Author Topic: So I tried MOLA shader...  (Read 641 times)

Offline N-drju

  • Member
  • *
  • Posts: 791
  • Changes, changes, changes...
So I tried MOLA shader...
« on: October 28, 2016, 05:56:02 AM »
Morning everyone,

I recently downloaded some .img files from this site - http://pds-geosciences.wustl.edu/missions/mgs/megdr.html. I downloaded some files from the meg128 directory. Then, downloaded MEGT files and tried to test one. I made sure that the data set is correct, thus picking the MEGT128 option in the data set drop-down list.

Unfortunately, once I entered the file name nothing happened. And I mean that literally nothing was happening. :P Terragen just froze, and the "busy circle" was indefinitely dancing on the screen. When I checked the memory usage I was also surprised to see that the RAM value was idle - around 2GB. It did not increase even one bit.

I'm not sure if this is actually a bug. Maybe I'm just doing something wrong. On the other hand though... how many things can go wrong if all you need to do is supply the filename...?
_________________________________________________________________
Or do I need to download the whole MEGT128 library to have that working properly?
« Last Edit: October 28, 2016, 06:01:31 AM by N-drju »
"I don't know what 'pokygon' is but I like it."

Offline ajcgi

  • Member
  • *
  • Posts: 377
    • My little blogsite
Re: So I tried MOLA shader...
« Reply #1 on: October 28, 2016, 09:30:56 AM »
Can you post a screenshot of your node network please?
Make sure you're only picking the first of the img files.
It will take a long time to load them, sometimes minutes, especially across a network, but they should load in. In my experience there are occasions where Terragen quits immediately, or gets half way through loading and blanks the viewport, spinning the progress wheel as you say. Essentially the MOLA data is old and the node that reads it is also old. I am assured by Planetside staff that nothing will change there in the foreseeable future.

Offline N-drju

  • Member
  • *
  • Posts: 791
  • Changes, changes, changes...
Re: So I tried MOLA shader...
« Reply #2 on: October 28, 2016, 12:08:38 PM »
Hm... then it seems some patience will just do. Well... I can post a node network screenshot but there is nothing there! :D I'm loading this into a completely blank project so it's no use.

What do you exactly mean by saying that I should pick the first image file? ???
"I don't know what 'pokygon' is but I like it."

Offline ajcgi

  • Member
  • *
  • Posts: 377
    • My little blogsite
Re: So I tried MOLA shader...
« Reply #3 on: October 28, 2016, 05:31:03 PM »
The first file in the folder here is megc00n000hb.img
that's the one I usually load. Here is a typical Mars network and its settings.


Offline N-drju

  • Member
  • *
  • Posts: 791
  • Changes, changes, changes...
Re: So I tried MOLA shader...
« Reply #4 on: October 28, 2016, 06:44:52 PM »
So correct me if I'm wrong - I need to download the whole meg128 directory, use megc00n000hb and all the other files will load up all by themselves? Does it work like that? I will end up with Martian topography and colors?
"I don't know what 'pokygon' is but I like it."

Offline KyL

  • Member
  • *
  • Posts: 107
Re: So I tried MOLA shader...
« Reply #5 on: October 28, 2016, 07:18:12 PM »
Yes you need to download the *whole* folder. I suggest you use the 64 data set, the 128 is really huge....

You also have some pretty good data here: http://www.mars.asu.edu/data/
Also this guy did a nice job fixing those maps: http://planetpixelemporium.com/mars.html


Offline Oshyan

  • Planetside Staff
  • *
  • Posts: 11544
  • Holy snagging ducks!
Re: So I tried MOLA shader...
« Reply #6 on: October 29, 2016, 12:18:32 AM »
MOLA provides height but not color.

- Oshyan

Offline N-drju

  • Member
  • *
  • Posts: 791
  • Changes, changes, changes...
Re: So I tried MOLA shader...
« Reply #7 on: October 29, 2016, 08:00:58 AM »
That's okay, because I only need topography. However, from what ajcgi says I infer that MOLA shader is not one of your flagship creations? :P
"I don't know what 'pokygon' is but I like it."

Offline Oshyan

  • Planetside Staff
  • *
  • Posts: 11544
  • Holy snagging ducks!
Re: So I tried MOLA shader...
« Reply #8 on: October 30, 2016, 07:45:36 PM »
Yes, it is fair to say the MOLA shader is 'old'. As to whether it will be improved, I think in general we are looking to the general-purpose Geog Heightfield and Image Map shaders for any future georeferenced heightfield data import. Geog Heightfield already supports MOLA data, though few people seem to realize this. In fact the GIS format back-end we use for the Geog shader nodes is pretty flexible and supports many formats including moon data (LOLA), and most commonly available Earth DEM data, e.g. from the USGS.

Loading MOLA data with the Geog Heightfield nodes is not quite as "one-click" simple as the MOLA Shader, but it's a lot more flexible, powerful, and responsive in the end. To a single MOLA tile, you just add a Heightfield Load (DEM) from the Add Terrain button on the Terrain Layout, then navigate to where your MOLA data is and select the .lbl file (*not* the .img) for the tile you want to load.

If you want to load a complete set of given MOLA data, you just use the Heightfield (Load Multiple DEMs) option and scan the folder for the data you want to load (or manually add each .lbl file). It will take a while to individually load each tile but, unlike the older MOLA shader you'll get a clear progress dialog for each DEM that loads, and when it's all done you'll have individual control of every DEM that's loaded. Perhaps more importantly (for e.g. memory use), since georeferencing is supported, you can easily load a *subset* of the total data, using less resources, and still get the correct positioning, tile alignment, etc.

Having said all that, I only did some basic testing on the MOLA dat with the Geog Heightfield loader. It's possible there are some issues with it because it's mapping to  a Mars-size planet (which reminds me: make sure you change your planet size to Mars-equivalent for accurate results!). Let us know if you do see any problems with the above workflow.

- Oshyan
« Last Edit: October 30, 2016, 08:03:57 PM by Oshyan »

Offline N-drju

  • Member
  • *
  • Posts: 791
  • Changes, changes, changes...
Re: So I tried MOLA shader...
« Reply #9 on: November 02, 2016, 07:42:44 AM »
Hey,

For the moment, I moved on to something else, so I'll leave the MOLA shader alone for a while. However, I will let you know how the solutions offered worked for me once I am back at it. Your information should be well enough to crack it.
"I don't know what 'pokygon' is but I like it."