MOLA Map shader

[trailgirl]

Hi everybody, I've been trying to figure out the Mola map shader so I can do some Martian terrains. I found this page:

http://pds-geosciences.wustl.edu/missions/mgs/megdr.html Mars Global Surveyor: MOLA MEGDRs

Is that the right place to get MOLA data for Terragen?

I downloaded these files: megt90n000eb.img and megt90n000eb.lbl In TG2 I selected MOLA Map Shader from Add Terrain and got a bunch of error messages about files not found, I clicked OK on each error. Then I tried to add megt90n000cb.img with "Image filename" but it says it's unable to open megt90n000cb.imgmegt90n180gb.img Does this mean I need more img files? Any suggestions appreciated!

[rcallicotte]

I never got this to work correctly.  Not sure why.

[DeathTwister]

Yes, I was wondering about the Mola shader as well, and how do we use it? It would be sweet if we had a good tutorial to go to about now for it??? /hint /hint if there is one anyway.  That would be sweet.  Maybe contact MeltingIce and ask him?  hes good at that stuff /winks......
DT

[Matt]

Hi Trailgirl,

There are 4 different sets of data that you can use. If you click on the "Data set" dropdown in the MOLA shader you can see the format of the filenames that are needed. The files you downloaded have "eb" in the filename, which means they are from the "4 pixels per degree" dataset. [EDIT: the 4 pixel/degree set is not supported by the MOLA shader]

On the website you linked to you can also download the data for 16, 32, 64 and 128 pixels per degree. However, the 64 dataset is split into 4 tiles (4 .img and 4 .lbl files, 8 files in total), and the 128 dataset is split into 16 tiles (16 .img and 16 .lbl, 32 files in total). For the best reliability in TG2 you should stick to the 16 or 32 datasets, as these only use a single tile. The default setting for the MOLA shader is 64, but it's probably best to get to grips with the lower sets first.

Matt

[Matt]

Correction to the above: the MOLA shader does not support the 4 pixel/degree dataset. The first option in the dropdown corresponds to the 16 pixel/degree, or "megt90n000eb.img/lbl" files.

[trailgirl]

Thank you! This is fantastic! When the terrain first loads it looks really strange with a tall spike and radiating grooves but I zoomed out and moved around the planet (Planet 01) and then found some interesting craters and canyons. I can't tell if the terrain covers the whole Terragen planet or not, and I'm not cmpletely oriented as far as finding specific craters and mountains but it's a great start. I've been playing around with surface layers at various altitudes with different colors, it really brings out the terrain, especially when zoomed out to see the whole planet.

[4Runner]

I am not sure i figure out, which exactly files i can use, cause i used 64 and if i input mola
Topography      
megt00n000gb.img,
megt00n00gb.lbl    
megt00n180gb.img,
megt00n180gb.lbl

but it doesnt work, you can do it in different way with 3DEM but i dont like it

(if you can write exactly the names of files i will thank you)

[4Runner]

how you can stick them together?

[Oshyan]

The .img files are what you want to load. As Matt said above, it's more reliable to use the 16 or 32 data sets. But I believe you should be able to load the 64, though I'm not sure if it will stitch the tiles or not. But if you're getting no result whatsoever I think you must not be doing something quite right. To be sure that nothing is wrong in TG2, I would try using the recommended data sets and, if you have success with those, try replacing them with the 64.

- Oshyan

[4Runner]

i understand it i need .img files, labels are only carry specific information

but say me what i do it wrong,
1. i make a new scene
2. click on terrein ->Add terrain -> Displacement shader -> Mola map shader
3. from menu i choose 32, and open megt90n000fb.img
but nothing happened, whole planet it still empty,
i grow up Height multiplier and its lift up some parts of terrain, but we cant talk about the cannons.

64,128 can have more details but how i cen give them to scene? make four MOLA shaders, it will mapping right? Idont know if TG2 is using degrees when mapping or how he is mapping it.

[trailgirl]

4Runner, you may need to zoom out to see the whole planet and move around to find some features. I have my camera set on :
xyz: -6.39024e+06, -2.63101e+06, 2.11498e+06 for a view of a lovely canyon.

[4Runner]

ok i have last question, how i can map the 128 or 64, its 4 and more .img files, show me the way how correctly map it pls

thank you all for help

[Matt]

You only need one MOLA Map shader in your scene. It reads multiple files from a folder and maps the whole planet.

I think 128 is unreliable (or very inefficient), but 64 should work. Simply choose one of the .img files in your 64 folder and the shader should automatically: A) remove the filename from the path so that it just points to the folder, and B) change the data set option. It will do that automatically. All you need to do is choose one of the .img files. You need to have downloaded all the files for the 64 data set and put them in the same folder.

Matt

[Matt]

If you only want to use a single tile from the data set, you can just load the .img file using a Heightfield Load just like any other terrain or image file. The MOLA Map Shader is designed to map the whole planet using all the files in the data set (resolution) of your choice.

Matt

[4Runner]

thank you very much