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View Full Version : Particles Receiving Shadows / Deforming HVs Issues - Lightwave 9.3



RPSchmidt
01-18-2013, 07:50 AM
Hello folks... relatively new Lightwave user, although because of my work, I have been saddled with a slightly out-of-date version (9.3).

I am building a volcano and working within several limitations (not the least of which includes: no liquid simulation plug-ins, i.e., RealFlow, no network administrative privileges to install any plug-ins or download and use scripts easily, etc).

Although those restrictions have been annoying, I have gotten reasonably close to my goal. However, I've run into a few snags that I am working through and wanted to ask for some assistance.

Particles Receiving Shadows Problem

1. I have a separate "smoke" particle emitter with Sprite HVs. The smoke looks great, and I have grouped it with a wind dynamic object. All of that works just fine... the issue I am having is that when the "volcano" erupts and the "lava" is blasted into the air, it is throwing shadows on the smoke which just looks... well, idiotic.

In the Render properties of the smoke emitter, I deselected "receive shadows" and "self-shadows". No change... the "smoke" still receives shadows from the "lava".

I also deselected those options on the wind dynamic, on the off chance that because they were grouped, that was having some kind of effect. Again, no change.

Deforming HVs

2. Although my surface "lava" Hypervoxels look very nice, with great shading and surfacing, I haven't been able to force them to deform away significantly from their spherical shape (except when they impact each other, etc). I have searched for answers that might help me with deformation of the HVs but haven't found anything that has resulted in a significant change.

I am currently re-calculating the dynamics in the scene to see if that makes any difference.

Any suggestions / assistance that you folks could provide would be excellent!

prometheus
01-18-2013, 08:14 AM
You better provide screenshot of the shadow issue...
As for deforming Hvīs ..since voxels are based on a pixel which is volumetric, it wil always be spherical (blobby) deformation is more like a cut in to
the spherical volumetric shape, and hypertexture takes care of that and the more you increase hypertexture strength the more it will cut in to it, also slightly same effect is to
use less density, a third way is to lower contrast in the hypertexture if it is available, like turbulence, in some cases you can go to negative values too.

then you have an option to scale down or up particle hv size depending on initial size and volume you have set up.
You also need to make sure they die out with particle age gradients in opacity, density or dissolve channel, even in thickness channel, you have to check what is best for your scene.
there is two techniques implemented in other software to avoid blobby stuff, but currently we do not have that in hypervoxels.

1. distance between particle gradients, that would dissolve hvīs particles where the amount of particles strays away.

2. we now have a blending mode for voxels in volume mode, but I havenīt seen anyone showcasing how those options would help in this case, this blending mode doesnīt work
as surface mode does, the surface mode has a proper tension blending between spherical shapes, ergo avoiding blobby look, there was a plugin called dynamite which had the same type
of blending mode with tension between voxels.

Heres some experiments with particle blasts..

Hypervoxels..
http://vimeo.com/45587582
http://vimeo.com/45100949
http://vimeo.com/27734204
http://vimeo.com/27400495

Dynamite...
http://vimeo.com/28587261

TurbulenceFD...
http://vimeo.com/35528035
http://vimeo.com/35832026

Thomas Leitner
01-19-2013, 09:05 AM
Deforming HVs

2. Although my surface "lava" Hypervoxels look very nice, with great shading and surfacing, I haven't been able to force them to deform away significantly from their spherical shape (except when they impact each other, etc). I have searched for answers that might help me with deformation of the HVs but haven't found anything that has resulted in a significant change.

Hi,
itīs really difficult to understand what you need without an images. Do you mean the shape from the Hyper Texture?
Another thing you can try is to shape the voxel on the basis of the surface normal of your volcano object.

prometheus
01-19-2013, 09:27 AM
Hi,
itīs really difficult to understand what you need without an images. Do you mean the shape from the Hyper Texture?
Another thing you can try is to shape the voxel on the basis of the surface normal of your volcano object.

have you used hv deform?, I have never been able to understand that thingy. or did you just use stretch gradients?

Michael

Thomas Leitner
01-19-2013, 09:42 AM
have you used hv deform?, I have never been able to understand that thingy.

Yes, HVDeform.
And yes itīs not very intuitive.
And I lost the manual. BTW if anybody has it, it would be nice to post it (I think itīs called waterpooldoc.pdf)!

ciao
Thomas

prometheus
01-19-2013, 09:54 AM
Yes, HVDeform.
And yes itīs not very intuitive.
And I lost the manual. BTW if anybody has it, it would be nice to post it (I think itīs called waterpooldoc.pdf)!

ciao
Thomas

I did a fast search, but nada, but I think I have packed somewhere, or maybe it might be on some of the lw 9 docs at our accounts?

the hv deformer additional plugin should be written in to hv surface settings I think, + better ui, and include the docs in latest lw documentation.
it helps a little obviously for better liquid stuff, a distance between particle gradient would further add realism, next step would be some physics solver with noise/turbulence etc..then were getting
somewhere:)

Ryste3d
01-19-2013, 10:51 AM
Don't know if this is what you are looking fore?

http://books.google.no/books?id=0dknRT34mhkC&pg=PA555&lpg=PA555&dq=lightwave+HVDeform&source=bl&ots=SvRPtvgZ2W&sig=zGmW9jvwpTbETlRYy6M4JvZZpNs&hl=no&sa=X&ei=K9n6UILjB8Km4AS--ID4BA&ved=0CEsQ6AEwAg#v=onepage&q=lightwave%20HVDeform&f=false

http://forums.newtek.com/showthread.php?53792-HVdeformer

http://www.youtube.com/watch?v=7cXMfB4SaeU

LW 11.1
HyperVoxels
Fixed Case 43862: HVDeform broken – appears to stretch rather than squash.

Thomas Leitner
01-19-2013, 11:54 AM
Don't know if this is what you are looking fore?

http://books.google.no/books?id=0dknRT34mhkC&pg=PA555&lpg=PA555&dq=lightwave+HVDeform&source=bl&ots=SvRPtvgZ2W&sig=zGmW9jvwpTbETlRYy6M4JvZZpNs&hl=no&sa=X&ei=K9n6UILjB8Km4AS--ID4BA&ved=0CEsQ6AEwAg#v=onepage&q=lightwave%20HVDeform&f=false

http://forums.newtek.com/showthread.php?53792-HVdeformer

http://www.youtube.com/watch?v=7cXMfB4SaeU

LW 11.1
HyperVoxels
Fixed Case 43862: HVDeform broken – appears to stretch rather than squash.

yes, thanks

ciao
Thomas

prometheus
01-19-2013, 12:02 PM
Thanks Ryste3d, have to check the pdf, based on the youtube vid..that wonīt get us very far:)
based on the thread,well people there describes their miscontent of the hv deform interface and docs in unison what I said about it too.

getting that hv deformer in the hv tab and easier to use, together with distance between particle gradients in all channels possible would do so much for the liquid look, I think more than what
was introduced newly with the new blending options.

Michael