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prometheus
02-15-2013, 07:31 PM
Ivé been wanting to dig in to how Modo volumetric Item works etc...so I am discussing this on a thread over at luxology.

Now ...I saw this hand which looks sweet, and I can see how valuable modoīs new volumetrics can be for clouds, geometric shapes can be made volume item.

hereīs the hand image...
111600
also available as lux scenefile in the thread link below, and thereīs a short tute description if you would want to test modo out, very short demo limit period for it though unfortunatly.
http://forums.luxology.com/topic.aspx?f=32&t=67635

hereīs the thread I started to find out more about modos volumetrics.
http://forums.luxology.com/topic.aspx?f=4&t=73579&page=0

seems to render very fast if you look at Brad Peeblers volume item video, at least in preview, also it seems to blend much smoother, even though there isnīt any blending mode for particles.
Hereīs a quote from Andrew Helmer at the lux forums regarding modo not using rayleigh scattering...

"Actually, Rayleigh scattering is not very good for clouds, because Rayleigh scattering only applies for small particles, whereas water droplets (clouds) are fairly large particles. For clouds I think it's most common to use Henyey-Greenstein scattering (which is basically what modo uses), although I think Lorenz-Mie scattering can also be used."
shadow maps are also used.

Now... I hope improvements in hypervoxels follows this modo volumetric aproach, Im kind of a little fed up not getting what I want with them for clouds really...think Ivé been pushing them inside out to the most by now.

Michael

Celshader
02-15-2013, 08:02 PM
Now... I hope improvements in hypervoxels follows this modo volumetric aproach, Im kind of a little fed up not getting what I want with them for clouds really...think Ivé been pushing them inside out to the most by now.

Could Volumedic CE do this?

prometheus
02-15-2013, 09:00 PM
Could Volumedic CE do this?

I think you can make mesh a volumetric object with that, though I havenīt seen any good example of it, elmar posted some samples of clouds..but that was a little different, and I didnīt like the
volumetrics from that actually.
We really need this inside of hypervoxel rewritten or improved somehow, otherwise it fails to compete with pyrocluster, modo volumetrics, vue metaspheres, and the king of them..houdini.

you can see how fast modo renders the volume item, also..take a look at how the volume blends..seems much smoother than hypervoxels, I do not know why and how that is, maybe because of the different lighting model...
https://www.youtube.com/watch?v=aEghi7jkvbQ

hereīs the cloud fly through, a little better work on the air/sky here..I think it is to dark and too little scattering, then reduce the amount of texture cut throuhg, and remove the lower cllipping on the whole cloud, then it would look really great...
https://www.youtube.com/watch?v=-MXug_ZGUMY

the issue with hypervoxels hypertextures..even using only one null item, it is that hypertexture is cutting and also texturing density almost equally over the whole volume..but for real clouds and smoother ones, you would mostly like smoother overall look and texture more affecting the rim edges, that depends sometimes on lighting angles though.

you can improve it by using local density on dissolve channels of texture value..but there is no way to adjust the hypertexture to be smooth like that.
Vue clouds does a quite good job with it, but that isnīt perfect either.

sample image link..gardner clouds just a fast setup and compare, right image smoothed out with photoshop perhaps too much, but something in between is what looks best I think.
111602


1.the first thing would be to get volume item to hypervoxels, I ranted about that ages ago refering to houdini and implicit surfaces to convert geometry to volumes, and now modo got something like it.
2. next ..get shadow maps in there.
3. fix volume blending mode when using particle or nulls together, a proper tension blending ala metablob is needed
4. do check in to a better illumination models for clouds, suggestion would be to keep rayleigh as an option.

Do that And we are on the fly to great clouds:)

Michael

rcallicotte
02-16-2013, 09:13 AM
Good thread and interesting subject. Some of these look almost good or better than the Terragen 2 clouds.

prometheus
02-16-2013, 09:41 AM
Good thread and interesting subject. Some of these look almost good or better than the Terragen 2 clouds.


which images? clips? looks as good as terragen?

Michael

stevecullum
02-17-2013, 04:14 PM
geometric shapes can be made volume item.

You can sort of do goemetric shapes in LW - not exactly like the modo version and my shading sucks compared to those gardner clouds samples!

