Ordnance: Hypervoxels 2.0 and Lightwave 5.6
thing that is impractical or even dangerous to deal with on
most shoots is firearms. They require expensive insurance, handlers,
and even then can still be very dangerous (Witness what happened
to Brandon Lee on the set of The Crow). With modern digital
effects processes and replica firearms like Airsoft guns, it
is possible to use firearms on a shoot without any of the inherent
dangers usually associated with them.
even more difficult to shot with and around is any type of heavy
ordnance, for instance a rocket launcher. In this tutorial I
will get you well on your way to producing a good rocket launcher
effect using NewTek's Lightwave 3D version 5.6 and Hypervoxels
2.0. Hypervoxels is currently available as a separately purchasable
plugin for Lightwave, but its features are being incorporated
into NewTek's next release of Lightwave, Lightwave . Hypervoxels,
in its current incarnation, uses particles to locate the center
of each mass within the volume. You then set the size of said
masses and Hypervoxels make a volumetric object on rendering
that represents the mathematical volume created by these two
pieces of data. The term 'voxel'
is a relatively new computer graphics term, meaning 'volumetric
found a Trendmasters toy at a local toy store that pretty accurately
duplicates the size, appearance and operation of the U.S. Army's
M72A2 Light Antitank Weapon and filmed a friend 'firing' it.
I then digitized the footage into my PVR and trimmed it down
to the essential cut using the PVR Player software provided
with the PVR. DPS products (the Perception or PVR, Hollywood,
PVR-RT and the new Reality) are excellent for use with Lightwave
because it presents each video clip as a directory filled with
an image sequence for that particular clip. Lightwave at present
cannot natively load .AVI or .MOV files (but there is a plugin
enabling it to read AVIs) so with most other NLE cards, you
have to process the video files into an image sequence and load
the resultant image sequence into Lightwave (thus taking up
hard drive space with large numbers of uncompressed video frames
duplicating the contents of your video clip).
thing I had to do was create a 'dummy' version of the prop LAW.
This was made to match the extended length, tube diameter and
thickness of the prop.
loaded my trimmed image sequence as a backdrop in Lightwave,
set Lightwave for Wireframe preview, and generated a full-length
version of the preview. I then saved the preview to disk, reloaded
it and set my background image to be the preview. I did this
to increase my preview speed, because instead of having to load
each background frame from the Perception, it simply shows the
to build a background (to project the video onto as a texture)
and a matte object (just a flat polygon to project the holdout
matte onto) and then I tracked in a holdout matte in Effect*
my earlier tutorial) and generated an alpha channel for
the matte object, which I applied as a clip map.
to see the scene setup
I then moved
the pivot point of the dummy LAW object from the center of the
object to the rear and down so the ivot point was placed approximately
where the tube rested on the talent's shoulder. As I match-moved
the tube to the motion of the tube to that of the prop, moving
the pivot point ensured the best duplication of its motion.
to see an AVI of the match move
roughly did the matchmove (the above preview was made of the
rough matchmove) and then went back and refined it, mostly
by adjusting the tension, continuity and bias of the individual
keyframes in the LW motion graph.
I then modeled
the LAW rocket itself (excuse any inaccuraces, I couldn't remember
hot many fins it had) and made a fin object with its pivot point
through the hole where the shaft on the rocket would fit. I
loaded the rocket and fin objects into the scene and positioned
the fins on the pivot pins on the rocket. I selected the dummy
LAW object within the scene and used the motion graph to save
its motion, then reloaded the motion onto the rocket and offset
the rocket's motion back by the same amount I shifted the pivot
point of the tube, thus ensuring the rocket moved properly within
the tube during the matchmove. I deleted all keyframes for the
rocket object after the keyframe where i wanted the 'launch'
to start, and then saved this motion (again) and added a light
to the scene and loaded the motion onto the light. By doing
this, I could select the light and use Light View in Layout,
then boresight (look down the tube of the missile launcher)
the motion of the rocket after launch to make sure it was flying
up the scene in PS2. click for a larger image.
Particle Storm 2 (the full version of the particle system plugin
from Dynamic Realities)
and started setting up the particle effects. I initally created
two particle groups, one for the fire of the rocket exhaust
and a second for the smoke trail left by the fire. The fire
was set to emit from a section of the inner rocket nozzle I
saved seperately for just such a purpose, and after saving the
initial object for the fire particles, I set the smoke to be
spawned by the fire based on the age of the fire particles,
so just before the fire particles started to die they spawned
the smoke. I used the following collsion objects: a copy of
the body for the LAW and parented it to the copy of the LAW
tube in the scene, and a copy of the rocket parented to its
equvalent in the scene. Then I parented the emitter for the
fire to the rocket with a small offset (-1cm on the Z axis)
and recorded the PSM files.
the particle objects into the Lightwave scene and applied their
appropriate displacement files, and then applied the Hypervoxel
Particles displacement plugin to them. This plugin allows for
the Particle Storm plugin to supply various data about the particles
to Hypervoxels, including color, age, alpha channel (or dissolve
from particle storm), and size. Both were set to supply position
and alpha data to Hypervoxels, and the fire object was also
set to supply Age data.
up the fire in HV2
click for a larger image
color gradient for fire effect
the fire and smoke objects in Hypervoxels and started by applying
the preset flames effect. Though alot of people frown
on using the presets, with Hypervoxels I find them to be a very
good starting point. From there I proceeded to tweak the fire
settings, first changing the luminosity settings a bit, then
by creating a custom color gradient for the fire based on particle
age, starting from a rich bright yellow and gradually turning
to a deep red. I also in the process found that applying a sine
hypertexture inscresed the apparent detail of the fire, and
changing the frequency filter setting from 'loClip' to 'Sine'
got more of the appearance I wanted.
click for a larger image
smoke, I started with the 'Soft Cloud' preset and tweaked from
there.i found their soft cloudd settings to have too much of
a tendency to produce puffballs... that is, parts of the 'cloud'
were bulging off in distinct spheres betraying the nature of
hypervoxels... essentially procedurally textured metaballs.
I spent alot of time playing with the settings on this one,
finally getting one i liked after changing the fractal noise
settings, the color, and adding a rather strong Fractal Bumps
point, I noticed the width of the voxels was making them 'poke
through' the tube of the LAW. I went back and made a specific
colission object for the LAW with the walls of the tube much
thicker... basically thicker than my intended size setting for
the hypervoxel elements. Once I did this, and re-recorded the
Particle Storm displacement files and reloaded them, the 'poking
through' effect stopped.
smoke object click for larger image
same point, I also became dissatisfied with the way the smoke
spread out as it exited the read of the tube. I made a tuncated
cone as an emitter object and placed it at the rear of the launch
tube in Particle Storm, parented to the motion of the tubee
in Layout, and had it emit a spread of particles while the particles
were coming from the rear of the tube. ( in the particle storm
setup image above, the fire is visible as red particles, the
original smoke as white particles, and the added smoke as light
blue particles) once these particles were added to the scene
and i copied the smoke settings from the other set of smoke
particles, it produced a more satisfying effect.
for a larger image or click
here for an AVI
above, the effect still requires a bit of tweaking before it
becomes completely passable, but is still satisfying overall.
is a freelance writer, animator, illustrator and production
designer based out of Richmond, Virginia. He can be reached
at [email protected]