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grc
07-25-2005, 10:20 AM
Hi,

I am trying to create an astroid and want to put a crater effect over the surface. So it looks like the craters are eating into the surface. I have tried a few procedural textures but they don't look right, has anyone any ideas on how to go about this?

Thanks

Gary

ACLOBO
07-25-2005, 12:05 PM
model it if you want it to look right. Procedurals acting as bump maps are only really good for things 6"inches deep or less. If you have real gouges and deep depressions, you need to model it.

-Adrian

WizCraker
07-25-2005, 12:08 PM
You can use displacement maps or you can model it.

So you want your Astroid to look something like this?

These are actual images of the Comet Temple 1 before impact.

http://www.nasa.gov/mission_pages/deepimpact/multimedia/PIA02127.html
http://www.nasa.gov/mission_pages/deepimpact/multimedia/070405-its-approach-x4.html
http://www.nasa.gov/mission_pages/deepimpact/multimedia/PIA02128.html

Or did you want to show the impact of the crater being created?

These are Actual Images of Temple 1 get hit by Deep Impact Probe.

http://www.nasa.gov/mission_pages/deepimpact/multimedia/PIA02131.html
http://www.nasa.gov/mission_pages/deepimpact/multimedia/pia02133.html
http://www.nasa.gov/mission_pages/deepimpact/multimedia/confirmation.html
http://www.nasa.gov/mission_pages/deepimpact/multimedia/pia02141.html

As you can see the impact to make the crater look alot different than when you see it on the big screen from hollywood. For one thing acorrding to the engineers at NASA since it is space the Debris moves in slow motion, therefore that is why the Deep Impact Ship was unable to capture a crater so long after the impact.

If you are looking for the craters like the first batch of files post impact of many months or years than displacement or modeling would be best bet.

If you use displacement you would paint the map. if you model there are many tools within Modeler that will allow you to do it. Magnet tool for instance.

grc
07-26-2005, 09:04 AM
Thanks for that, I wil try out the displacement map.

peteb
08-03-2005, 02:12 AM
I'd say the best way would be to to cut in the detail where you want it. I'd also use some photos of rocks as textures. You can get good results from procedules but a good rock texture without harsh light will work better in my opinion.

grc
08-03-2005, 03:00 AM
Thanks.

How would you cut that detail in and what tools would you suggest?
Also if you were going to combine rock textures how best to combine them?

I am rendering a still frame of about 4800X3400, which works out around 50mb, quite often when I use photo textures they appear quite blurred and fuzzy at that render size, I don't know if there is a way round this.

starbase1
08-03-2005, 06:16 AM
Hi,
I have tried this before and ended up admiting defeat. :mad:

The larger craters have to be done with geometry, but these things generally have craters down as small as the eye can see. :eek:

The bit I really ran aground on was getting the colours to react to the rims of the modelled craters, with an irregular shape it's pretty hard to do, to say the least... And when you start thinking of craters overlaying each other... :grumpy:

Maybe we could reform the old 'lets build a nebula' and 'lets build a planet' crew, to bash some ideas together?
:)

Have you got any attempts so far? I started with real asteroid geometry, and tried to add more detail...