Frank's Free Edition Road WIP Thread

Started by FrankB, February 24, 2013, 12:34:44 PM

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FrankB

Hi guys,

although I am not going to participate as a contestant, I'd like to create this thread as a mix of a blog, tutorial, my own image development ideas related to the current NWDA image contest. YOU are invited to discuss with me here, as questions, make suggestions etc., so don't be shy.

In particular, I am going to challenge myself and apply exactly the same restrictions that the Terragen 2 Free Edition has: no more than 3 pops, 800 px width max render resolution, Anti Aliasing max 3, and I am determined to create a really photo realistic road scene with it - to the best of my abilities of course.

Now, how will I approach the image challenge? I have a lot of thoughts and even more questions, so I am just going to write them up down below and see if I can progress the thoughts and answer some of the questions I have for this, one by one....

1) I need to figure out where to begin best, so that later on, I don't have to make too many changes because of dependencies. For example, I could start with making the terrain. Or should I start making the road? Or should I first figure out what kind of scene I want to create?

2) AA3 is a tough limitation. Usually such a low AA value will result in not so great looking vegetation. Luckily with Ray trace objects, that's not awful, but something tells me that for a winning image I need smoother edges.

3) Also I want to submit a full HD size final image. I know it's not required, but an 0.8k image isn't even usable as a desktop wall paper :D So that means I have to render multiple images and then stitch them together somehow later. I think I will want to render at least 9 800x600 tiles, which gives me a 2400 x 1800 render. I would then reduce the final image size to full HD and through that get smoother edges, hahahaaaaa!  :o

4) I have never done (3) before, so... Just thinking out loud: when a "regular" render uses maybe 60 degrees FOV for the camera, and I would render 3 tiles horizontal, will I have to reduce the horizontal FOV to 20 degrees each, in order to stitch the images together seamlessly and retain the original 60 degree FOV? I think I will have to do this, but I can solve that later.

5) there are multiple ways on how to create a road. I could launch photoshop or gimp or whatever you prefer and just paint a mask for the street in white color on black background. I would then use that mask as a blend shader in TG2. (If you have no idea how to use such a mask in TG2 please ask and I will do my best to explain.). Second option would be to create a mask right inside Terragen, and for that I see 2 practical possibilities: either I create that road mask through a long and thin simple shape shader, or I create a procedural road.
I think the simple shape shader based road might be most practical for this image.

6) In order to keep things simple, I think I will start with a straight road on a quite smooth base terrain and see where that takes me.

I think I will just start somewhere and I am going to share every step of the way here.

Look on for my next post!
Any thoughts about how you're going to approach this yourself, yet?

So long
Frank

FrankB

I thought I might like a road that leads towards some alpine mountains.
I want to keep things simple and not worry too much about the technology of making a road that would wind with the terrain, so I am using a little trick. Through distance shaders, I ensure that the area near the camera is perfectly flat. In the distance, alps are slowly starting to build up, and beyond the immediate foreground, some rolling hils are displaced downwards, so that the road decends to beyond where I can't see it.
The road itself for now is just a surface shader blended by a streched simple shape shader.

You can check out the simple setup in the attachement.


folder

thanks Frank - following your suggestion i had been looking at photos  of roads in various climates,  and initially had the iidea of a moutain road with a far off alpine peak. that will change as i see now it is somewhat common and plain. my question pertains to your tgd as i am  not familiar with making roads i am using yours as a testbed. how to i keep the road surface clear while placing colour, etc on both sides.  the questiaton really comes down on how to use the simple shape shader. that is where i am really weak

thanks david

FrankB

Quote from: folder on February 24, 2013, 06:43:46 PM
thanks Frank - following your suggestion i had been looking at photos  of roads in various climates,  and initially had the iidea of a moutain road with a far off alpine peak. that will change as i see now it is somewhat common and plain. my question pertains to your tgd as i am  not familiar with making roads i am using yours as a testbed. how to i keep the road surface clear while placing colour, etc on both sides.  the questiaton really comes down on how to use the simple shape shader. that is where i am really weak

thanks david

Hi David,

please still use your initial idea if you wish, I am just playing around and in the meantime have also switched to another idea.
About keeping the road surface clear from other color: ideally your road surface is applied last in the surface shader chain.
Also, you could use the simple shape shader as a blend shader for other surface layers, but invert the blend shader. This way, the surface shader only applies color outside of the road.
Hope this helps. Don't hesitate to ask further questions. :)

Cheers,
Frank

inkydigit

nice one, thanks for the insight and tips, Frank!
:)
Jason

FrankB

Hi guys,

today I would like to shed some light on the tech required to create a winding road, and how procedurally embed the road into a procedural terrain. I have no idea whether this approach works with heightfields, though!

Essentially what you want to do is two things (for starters):
a) turn the straight simple shape shader road into a winding road
b) let a terrain "grow" left and right of the road.

Have a look at the attached tgd. There is a grey group named "Road Mask". Here, a Simple Shape Shader (SSS) creates a quite wide road mask, with very smooth edges.
This mask is then distorted by a redirect shader and a warp shader. THIS makes your road curved in the end! It is important the SSS uses Texture Space, NOT final position. There is a switch in the node dialog for that.

Now that you have that very smooth mask, we run that through a color adjust shader. Play with its values to see what it does, but remember the current values so that you can get back.
This modified mask then goes into the blend shader of a power fractal, which is generating our terrain. We tell the power fractal to invert the road mask blend input, and generate terrain wherever the inverted mask is not black! Because the mask is so smooth, the fractal will produce terrain near the road only very very softly, then as the distance from the middle of the road mask increases, will produce more and stronger displacement. For some reason that I don't understand, you need to disable "Fit blend shader to this" in the power fractal for this to work.