More effort needed....

prometheus
02-17-2013, 08:26 PM
You can sort of do goemetric shapes in LW - not exactly like the modo version and my shading sucks compared to those gardner clouds samples!

More effort needed....

Well...sort of, not volumetric objects truly, only point vertices and point clusters, and the local density gives the typical shading around each point in space and next to each other they are giving a sharp round cut.
Thatīs why we should rant to have true geometry volumetrics avoiding such issues.

on that hand sample...how did you make the hand shape? just curious if you added it to vertices, or if you used the fill solid tool? the fill solid tool letīs you fill geometry with points, but at the end of the day, most
of us will have it the same look as you with blobby hvīs.

Try and use beer illumination, I think that would ease up on the scattering and make the shading a little better.

By the way, if you use sprites instead, you would get a much better volume blending, and make sure points are sort of quantized, that is sort of fixed distance between every point, the
human eye sees difference much clearer than fixed patterns, ergo your eyes are fooled that way.
you could set up a null and luminosity gradients based on that to give appareance of volume on the sprites.
I think you might be able to bake luminosity too somehow and apply as vertex map ..or something?

I recall trying houdini and just create a shape, make it volumetric..voila instant volume shape from which you could add fractal noise, I believe it has good ways to control edge rim of the volume to have more
noise and less withing the volume.
No wonder Houdini has been one of the top tools for superman fly through clouds, or time machine or airline commercials.

I saw a tutorial once for old Houdini using image3d rendering to disc and metaballs on to L-systems, and the level of control for density and turbulence to create
a mushroom cloud was sweet, though I believe it is more common now to use true full volumetrics nowadays in houdini instead of image3d.

If modo has just as sweet sky like dponīts sunsky, then modo will be showcasing very very nice clouds soon.
Would like to get my hands on modo demo...but Ive been reluctant due to itīs frankly lousy demo period and limit of 15 days.

Michael

Elmar Moelzer
03-18-2013, 08:05 PM
Yes, you can do this with a feature in VoluMedic. Apply the Complex Object Custom Object plugin to a polygon object and make the object 100% transparent.
Then you can just use the complex object as usual.

prometheus
03-18-2013, 08:13 PM
Yes, you can do this with a feature in VoluMedic. Apply the Complex Object Custom Object plugin to a polygon object and make the object 100% transparent.
Then you can just use the complex object as usual.

And that is featured in the CE version and demo version too?

curious though about illumination model within volumedic, also how it would be possible to add noise/fractal within that geometry volume shape, preferably controlable to have
more noise at the geometry boundary edges or vice versa, to get good cloud results I can imagine a need to control volume thickness in the same manner too.

As for hypervoxels we do have a thickness control texture channel, but that hasnīt been working ever as I recall, at least there isnīt any decent gradient controller for that.

Migth test volumedic again, had some issues with it after installing with menus, and lack of datasets brought lack of interest in it, But please inform about the mentioned above regarding if
it is featured in those versions?

I noticed a new houdini release with special cloudFX tools based on open vdb & sculpting tools.
http://www.sidefx.com/index.php?option=com_content&task=view&id=2445&Itemid=66

if volumedic can display equally nice scattering of light and shades as hypervoxels, it would be very interesting, nothing wrong with
dpont sunsky and sunlight with hypervoxels..see images.

Michael

bobakabob
03-19-2013, 01:48 AM
Agree with Michael, it would be good to see Hypervoxels updated in Lightwave.

Elmar, any chance of seeing some Volumedic clouds or particle effects?

Netvudu
03-19-2013, 06:39 AM
We really need this inside of hypervoxel rewritten or improved somehow, otherwise it fails to compete with pyrocluster, modo volumetrics, vue metaspheres, and the king of them..houdini.



