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Cloud bumpmap simulation

Posted: 11.10.2005, 00:43
by LoneHiker
I'm new to Celestia, having only had it for less than a week. After finding out bumpmaps for clouds have not been implemented it occured to me that the effect could still be simulated, but only if a separate cloud layer is not critical to you. Here are a couple of screenshots showing the effect:

http://img.villagephotos.com/p/2005-10/ ... mpmap1.jpg
http://img.villagephotos.com/p/2005-10/ ... mpmap2.jpg
(These images may only be available for a limited time.)

The effect is much more apparent when the planet is in motion, and mostly as you approach the terminator (as is to be expected).

This technique involves 1) combining your cloud texture with your terrain texture in your paint program to create a new texture and 2) blending the cloud alpha mask with the terrain bumpmap so that the new bumpmap spans the combined heights of the two.

Since the cloud layer is now part of the terrain texture you'll want to turn off cloud rendering.

This makes a very nice "eye-candy" alternate surface if done properly but it's obviously not intended to replace high-resolution surface textures - although there is no reason why this can't be used for such, especially if psuedo cloud shadows are added. You just won't be able to go or see below the clouds. :P

Lone

P.S. Note the dust storm added off of the western Saharan coast and slash-and-burn smoke in central Africa and South America. :)

Posted: 11.10.2005, 02:51
by LoneHiker
Here's an animated GIF that shows the effect a little better:

http://img.villagephotos.com/p/2005-10/ ... umpmap.gif
(Again, image may only be available for a limited time.)

Here the bumpmap is being toggled on and off by pressing CRTL + V in Celestia. (Haze gets turned off too, unfortunately.)

Lone

Posted: 11.10.2005, 05:06
by Kolano
Very nice.

Any chance you can upload a pre-prepared texture to the Motherlode?

Posted: 11.10.2005, 20:59
by LoneHiker
Kolano wrote:Any chance you can upload a pre-prepared texture to the Motherlode?


Thanks for your interest. I don't think it's Motherlode-ready, since some of the land imagery is derived from Arc Science's copyrighted Face of the Earth (which I own but can't distribute).

But if you give me some time to substitute a Blue Marble map (hopefully one of the new Blue Marble Next Generation images due to be released October 12th) I might be able to e-mail you a copy of the files you'll need to try this out.

Just drop me an e-mail at my Hotmail.com address. My e-mail username is LONE_HIKER (you know how to complete the rest). I'll try to get the files to you as soon as I can. Probably next week at the earliest.

Lone

Posted: 11.10.2005, 22:01
by Don. Edwards
Are you sure those are ARC softs texturs. I have seen there textures and the coloring looks more in line with my work. Not saying it is, but again I have seen there works and the Earth in their textures is much more yellow. I hope I don't have somekind of problem starting here. Anyone else use ARC softs textures wnat ot do a comparison for me on the colors, A quick side by side comparison should be all it takes to answer my questions.

Thanks
Don.

Posted: 11.10.2005, 23:29
by LoneHiker
Don. Edwards wrote:Are you sure those are ARC softs texturs. I have seen there textures and the coloring looks more in line with my work. Not saying it is, but again I have seen there works and the Earth in their textures is much more yellow. I hope I don't have somekind of problem starting here. Anyone else use ARC softs textures wnat ot do a comparison for me on the colors, A quick side by side comparison should be all it takes to answer my questions.


Or you can just ask me. ;)

The surface map is a combination of Blue Marble, Face of the Earth and MODIS data. One flaw in the premise of your post is you assume I have done no editing. :P

The FotE data was used mostly as a luminance layer in some areas and a color layer in others - whichever had the most beneficial contribution. The base layer is an edited Blue Marble. In areas where I preferred the Blue Marble data the FotE data was removed or filtered.

The MODIS data was used to replace the Sahara desert, since I've found no textures that satisfactorily fix the problems the Blue Marble had in that area.

Most of the lessons I learned for making Earth textures are several years old. It didn't take a lot of work to make this particular texture because it's become rote for me.

I've seen your work recently, Don, after finding out about Celestia. My texture is not based on yours at all. :) In fact I just downloaded one of your maps from Motherlode and resampled it to 2k to fit over mine. I turned the layer on and off and the difference is significant in all areas.

Here is my texture:

http://img.villagephotos.com/p/2005-10/ ... MyWork.jpg
(This image may only be available for a limited time.)

I'm sorry for the watermark, but like I said there are copyright issues that I don't want to get involved with. I also had to compress the image heavily to fit within the byte size limit at VillagePhotos.

Please note the different color vegetation and oceans. Also note the different forest and ice/snow patterns in some areas and the total reworking of the Sahara.

Lone

Posted: 12.10.2005, 00:54
by Don. Edwards
Cool, you had me worried there for a minute. I can see the differences in your texture. Thanks for the info.

Don.

Posted: 13.10.2005, 00:33
by LoneHiker
Don. Edwards wrote:Cool, you had me worried there for a minute. I can see the differences in your texture. Thanks for the info.


No problem. ;)

I'll delete the file from VillagePhotos now. It's just eating my monthly bandwidth allotment.

Lone

Posted: 21.10.2005, 18:00
by Rocket Man
I think will be a nice thing to gas giant, like try it on Jupiter.

Those are really great pictures of the Earth. Makes them seem so real.











RM.

Posted: 03.11.2005, 13:11
by bh
Nice effect...I've been experimenting with bumpmapping clouds textures with some nice results...Jupiter for instance...