Author Topic: Image map shader over terrain: can it glow? And if so, how?  (Read 1068 times)

Offline dduane

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Image map shader over terrain: can it glow? And if so, how?
« on: August 15, 2016, 10:41:34 PM »
Hi folks! A strange-ish question here --

For a new book cover I need to flow a complicated image full of symbols and whatnot over terrain. By way of testing how this might look, I dropped an image map shader over the default terrain and loaded a test image into it. Moved it around a bit, repeated it in X and Y: fine. So far so good. (You can see my scratch image attached.)

Then I played with the lighting a bit (hanging a planet up over the high ground and leaving the enviro turned up to about 5 for the moment) and realized that for best results on the figures that are going to be positioned on/in this landscape, I need the lettering-or-whatever on the surface to be glowing. Can anyone suggest a way to do this? The image map shader unfortunately seems to lack the luminosity tab I'd have normally gone for to try to produce this effect. I assume this means I'm going to have to use some other shader to get what I want.

Any thoughts on this? Normally I'd spend hours and hours experimenting until I stumbled over the answer myself, but I'm kind of on the clock on this one and the sooner I can find out what I need to be doing, the better. Help?

Best -- DD
Diane Duane | The Owl Springs Partnership
Co. Wicklow, Ireland

Offline Jokes

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #1 on: August 15, 2016, 11:29:56 PM »
Tried it just now, and the trick seems to be: lay the image map shader over the terrain, then create a surface layer shader farther down the chain and choose "mask by shader" and pick your image map as the mask, and use the luminosity settings on the surface layer. I got my terrain to glow pink where the actual image was white.

I don't know too much about how luminosity works in general (and I'm the opposite of an expert in arranging these nodes), so there might be a flaw in this approach that I'm missing, but hopefully it'll help.

Update: Hmm, so the glow part seems to be working as far as that goes, but I tried putting in a sphere to see how the glow affected other objects in the scene and, as you can see, the answer appears to be "not in the slightest". Doesn't seem ideal for your purposes. But at this point I'm way out of my depth, so I have no idea how to improve on this result.
« Last Edit: August 15, 2016, 11:55:28 PM by Jokes »

Offline Oshyan

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #2 on: August 16, 2016, 12:22:42 AM »
Jokes, is your sphere textured at all, or is it pure black? Also you may need a pretty high Luminosity value for it to really work, and it relies on Global Illumination accuracy, so you may need higher settings there for rendering.

- Oshyan

Offline Jokes

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #3 on: August 16, 2016, 12:36:15 AM »
I'm honestly not entirely sure what colour the sphere is. The sun didn't seem to have any trouble lighting it before I dropped it to the horizon, but I'm not sure whether that indicates that the sphere is lightable or just that the sun is really good at its job. (Have I mentioned I'm out of my depth?)

Selected a different shader for the sphere, incremented some likely-looking numbers in the GI settings, set the luminosity of the glow shader to 10, and here are the results. Seems like we have proof of concept.

Update: Further investigation reveals that it definitely seems to be the GI settings that determine whether the glowing terrain is able to illuminate the sphere. When I forget to use the renderer with the higher Global Illumination detail, the sphere goes lightless no matter what else I play with.
« Last Edit: August 16, 2016, 01:18:17 AM by Jokes »

Offline dduane

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #4 on: August 17, 2016, 09:48:29 PM »
Jokes, thank you so much! I would never have worked this out left to my own devices. (Or it would have taken a looooooong time.)

I'll put a pic of the next stage of the cover up here in a bit -- have to produce the image for the non-test layer tomorrow.  Meanwhile for amusement's sake I leave you with two images produced using Terragen over the last few weeks to advertise the books on Instagram.

Thanks again!  :) -- DD
« Last Edit: August 18, 2016, 10:35:43 AM by dduane »
Diane Duane | The Owl Springs Partnership
Co. Wicklow, Ireland

Offline dduane

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #5 on: August 17, 2016, 09:49:28 PM »
Jokes, is your sphere textured at all, or is it pure black? Also you may need a pretty high Luminosity value for it to really work, and it relies on Global Illumination accuracy, so you may need higher settings there for rendering.

- Oshyan

Oshyan, thanks for the assistance! Much appreciated. :) -- DD
Diane Duane | The Owl Springs Partnership
Co. Wicklow, Ireland

Offline ajcgi

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #6 on: August 18, 2016, 08:58:15 AM »
Intriguing!
GI is annoyingly slow with this sort of thing. I've had to work around it with lights on many occasions. It's fun to play with this kind of thing though.