I know Iīm not helping,but seriously, volumetric clouds in the new CloudFX in Houdini 12.5 is so easy is not even fun. Weīve been loosing heaps of time...

geo_n
03-19-2013, 07:35 AM
Modo particle sculpting looks pretty easy to use. Possibility of sculpting clouds with familiar modelling tools.
Extremely tempted to get a copy of modo since the learning curve is much easier than other appz.

http://www.youtube.com/watch?feature=player_embedded&v=kU2OeNQcwSM

prometheus
03-19-2013, 09:57 AM
I know Iīm not helping,but seriously, volumetric clouds in the new CloudFX in Houdini 12.5 is so easy is not even fun. Weīve been loosing heaps of time...

yes I noticed the release of it and undstood that they had some serious help collaboration from ILM with this, suspect nothing beats that, however..I havenīt seen any clip of it in action, just a few images, but to see it in action would be nice, got to keep my eyes on the sidefx forums, and later download the apprentice version again, it stopped working a few versions ago.


Modo particle sculpting looks pretty easy to use. Possibility of sculpting clouds with familiar modelling tools.
Extremely tempted to get a copy of modo since the learning curve is much easier than other appz.


Yes...two features here that made me more and more interested of it, the volume Item from geometric shapes which the thread is about, and now these new particle implementations
that seems to surpass Lightwave particles.
Again as mentioned before, here we can see the importance of getting modeling core tools in layout or the scene directly to paint weights or texture density or sculpt particle clusters directly in the scene.

A volume Item method for sculpted geometry like modo or Houdiniīs ISO offset volumetric tools/cloudFX is what needs to get in to Lightwave very soon.
Along with a proper blend tension mode between two volumetric items, we supposly got volumetric blend mode in latest hypervoxels, but that seems like a joke really, havenīt seen anything useful with it, should be closer to the ol dynamite voxel blending mode to be correct, this will help cloud point clusters look better even though the best overall cloudscapes would probably derive from geometry shapes, and also textured based infinite cloud layers like ogo taiki had.

Michael

Matelot13
03-20-2013, 08:24 AM
You can use this in LightWave, wish we had it in modo. Maybe with 701...

Turbulence FD (http://www.jawset.com/)

prometheus
03-20-2013, 02:25 PM
You can use this in LightWave, wish we had it in modo. Maybe with 701...

Turbulence FD (http://www.jawset.com/)

yepp..kind of works too, not ideal though, have to check illumination model etc..and you need to specificly save out dedicated cache folder and sim the first frames for every change that is done.

But shapewise it is very nice...but to compete we need a non simulating geometry volume based tool inside of native lightwave,(modo and houdini has it)
It is also more cumbersome to set up with fluids and huge scale sims is a clogger.

Ivé experimented with that before, right now I have installing issues with turbulence and will get back to that later..you can pick up a sample scene of a simple geometry shape and fluid from e here in this thread...
http://forums.newtek.com/showthread.php?129022-Free-scene-setup-TubulenceFD-fluid-cloud-model-test-from-geometry!&p=1265151#post1265151

fluid simulation on poly plane with textured surface density, noise added with subgrid detail in different stages...
http://forums.newtek.com/showthread.php?126567-Volumetric-cloud-techniques-Hypervoxels-TurbulenceFD-Volumedic-Ogo-Taiki-Ozone&p=1238478#post1238478




some old fluid cloud test...
simulation progress..and vpr check.
http://vimeo.com/38310716

Evolution test...
http://vimeo.com/53969414

Elmar Moelzer
03-20-2013, 08:24 PM
Admittedly, we did not focus on clouds, fire and simillar effects with the first version of VoluMedic CE. We dont want to step on the toes of other LW plugin developers.
VoluMedic does allow to use a polygon object as a container for a volume. VoluMedic does not really offer a choice of shading models, but rather a way to light each sample of the volume to create the desired look. That can be used for clouds as well as solid objects. The first version of VoluMedic CE is most suitable for solid volumetric objects (and that is not a contradiction).
We will see about future iterations.

prometheus
03-24-2013, 11:03 AM
I posted this on another thread, what about openVDB?..something to include inside of native Lightwave perhaps or could it be helpful inside of volumedic?
Itīs open source and available as download with all that comes with it.
Itīs developed by dreamworks to handle sparse volumetric data and simulation efficient, and with collaboration with sidFX and implemented fully in Houdini, along with further developed
cloudFX tools.

http://www.openvdb.org/

Michael

Elmar Moelzer
03-24-2013, 06:59 PM
Yeah, I would love to go that way eventually. Part of the idea behind VoluMedic CE is that you can build completely volumetric objects. Right now this works best with solids though.