes to the noise in the color tab also affect the displacement effect of the noise as well?  I'm still not seeing changes to the color tab having any effect on displacements i.e. if I change the color contrast it only affects the color portion...

Sorry, when I say gradient editor I also mean a curve editor.  You would plug your fractal into the curve/gradient node and then remap it there.  Probably the simplest example is the gradient remap tool in photoshop.  It has no visible curves but operates on the same premise.

http://www.photoshopforce.com/tutorials/gradient-map-tool/index.php

I find bezier curves a lot better than pure gradients with keys though.

[Tangled-Universe]

Maybe it is a bit better to explain what you want to achieve with these kind of operations, because I think I know what you want, but I'm also not sure if you really understand what TG can do at this stage.

Basically, for manipulating displacements in TG you only have to manipulate "color".
If you for example add displacement of 1m to a fractal then the white part will be displaced 1m and the black part 0m and anything in between white and black will be between 1m and 0m. So a lot of those operations in the color tab and some in the displacement tab effect like image operators.

If you want to curve-like things then there aren't many options I believe. For example there are bias scalars for color-adjustments, but also a color-adjust shader for increasing/decreasing black/white points and gamma.

The node functions might give you even more options, but that's honestly out of my scope.

[cubic]

Basically, for manipulating displacements in TG you only have to manipulate "color".
If you for example add displacement of 1m to a fractal then the white part will be displaced 1m and the black part 0m and anything in between white and black will be between 1m and 0m. So a lot of those operations in the color tab and some in the displacement tab effect like image operators.

Here's what I'm seeing.  I add a displacement power fractal in the Terrain tab or in the nodal view.  I adjust all my scale settings, everything looks good.  I'm not even using it's high and low colors, those are turned off.  

So at this point the only way to adjust the displacement effect of the noise is under the displacement tab in the power fractal.  All the controls under the color tab are having NO effect at all on my displacements.  Which is a shame since I'd really love to be able to use the contrast controls.

edit:  okay, I'm trying different methods now, I've plugged a power fractal into a displacement node and now the displacement node seems to be using the hi and low colors whereas simply checking displacement in the power fractal doesn't... I'm running into some of these oddities with the workflow that aren't explained properly anywhere.  I suppose I'll just have to figure it out :-)/

[Tangled-Universe]

All the controls under the color tab are having NO effect at all on my displacements.  Which is a shame since I'd really love to be able to use the contrast controls.

Are you really sure about this? If so then it would be strange that it works using a displacement shader since that uses the color-information, which you in fact had turned off.
I never turn off my colors, no need to, but as far as I remember the displacement-function of the powerfractal does not require colors to be switched on, he still uses them.
I think to be conclusive about this Oshyan or Matt could chime in, I'm a bit confused now honestly. I don't often have these unlogical situations.

Martin

[cubic]

Heh I think we've got our wires crossed a little :-).  You're right that the displacement function of the power fractal doesn't need colors turned on, and that was sort of my issue that I couldn't use the controls under the color tab for displacement.  I've found a way around it though by just plugging the power fractal into an independent displacement shader which is bypassing the power fractals built in one.

[Tangled-Universe]

Ah right, now it starts to make more sense to me as well
I'm glad I could have been at least a bit of help

Given your name, are you Dutch? Or just a Dutch-named Canadian, hence you're working for The Embassy VFX.
I'm curious what such a studio would like to do with TG2

Cheers,
Martin

[cubic]

Ah right, now it starts to make more sense to me as well
I'm glad I could have been at least a bit of help

Given your name, are you Dutch? Or just a dutch-named Canadian, hence you're working for The Embassey VFX.
I'm curious what such a studio would like to do with TG2

Cheers,
Martin

My Grandfather and my father were Dutch but I'm a Canadian by birth :-)

I'm evaluating TG2 for use in projects that require computer generated landscapes.  For now we're thinking it would be used mainly for background effects i.e. skies and mountains for matte paintings or higher altitude aerial renders.

I've also spoken to Robert Nederhorst a few times and he sort of sold me on TG2.