In the surface group, the road mask is fed into another color adjust shader. This color adjust shader manipulates the incoming color until only a very sharp line remains. This way we have a broader level field embedded in the terrain, and in the middle of it a narrow road.

Again, check out the value in the color adjust shader, they are instrumental in making this work.
Also remember, many paths lead to Rome, and this is just one possibility. You can get same and perhaps better results with other methods. Feel free to use this method, or experiment more to come up with your own.

Have fun
Frank

bla bla 2

Et, comme ça par le paint shader, il ne reste cas peindre la route. Tous ça par manuellement.  ;)

And how the paint shader, it remains the case paint the road. All this by manually.  ;)

FrankB

Yes, you could use the paint shader, but I think the result will be inferior, or even really bad. I believe you would have much more control using a tablet/photoshop combination, if you prefer to paint the masks.

Kevin F

Frank, In your first example you used an Alpine Fractal for the procedural terrain, and if you use the bending method from the second example as a blending shader for the Alpine Fractal very weird things happen. The displacement values are far too high for the default Alpine terrain. So question: What determined the values you chose for displacements etc. in the second example?

FrankB

Quote from: Kevin F on February 25, 2013, 05:35:12 PM
Frank, In your first example you used an Alpine Fractal for the procedural terrain, and if you use the bending method from the second example as a blending shader for the Alpine Fractal very weird things happen. The displacement values are far too high for the default Alpine terrain. So question: What determined the values you chose for displacements etc. in the second example?

It does work, but indeed the default values of the alpine are making it difficult. You want to decrease the displacement, add a negative offset, and use a higer scale step to create wider valleys. Check out this node:


<terragen_clip>
   <alpine_fractal_shader_v2
      name = "Alpine fractal shader v2 01"
      gui_use_node_pos = "1"
      gui_node_pos = "-1240 660 0"
      gui_group = ""
      enable = "1"
      input_node = ""
      gui_use_preview_patch_size = "0"
      gui_preview_patch_size = "1000 1000"
      seed = "30485"
      feature_scale = "4000"
      lead-in_octaves = "0"
      lead-in_scale = "4000"
      smallest_scale = "10"
      noise_octaves = "5"
      apply_displacement = "1"
      displacement_amplitude = "1200"
      displacement_offset = "-200"
      displacement_roughness = "1"
      scale_step = "5"
      stretch_factor = "3"
      late_deposition = "0.06125"
      early_deposition = "0.25"
      early_deposition_rate = "2"
      warp_amount = "0.25"
      blend_by_shader = "1"
      blending_shader = "Colour adjust shader 01"
      invert_blendshader = "1"
      >
   </alpine_fractal_shader_v2>
</terragen_clip>

FrankB

here is a render using the alpine and the setting posted above.

FrankB

Alright, so I have to get back to how I am going to finally decide on what I am going to create.
Taking into the account the limitations of the free edition, I will have to settle on something simple, yet something that despite the limitation, plays on the strengths of TG2 and that I can make look incredibly realistic.

I should not write this in public at all, to not inspire Martin or Ulco, although they like me are competing just for fun. Instead I should lead them to believe some false things so that I could gain a proper, unfair competitive advantage  :P

Joking aside, I think I will settle for a quite barren landscape, that is dominated by rock and some sparse and dry vegetation. I know, that's kind of a classic, done a million times by others. Hell, "I" seem to have already done it a million times, but let's not forget by binding myself to the capabilities of the free edition, I have pick what works at the core of TG2 and that doesn't require lots of populations or insane AA.
At the base of it all I will resort to the procedural road from NWDA. It only uses tech that's available in the free edition of TG2, it's versatile, and best of all: it works great, Muahahaha! and saves me time. I will not have a lot of free time in March so I will take this shortcut.

If time permits, I will change the default road setup to make the road look much more worn and abused, so that we get the impression of a long abandoned tarmac road in the middle of a desert.
That's probably not too original, but it doesn't have to. I won't give away too much at is point, but for sure I will add something epic to this setup. In my mind, it's already there ;)

Definitely post YOUR work in progress, too, or maybe just your thoughts about it to begin with.
If you have questions, the NWDA team will be happy to give you a few pointers to get you going, and I am sure so will the other forum members.

Have fun!
Frank

FrankB

So I have been traveling and away from my computer the past few days. Every now and then my mind was still set on making choices for my free edition scene, without being able to try them out.

I am at an airport waiting for a delayed flight, so I have time to write a little journal entry here.

i think i need to have a point of interest along the road, not sure what though. I haven't seen any photo realistic dead tree yet, otherwise it would have been something like that. Perhaps the point of interest could be a rock formation in the midground?  car wreck? Lost zombie? What would you see on highway in the middle of the desert?
Any ideas ?



bla bla 2

Je verrai bien une voiture en abandon bien rouillé, genre tout pourrie.
Et, sinon, pour le tronc mort où des arbres morts, je pourrai le faire avec le logiciel speedtree.
^^


I'll see a car abandoned rusty well, like all rotten.
And if not, where the dead trunk of a dead tree I can do with the software SpeedTree.
^ ^

inkydigit

Roadkill? Hitchhiker? Small creature of any kind?
The possibilities are almost limitless!
J
:)