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lynbo

Erosion Effects

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Can you tell me how rendertimes (6 min per frame 512x384, th scene in movie) compare to other volumetric things, as in very fast / fast / normal / slow ?

I'll make some more...

The large render of this mountain:

http://dmytry.pandromeda.com/mojoworld/sno...ns_5c4_jq95.jpg

(what's i personally love about fractal erosion is that i can make large renders with a lot of details)

To avoid confusion, it's MojoWorld 3.1.1pro plus Volumetrics plugin plus results of my fractal erosion research (nobody ever did such erosion before :) ). The MojoWorld provides procedural modelling(including procedural modelling of clouds), my Volumetrics provides rendering, and my experimental implementation of erosion fractal erodes the landscape. MojoWorld itself is not very good at rendering, but for it's small price, is surprisingly good at procedural modelling of such things.

I might make port for Houdini if there will be professional demand for commercial version (that will be rather pricely) & if it can be competetive, as i know there exist good volumetrics renderers already...

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wow...

http://dmytry.pandromeda.com/mojoworld/sno...ns_5c4_jq95.jpg

last year flying to LA for SIG I saw actual real life mountains that looked just like this... :)

as for porting your Volumetrics plugin to Houdini - I can say that I'm sure it would be very competetive with existing things in Houdini (non-proprietary...)

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should the codebox be converting the code into smiley's?  I don't think that's right...

24397[/snapback]

lol

thats really funny

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comming in kind of late here...

Clouds are tricky because of the shape and details they have, and especially because of how light acts in them. Certain cases are much more forgiving than others, but on Stealth we had to come up with some interesting techniques to give us some of the stranger behavior that light has in clouds. The edges in particular can be either light or dark, depending on the viewing angle, and don't always behave the way you'd expect.

Also, building clouds low res and then scaling them up at rendertime only works to a certain extent. We always assume clouds are these fluffy soft things, but they really have an incredible amount of detail in them and we were constantly asked to add more detail to clouds in Stealth. We did have a feature to add noise at rendertime to baked out clouds, but you have to be careful about how you add noise, because simply adding noise can make things look crunchy and not realistic.

As far as rendertimes, I don't remember exactly. The baking of the clouds to a library could be quite expencive at times, taking many many hours and lots of ram. Once clouds were on disk they could be rendered quite fast... anywhere between 10 minutes and an hour for a 2k frame depending on complexity. The one thing that did take a long time was computing shadow maps, but since the clouds didn't move, we could do that once for a shot and be done with it.

Cheers,

Jens

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comming in kind of late here...

Clouds are tricky because of the shape and details they have, and especially because of how light acts in them.  Certain cases are much more forgiving than others, but on Stealth we had to come up with some interesting techniques to give us some of the stranger behavior that light has in clouds.  The edges in particular can be either light or dark, depending on the viewing angle, and don't always behave the way you'd expect. 

Also, building clouds low res and then scaling them up at rendertime only works to a certain extent.  We always assume clouds are these fluffy soft things, but they really have an incredible amount of detail in them and we were constantly asked to add more detail to clouds in Stealth.  We did have a feature to add noise at rendertime to baked out clouds, but you have to be careful about how you add noise, because simply adding noise can make things look crunchy and not realistic.

As far as rendertimes, I don't remember exactly.  The baking of the clouds to a library could be quite expencive at times, taking many many hours and lots of ram.  Once clouds were on disk they could be rendered quite fast... anywhere between 10 minutes and an hour for a 2k frame depending on complexity.  The one thing that did take a long time was computing shadow maps, but since the clouds didn't move, we could do that once for a shot and be done with it. 

Cheers,

Jens

24941[/snapback]

Thanks for reply!

Yes, sounds sort of like how my one works... with exception that i don't have saving of illumination data to disk, i.e. it is computed in memory but isn't saved. Maybe will do that for some flight scenes, though i was always more interested in morphing clouds and changing beams of light going through morphing hole in clouds etc.

By rendering at lower resolution i meant the chase scenes where camera turns quickly and there's a lot of motion blur everywhere so details aren't visible. Indeed sometimes clouds has lot of details, esp. close to horizon. I even render my best images with supersampling...

Borders of clouds is indeed hard to do realistically. Anisotropic scattering and everything... i spent quite a lot of time looking at real sky, and at real photos...

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