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View Full Version : Baking HV Volume oddness



jds580s
06-07-2004, 03:40 PM
I'm working on a short Hypervoxel cloud animation, and it's the first time I've had a chance to use the Baking options for volume HV's.

I am happy with the look of the Volume HV's rendered as a volume, and also with them rendered as a baked object, but when I scale the object up or down things get strange.

The smaller the object is (object is just a bunch of sprayed points from modeler) the darker everything gets to the point that it's totally black, and the larger it gets the HVs become more white.

The OpenGL view of the HV's looks good at all sizes. There are no sized based gradients or anything like that, in fact the HV settings are very simple.

If anyone has any advice it would be most welcome.

Thanks!

Justin

Phil
06-07-2004, 08:48 PM
I am happy with the look of the Volume HV's rendered as a volume, and also with them rendered as a baked object, but when I scale the object up or down things get strange.


It doesn't help you, I know, but I've tended to find that baked HVs look absolutely nothing like the original setup so I would love to know how you got yours to look good post-bake.

In general, I've resorted to using sprites and/or composited sequences to offset heavy render times, assuming that's what you are looking for. *shrug*

jds580s
06-07-2004, 09:48 PM
:) Thanks Phil, it's nice to know I'm not alone.

I was going for that news station 3d weather clouds graphic look that some of the higher-end stations are doing in my area. It's a volumetric little puff of clouds.

I used HV's and was -ok- with the results. When I baked them it removed a lot of the details and smoothed things out... I was actually happier with that than the 30second HV's I originally created. :)

Unless this oddness is some kind of feature that I can't figure out, it looks like a bug to me.

Another thing I didn't mention in the first post, the smaller I scale them the faster it renders the larger I scale them the slower it renders (taking the same about of space in the camera, it's parented to the cloud see pic.)

Phil
06-09-2004, 08:36 PM
Originally posted by jds580s

I used HV's and was -ok- with the results. When I baked them it removed a lot of the details and smoothed things out... I was actually happier with that than the 30second HV's I originally created. :)


From my brief investigation (I gave up and just added this to the LW bug list in my head and reported it to no avail), baking seems to drop the intensity way down. By the time I had added HV-specific fill lights or cranked the luminosity up by several thousand percent to restore the look, I had no saving on render time. Sprites, on the other hand, work well in combination with standard volume HVs. Combining the two helps to get a reasonable compromise.



Unless this oddness is some kind of feature that I can't figure out, it looks like a bug to me.


From the description in the 7.0 manual, it seems like a bug to me. Baking in general seems, umm, half-baked to me across the board. I asked questions about it for 8.0, but never got a response (baking lighting, etc. doesn't generate intelligent image sequences in response to lighting changes on the lights being baked, etc.).



Another thing I didn't mention in the first post, the smaller I scale them the faster it renders the larger I scale them the slower it renders (taking the same about of space in the camera, it's parented to the cloud see pic.)

That might make sense because you are increasing the actual volume being rendered, irrespective of the camera view. The renderer has a large world volume to deal with - your lighting changes kind of show this. It's not a totally isolated volume in the world - it's still interacting with light sources. I'm only speculating because it never gives me the effect I am after, so sprites+volumes+fake geometry are my volumetric toolkit of choice.