16k normal map of Ceres

General discussion about Celestia that doesn't fit into other forums.
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John Van Vliet
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16k normal map of Ceres

Post #1by John Van Vliet » 15.10.2016, 02:55

as the title states a work in progress for the DTM of Ceres

a 16k normal map and a gray texture -- so shading from the normal map only
Image Image

Image Image

Image Image

still working on the normal and the locations

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FarGetaNik M
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Post #2by FarGetaNik » 15.10.2016, 08:04

:eek: wow finally! All I could find was this: http://photojournal.jpl.nasa.gov/catalog/PIA20918 I was able to improve my bumpmap of Ceres, but wow, this looks great! Can't wait!

Hm seeing your post on Celestial Matters I must wonder why you simply use a highpass filter to remove the oblateness. I tried to extract the bulge from the texture with a horizontal blurr and it worked out fine, except with the low bit-depth in the preview you posted there are obvious arifacts. But this way I preserved large-scale topographic features.

I guess your approach is suitable if combining a normalmap with a 3D-model, but I don't like to limited possibilities Celestia gives me with that...

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John Van Vliet
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Post #3by John Van Vliet » 21.10.2016, 04:04

in my ssc for Ceres i use a oblate mesh

Code: Select all

 SemiAxes [ 487.3 487.3 454.7 ] # from dawn_ceres_v02.tpc
 

this likely will be updated

this makes my locations at the poles float above the Minor planet
Image

as you can see
Last edited by John Van Vliet on 21.10.2016, 21:05, edited 1 time in total.

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FarGetaNik M
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Post #4by FarGetaNik » 21.10.2016, 07:50

John Van Vliet wrote:this makes my locations a bit off at the poles
Image

as you can see

Celestia fails to reshape the planetographic grid when SemiAxes is used. It just "sqeezes" it in the new shape, but this distorts the angles of the grid. I've never checked if "oblateness" does the same, but it would be worth a try, since your Ceres parameters feature identical x and y axes.

Added after 18 minutes 52 seconds:
... I just checked it on the extreme example of Jupiter (it's odd seeing this planet as a sphere...) and it seems whether oblateness is on or off, the structures stay constant at the same latitude. So this should fix it :wink:


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