I had a quick search of this forum and there have been a lot of questions about modelling a realistic earth model, and there are a lot of tutorials out there, yet still I have a question...
What I can't find is a way to tile or stack multiple textures on to a sphere to use as my earth textures. Specifically I want to use the 6 piece tile set from NASA (like this set of 6 21600 x 21600 res: http://visibleearth.nasa.gov/view.php?id=74142)*. I'm sure this texture set will be very slow to render, etc, but I'd like to get a really top-notch model of the Earth made and this is stage 1! If I get something as nice as I imagine I might be able to together I'll distribute freely (as all texture sets I intend to use are open source) at the end. The cost of some Earth models on TurboSquid is ridiculous and I'm sure it's possible to make something comparable.
I'm very new to Cinema 4D (and 3D in general), although quite experienced with After Effects, so I hope I'll pick it up reasonably quickly. Any help would be much appreciated, as would pointers to different resources for learning, etc.
*Ultimately, I'd like to be able to put individual satellite images of certain islands (like the UK) on top of that for even more detail where needed... But I shan't get carried away for now!
The way to go about it would be to assemble the eight individual tiles into a single gigantic texture (4 columns x 2 rows). Then it would automatically map to the default sphere primitive. NASA actually provides such an image, albeit at a lower resolution.
Would there be any difference in performance that way? Because it would mean having a texture that was 86,400 x 43,200 across... I really don't want to have to go smaller than there are freely available assets for, if at all possible! Thank you though, I think that is what I will try next!
I had the bright idea of splitting the sphere in to 8 and using the relavant tiles on each piece, but they don't line up. I don't think the square 21600x21600 textures map to the 8th of a sphere properly... Very frustrating!
it is easy to get the 8 textures to map on a sphere without having to join them all into one texture. Load a tile (A1) into a material, put it on the sphere, in the texture tag
-change Projection to Spherical
-turn off Tile
-set length U to 25%
-set Length V to 50%
All the textures will share the above settings, Offset U and Offset V will then position the tile
for A1 Offset U and Offset V = 0%
for A2 Offset U = 0% and Offset V = 50%
for B1 Offset U = 25% and Offset V = 0%
for B2 Offset U = 25% and Offset V = 50%
and so on for C and D...
Hi Brian, thank you! I'd actually just worked that out about 45 minutes ago but useful to have in writing online for anyone else. Cloud transparency and masking glows (on lights on the dark side of the earth) are my next challenges. Any further suggestions welcomed though!