Some of the things that I think I've never uploaded, in no specific order

Started by Chinaski, April 22, 2012, 09:20:19 pm

Previous topic - Next topic


Thank you. :)

And because I don't want to up this topic without posting something... Here is the (huge) texture I'm working on...

Now I need to add more details on closeup views. ;D

This is just a test scene with files coming from HiRISE (here is a discution about it) and it's a nightmare to work with on my old computer. After this tests, I hope I could make a scene, with the same technic, and about the Curiosity rover. Maybe maybe maybe... If I'm lucky, and I find the time to do it.
You don't understand me ? That's normal, I don't speak english.


Some nice detail in there. I really hope you are not still using the Technology Preview v1.9 like it says in your images!

Just because milk is white doesn't mean that clouds are made of milk.


Ahhh, Mars data! Excellent, I was hoping to see some of this stuff used in TG. What is your workflow to get the data into TG?

- Oshyan


This is interesting too.

When you have the time, and if you have the desire. Would you mind doing a break down of this process/steps.
There does not seem to be a lot of this yet, perhaps its an advanced topic? The discussion link you gave feels like it is not for HiRISE beginners, and certainly not for people who haven't even started yet;)

It has been eaten.


@Matt -> Yes I am. I know it's a shame, definitely need to upgrade my TG2 version. Build 2.3 free is downloaded, I'll try to install it this week end. :)

@Oshyan & TheBadger -> If you remember that (four years ago), you know I'm a big fan of Mars exploration programs... So when I saw Jo explanations about HiRISE, belive me, I was very excited!

So I try to understand and execute the technic... And it was an epic fail! Reasons are: My english isn't good enough to understand IsisSupport technical topics. I had difficulty to run Gdal. And my GeoTiff converted files couldn't be imported in TG2 (I've no clue what was wrong). A totale failure. :D

So I was bored, and I decided to cheat. Here is my (wrong) methode (hard to explain, but nothing complicated):

First download the dtm you want... You'll need the black and white altimetry (IMG) and the surface map (JP2) (preview them in "PDS Extras").

Now you need to work and convert this very big files, that's the tricky part... After many unsuccessful attempts I found fwtools (it use the Gdal library). You can use it to view and convert the IMG or jp2 files via an interface. Theorically you can also crop, rotate or do whatever you want. I was unable to rotate, crop, or export a valid GeoTiff file. So I used fwtools to reduce and convert IMG (altimetry) and JP2 (texture) files in standard image file format. :/

Rotate, crop, and alignment, was done in photoshop. Finally you have two black and white files. Nothing else to do with the altimetry file (you can play with levels if you want)...

For the surface map you need to do a fake color map. For that I used (several times) the color gradient convert photoshop function, with altimetry as mask. The thing is... color image, this big, with multiple layers, are way too heavy for my computer... So I'm working on a small scale image, building a script, and when I am satisfied, I apply the script to the big images (my surface image was subdivided in four parts).

Your computer will compute for a very long time... Meanwhile you can do something else (play Ping-pong or read a book).

When it's done: You have a black & white altimetry, and a fake color map (in several part). You can open TG2. \o/

Terrain work ("->" is a link between 2 shaders):  One image map shader (your altimetry image, plan Y projection, position center, good homothetic size) -> a displacement shader (you can calculate the displacement value from "Extras Read me" on DTM page) -> an heightfield generate (same size, no fractal variation) -> an heightfield smooth (to smooth the stairs, value 3.5 for my scene) -> The heightfield shader (center). Topography, it's done.

Surface work (with a 4 part texture): Image map shader 1 (your first fake color image, plan Y projection, position -width/4 0 height/4, size width/2 height/2) -> Image map shader 2 (your fake color image number 2, plan Y projection, position width/4 0 height/4, size width/2 height/2) - >Image map shader 3 (your fake color image number 3, plan Y projection, position -width/4 0 -height/4, size width/2 height/2) -> Image map shader 4 (your fake color image number 4, plan Y projection, position width/4 0 -height/4, size width/2 height/2)...

Add some micro displacements, fake stones, and render the scene. VoilĂ  !

Let's be clear, it's not "the" good method. It's ugly, it's messy, it's wrong (we lose the altimetry data), but it's working. Now, if somebody know how to do that properly (with free softwares), please, please, please, explain to me (step by step). ;)
You don't understand me ? That's normal, I don't speak english.


Thanks for the details. It's a shame you're so limited by your computer at the moment. I can't imagine what you'd be able to do with a more capable system, given what you've created so far!

- Oshyan


Thanks for the explanation 8) Hope someone can answer your question here too!
It has been eaten.


Lots of great stuff here.

Quote from: Dune on April 23, 2012, 04:52:28 am
... And of course the problem with image tiles is that they are repetitive.

This article was written for web design but the principle applies to any image tiling