So far I can see that there's a LOT of power here but there's a distinct lack of artist friendly tools/compounds especially for displacements.  Items such as the strata shader are a step in the right direction though, as are the alpine shader, fake rocks, populator etc etc.  Those sorts of tools make the process much more focused on visual as opposed to technical creativity.

I may jump back into World Machine to generate some wider area displacement maps and see what I can do with those. I get the feeling I'm attempting a little too much to start and should try and make it easier on myself.  I looked at the TG2 gallery and figured it couldn't be that hard to get results like that, silly me :-)

[Tangled-Universe]

Ah right, now it starts to make more sense to me as well
I'm glad I could have been at least a bit of help

Given your name, are you Dutch? Or just a dutch-named Canadian, hence you're working for The Embassey VFX.
I'm curious what such a studio would like to do with TG2

Cheers,
Martin

My Grandfather and my father were Dutch but I'm a Canadian by birth :-)

I'm evaluating TG2 for use in projects that require computer generated landscapes.  For now we're thinking it would be used mainly for background effects i.e. skies and mountains for matte paintings or higher altitude aerial renders.

I've also spoken to Robert Nederhorst a few times and he sort of sold me on TG2.

So far I can see that there's a LOT of power here but there's a distinct lack of artist friendly tools/compounds especially for displacements.  Items such as the strata shader are a step in the right direction though, as are the alpine shader, fake rocks, populator etc etc.  Those sorts of tools make the process much more focused on visual as opposed to technical creativity.

I may jump back into World Machine to generate some wider area displacement maps and see what I can do with those. I get the feeling I'm attempting a little too much to start and should try and make it easier on myself.  I looked at the TG2 gallery and figured it couldn't be that hard to get results like that, silly me :-)

Well, if you look for an experienced TG'er to do some background renders for matte

Ghehe, it's indeed not that simple. On CGTalk and other professional forums they still think TG2 is a click and render program which it really isn't, so I'm  glad you reckon it.
I wouldn't give up to soon using/understanding TG's procedurals, though using WM2 as a base for your work is a good start since it comes with good examples and documentation, that's something Planetside still is working on. Also, heightfields are generally a bit faster than a procedural terrain (depends on complexity of course) but of course lack the amount of detail and beauty which comes with TG2's fractal displacements.

I'm not surprised Robert persuaded you to start using TG2. He probably knows Matt from DD I think and he worked on some titles which used TG-like software (Engen I think) like Stealth, Day after tomorrow and Star Trek, but that's probably no news for you

Anyhow, welcome to the forums and if you have any questions just ask here. Lots of helpful people
Posting your images/WIPs is probably the best and fastest way to get your grips.

Cheers,
Martin

[Elegy]

I'm afraid I haven't read the replies so I apologise if what I'm about to say has been repeated.

The displacement of power fractals is not affected by any changes you make in the 'Colour' tab but the 'Displacement' tab has two rather obvious analogous options.

'Colour offset' is 'Displacement offset'.
'Colour roughness' is 'Displacement roughness'.

If you wish to have more control over the displacement options, you can always plug in the power fractal into a displacement shader. The displacement shader uses colour information to drive displacement. If you do this, you can use the 'Colour' tab to change the colour information, which will affect the displacement.

You can also add colour functions in between the power fractal and the displacement shader. Of particular note is the 'Colour adjust shader' which allows you to modify the brightness and the contrast with the first tab and the gamma with the second tab.

If you do use the displacement shader in this way, I strongly recommend lowering the colour roughness: 5 is far too high for most displacements. I usually use a value of around 1.75.

[cubic]

If you wish to have more control over the displacement options, you can always plug in the power fractal into a displacement shader. The displacement shader uses colour information to drive displacement. If you do this, you can use the 'Colour' tab to change the colour information, which will affect the displacement.

You can also add colour functions in between the power fractal and the displacement shader. Of particular note is the 'Colour adjust shader' which allows you to modify the brightness and the contrast with the first tab and the gamma with the second tab.

If you do use the displacement shader in this way, I strongly recommend lowering the colour roughness: 5 is far too high for most displacements. I usually use a value of around 1.75.

That's exactly what I was looking for ty very much!  I managed to figure out that plugging a power fractal into a displacement node allowed for usage of the color info myself, but the color adjust shader I did not know about and it seems to be just what I need.

Cheers!