Offline Jokes

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #7 on: August 18, 2016, 05:11:53 PM »
Happy to help, and good luck with the cover! I love those promos. The beach looks amazing, and the subtle colours on the surface of the comet are gorgeous.

Offline Dune

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #8 on: August 19, 2016, 06:38:28 AM »
Very nice renders, and great beach indeed  ;)
In case you still haven't seen enough of my work: www.ulco-art.nl

Offline dduane

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #9 on: August 19, 2016, 09:28:17 AM »
Very nice renders, and great beach indeed  ;)

(grin) Well, of course it's a great beach, it's yours! ...I used it again the other day in yet another render featuring our local Alien Anime Prince and his Earth-native associate: attached below. (ETA: Just realizing I already attached this to the original post. OH WELL.) (eyeroll)

The rock surface used in the "Riding the comet" one, though, is Domdib's hero rock from over here:  http://forums.planetside.co.uk/index.php?topic=8668.0

...A lovely thing... I just plugged it in, "drove" to where its terrain drops off a bit, and dropped the character in there (after shaping him to fit, which took a day or so...)

This is one of the joys of Terragen. It allows you both to be creative and to stand on the shoulders of giants.  ;)

Best -- DD
« Last Edit: August 19, 2016, 09:33:51 AM by dduane »
Diane Duane | The Owl Springs Partnership
Co. Wicklow, Ireland

Offline Dune

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #10 on: August 19, 2016, 01:16:22 PM »
I recognized it  ;) Serves a very nice purpose here.
In case you still haven't seen enough of my work: www.ulco-art.nl

Offline dduane

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #11 on: August 19, 2016, 03:03:04 PM »
So things continue to develop.

I was thinking of overlaying a "spell diagram" on the terrain that would have involved a lot of text and geometrical design, and found myself thinking that (a) this was boring and (b) this wasn't going to be particularly striking graphically -- especially for a book cover, a situation where when you've uploaded the image to Amazon, people will wind up making the buy/no-buy decision guided by an image that may be not much bigger than a postage stamp.

Without warning something occurred to me. Over on my Flickr (https://www.flickr.com/photos/dianeduane/) there are a lot of fractal images produced by an iPad app called Fractile + (no longer available, unfortunately: a shame, because it produces beautiful results and gives wonderful color control). I thought "Well, instead of this diagram, which isn't going to look like much and is going to be a lot of work to produce anyway, why not use one of these fractals?" So I grabbed one and tossed it into my original .tgd instead of the test pattern that had been there. You can see it below.

I then tested it with the masking layer, which worked fine (thanks Jokes!). (Slightly different positioning / angle on the one below as I started playing with the shader image's scale and position.)

So now I can foresee how this workflow is going to go, I think. One render without the character but with the original fractal graphic in place, so as to preserve the colors. One render with the character so as to catch the glow. Then the two will get combined. There may be a third render if that planet acts badly because of differing settings between the first two: we'll see how that goes. 

More as it happens.  :)  -- DD
« Last Edit: August 19, 2016, 03:05:37 PM by dduane »
Diane Duane | The Owl Springs Partnership
Co. Wicklow, Ireland

Offline Jokes

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #12 on: August 20, 2016, 01:09:53 AM »
Wow, that is an utterly gorgeous fractal! I love it!

Online bobbystahr

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #13 on: August 20, 2016, 03:13:19 AM »
Wow, that is an utterly gorgeous fractal! I love it!

ain't it just eh...
something borrowed,
something Blue.
Ring out the Old.
Bring in the New

bobbystahr

Offline dduane

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Re: Image map shader over terrain: can it glow? And if so, how?
« Reply #14 on: November 03, 2016, 12:48:21 PM »
So it's been a while since I posted about this, Let me show everybody the final result.

After a lot of going back and forth with the render, I realized I had a problem with the fractal: it kept coming up blurry in the foreground of the image, which was a problem when the lizard/wizard in the foreground was also sharp and clear.

I tried a ton of settings and couldn't get good foreground results with the fractal no matter what I did. As time was getting tight, I cut my losses and did one final render in which (while assembling everything in Corel PhotoPaint) I then masked out the near-landscape part of the fractal while leaving it in place in the distance. After that I took the raw fractal file, "tilted" it for perspective purposes, and dropped it on top of the render. Finally the lizard/wizard character got added on top. The results you can see below.

This is a process I'm going to come back to at a later date to see if I can iron out the difficulty with sharp foreground rendering of an image map. But meanwhile I just wanted to thank everybody who helped with this: I'd never have been able to get as far with it as quickly as I did without you folks. :)

And now on to a different question. :) (In a different thread.)

--DD
Diane Duane | The Owl Springs Partnership
Co. Wicklow, Ireland

 

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