Localizing Strata/Outcrops

Started by choronr, December 15, 2007, 03:28:39 PM

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choronr

When applying Strata/Outcrops, I've tried to localize the effect to a specific area rather than having it affect the terrain globally by using a distribution shader; however, this does not work. Any thoughts on this subject?

Bob

Oshyan

It seems to work fine here. Can you tell us more about your setup, show a network screenshot or even share a .tgd?

- Oshyan

choronr

Thanks Oshyan for getting back to me. Attached are the .tgd files for your review. I've disabled a number of nodes that are unimportant to this issue.

Bob

joshbakr

Quote from: choronr on December 15, 2007, 03:28:39 PM
When applying Strata/Outcrops, I've tried to localize the effect to a specific area rather than having it affect the terrain globally by using a distribution shader; however, this does not work. Any thoughts on this subject?

Bob

Hi Bob,

Try putting the Distribution Shader (or use a Surface Shader) where you have the Strata Shader then attach the Strata Shader as a Child to the distribution shader. In other words just switch there places.  Works for me.

choronr

Thanks Josh; we'll give it a try.

choronr

Josh, I tried what you have suggested; but, the strata issue remains the same ...no strata.

joshbakr

Quote from: choronr on December 15, 2007, 06:11:44 PM
Josh, I tried what you have suggested; but, the strata issue remains the same ...no strata.

I just made some changes like: Replaced the distribution shader with a surface shader and colored it bright pink so you can see where it's going. I also lowered the fuzzy zone on the max altitude to 40 and set a min slope range. It shows up on my end now. In the surface layer you can disable the apply color or change the pink to your colors. see attached tgd.

Note: I added bz to the end of the tgd name so you can identify it easier.

choronr

Thanks again Josh; you've been a great help. I will try this soon.

choronr

Thanks Josh; it worked!! Now I have to work on the strata settings ...really appreciate it friend!

Oshyan

It seems to be working fine in your setup, it's just that your distribution shader severely limits where it will show up. With a 200 meter maximum altitude and 100 meter fuzzy zone, unless your terrain (which I don't have) has a very low average altitude range, you're just not going to see much. Using the included terrain (re-enabled and generated) you see virtually no strata with your current distribution settings, but if you adjust the settings it shows up appropriately. So in other words your setup is fine, your constraints are the problem. Just adjust the specific constraints and you should get better results.

- Oshyan

choronr

Thanks Oshyan for getting back to me. The 512 DEM terrain I used here is 'Monument Valley' which I tried sending to you; but, your server wouldn't accept it. The terrain is rather flat except for the landforms which rise abruptly to almost 90 degrees. In the case of the famous 'Mittens', there are talus erosion grading surrounding both the right and left Mittens. This is where the strata should appear. I need to experiment with the settings and try to achieve what we see in reality.

Two other issues exist; namely, I cannot duplicate the actual appearance of the Mittens. Each Mitten displays a space between the thumb and the fingers. Apparently there are some displacements I need to adjust in order for the spaces on the Mittens to appear; but, I'm not sure what I should be adjusting; and, how much the adjustments should be ...some experimentation needed here.

The other issue is that of trying to get the vegetation to appear properly. I have three populations in the file. I've tried many, many different settings trying to get the plants to appear on the lowest surfaces. In most cases, the vegetation always seems to appear much higher up than normal.

Oshyan, I would appreciate your input on these issues.

Oshyan

If the spaces on the "mittens" are not present in the original DEM file (which they may not be, due to DEM resolution) then they will be extremely difficult to reproduce in TG2. To see whether they are there in the original data you want to load the .ter up in a new, blank project, with no other displacement applied, then turn off the "fractal detail" (Fractal Detail tab in the Heightfield Shader). If you see the gaps then they are present in the DEM data and if you keep the additional displacement to a minimum they should be maintained. If they're not there in the original data, I would sooner try editing the heightfield in another program such as Wilbur or Leveller than try to create such a specific shape in TG2.

With the populations, I would again start by going "back to basics". Try to apply a single population to the basic terrain, without surfacing or additional displacements. If this works then go from there, one change at a time, toward your goal. As soon as you make a change that messes things up, you know why it's not working and you can either experiment with it further to address it, or report the problem and see if others can help. More specifically, in your .tgd I see that several of the populations have a density shader with an extremely low coverage. This will produce a very low probability of seeing any objects. I would suggest not using the same density shader as your fake stones since the density functions work a bit differently for populations. Again, start with full coverage, then apply your density shader and use high values above the intended range first, to make sure you can still see your objects, then slowly dial it down until you either get the coverage you want, or you lose the objects entirely. If the objects disappear, back off on the settings a bit and try again. There is often a lot of fine-tuning necessary when working with very specific needs for your scene, especially with a small range of altitude as you mentioned was present in your original terrain. There's really nothing that will let you avoid the need for experimentation to get the exact result you want.

- Oshyan

choronr

Your reply and the time you spent on this is appreciated Oshyan. I will work on these issues and see if I can resolve them. Thank you.

schmeerlap

I am currently working on a scene that has rugged mountains in the  background (I used the Strata and Outcrops shader to help isolate them and thrust them upwards). My foreground is a kind of smooth grassy knoll with trees. I separated the two types of terrain features (rugged and smooth) using a Distance Shader applied to the foreground Fractal Displacement as a  Blend Shader (Near from Render Camera) and I have successfully pushed back the rugged terrain into the background. Have you tried using a Distance Shader. Maybe it is difficult applied to a Strata/Outcrops Shader because of the massive diplacements involved. And as I'm writing this I can't recall if you can apply an X-Z reference point in a Distance Shader to centre the localisation from, rather than from camera.
I hope I realise I don't exist before I apparently die.

choronr

Quote from: schmeerlap on December 28, 2007, 10:21:36 AM
I am currently working on a scene that has rugged mountains in the  background (I used the Strata and Outcrops shader to help isolate them and thrust them upwards). My foreground is a kind of smooth grassy knoll with trees. I separated the two types of terrain features (rugged and smooth) using a Distance Shader applied to the foreground Fractal Displacement as a  Blend Shader (Near from Render Camera) and I have successfully pushed back the rugged terrain into the background. Have you tried using a Distance Shader. Maybe it is difficult applied to a Strata/Outcrops Shader because of the massive diplacements involved. And as I'm writing this I can't recall if you can apply an X-Z reference point in a Distance Shader to centre the localisation from, rather than from camera.

Thank you for these suggestions. Since this original post, I have discarded the project due to the poor resolution of the DEM file I was using; but, I would like to try your idea on another project.