#Bones in LWPro
28 messages in this thread
Hi Ho:
John I was just wondering if you had any plans for a follow-up on Ken
Stranahans article on bones. I was working on a project this week, one I
thought would be a snap; Molded my model, made my object skeleton, created
my motion paths (a really outstanding jogging cycle, if I do say so
myself). But the one thing I forgot to check is the how the bones
interacted with the model. It was kind'a cool the way the polygons bunched
& shot all over the place. Anyway I think that bones are (is?) still a
very misunderstood area of LightWave. Considering how powerful this
feature is, I really think you need to do a little piece on it here and
there. I had to go back to issue 1 to find anything on bones.
I also noticed there is no mention of a class on bones in Hawaii. Do
you know if anyone who'll bee there would bee talking about it. It looks
like a pretty good line-up, minus that.
Hope I can buy you a beer on the beach…
Brad Hayes
H.V.C.
Brad,
FYI: Looks like Allen Hastings will be a last minute addition to the line-up of
LightWave experts in Hawaii. We are adding on a special session for him on
Thursday right after the last scheduled class. He will also participate in the
end-of-seminar Q&A with the other trainers.
Jim Plant Avid Publications
Hrmph,
What does he know!?
JG
I think Allen is planning on bringing his PC laptop to show some LightWave
stuff on the PC. He's pretty much open to discuss anything people bring up.
JP
How about the error in refraction drawing and index of refraction
handling!?!? Its been in there since rev 1.0 and no amount of bug
reporting/sample file shipping to NewTek et al seems to get any notice…
wmc – via Autopilot!
Wayne,
Actually, LightWave didn't have Ray traced refraction in V1.0. It wasn't
introduced until 2.0 and worked flawlessly at that point. subsequent
revisions (3.0, 3.1, 3.5) however, have had their share of buglets:
1. When many of LW's internal computations were converted to floating
point, a variable was missed and caused erroneous results.
2. Later, there was a bug that caused LW to ignore 1.0 mediums when coming
from a non-1.0 medium… the fix was to substitute 1.001 instead.
3. 3.5 fixed both of these, but a new bug was introduced which may cause
small black speckles to appear in the refracting surface. This is cuased
by the ray tracer getting confused when two faces share the same space (as
in a two sided polygon). This will be fixed in 4.0, but the temp fix now
is to create a minute gap between the inside and outside facing surfaces.
(or use 3.1 with indexes of 1.001 for the air surfaces).
Of course, you have to model objects correctly for refraction to work
properly. Make sure to always have a surface facing towards the ray of
light traveling through an object with the Refraction index of the
material that is being passed into. For an excellent guide to this, see
Understanding Refraction by Mark Thompson in the Oct issue of LWPRO.
(RSN)..
JG
John,
This is the old glass table problem I sent you the files for a while back.
The glass top is 1.5 inches thick. I have tried modelling that as a
simple box, with only outward facing polygons, (normals going into the
air) duping and flipping a copy to get a surface normals in each
direction, (going into the glass and into the air). I kept the simple
approach.
Now, the problem is that with a 1.5 IR, the distortion is orders of
magnitude off from what I see looking at the table in real life that I
modelled. (I ven measured my viewing position and set the camera
accordingly during one "trial". In order to get the rendered fram to look
like "real-life" I had to drop the glass IR to 1.01. And it appears the
same in every version of LW I've owned up to 3.5 (haven't tried it in 3.5
yet. Oops – that's not true – I didn't make the model until the first
"free" update to those who orignally paid like $1395 list for the Toaster,
but before 2.0.
Now regarding the bugs. How is air handled? The legs are sitting in
space (I have no model air in the scene). Is empty space RI 1.0? Is it
subject to the ignored 1.0 medium problem you mentioned? (Sounds stupid,
but I have obviously missed something as all LW Versions have given the
same erroneous result.) It sounds like, from your comment on 3.5 that I
have to create an "air box" around the glass table top with a pocket in
it, faces not quite touching, and face its normals into that glass, giving
it an IR of 1.001 and transparency 100%. Let me try that…
Holy Mackerel!!! That was it!! (LW 3.1 – My 3.5 is on another machine and
the net is not up at the moment. I'll try it there later). Sheesh! It
never dawned on me that I would have to model the air as well. Stupid!! I
just sorta assumed 'virtual reality' came with it pre-installed! Man!! So
dad-burned obvious and I've spent years 'in the dark'. &*^%$#@!!
Anyway, that leaves me with an enhancement request. Why not have a
"Universe" setting that defines your empty space with IR being one
element. That way whether its ocean, deep space, a liquid Nitogen
atmosphere or inside a glass paperweight you can set the objects'
environment to get the correct response for light passing through the
objects.
wmc – via Autopilot!
Wayne,
There's no need to model the air. For your glass top you have to have the
outward facing polys with a RI of glass and the inner facing polys with
the RI of 1.0 (or 1.001 in 3.1) Just imagine the ray of light traveling
thru the table: Everytime it meets a surface, the poly "facing" the ray
has to have a RI of the medium being entered into.
Hope this makes sense…
JG
John,
Thats what I meant by modelling the air – a poly (or object) at the
refractive surfaces with polys facing into the nexst medium and with
approp IR. Basically, since my table has rounded corners (36 polys on the
2" edge) and top and bottom surface, the easiest way to get the "air
polys) was to dup the table top, increase the size by 1.01 (you said, I
think, that 3.1 required a space between polys of media with different
IRs) then flipped the polys on the duped objec and created surface names
like [duh] Air. Then in LW set IR's appropreately.
Thats what I meant by "modelling" air. Any way it worked – and I feel
stupid since it makes sense (now) that I had nothing in the scene with a
1.0 IR. SO essentially it was trying to do a calsulation with a 0 and
depending on how he set it up, it could have been a Tan (0). Which
explains the large distortion I saw.
Anyway, thanks for the "bat up 'side the head bone…".
wmc – via Autopilot!
Sure, yep, you are doing it right, except that it is 3.5 that requires the
space. 3.1 requires the 1.0 of air to be set at 1.001 or similar since the
1.0 setting wasn't calculated correctly.
JG
John,
I got the 1.001 AND the space. Looks pretty good on 3.1 and from what you
say should look OK on 3.5 without any modification. Thanks again for the
"wake-up whack".
wmc – via Autopilot!
Jim,
I'm still looking for my September issue of LW Pro. Is this a problem, or
is it still enroute?
Thanks, Bruce
Bruce, The September LWPRO shipped the last week of September. Give it a few
more days before you call our office (1-800-322-2843). We ARE finally beginning
to catch up on LW PRO. The October issue went out to the printer today!
Jim
Jim, What about the disks? I still haven't rec the disk from the August (I
believe that was it with the candle holder on the front) issue.
thx
jmb
PMFJI,
The August issue didn't have a disk. July and September both do.
JGross
editor, LWPRO
JG, Maybe that is why I didn't get it.<G>
Logic!!!?? What!! Are you mad!!!
jmb
Jim, Received my LWPRO on around this last Thursday, thanks. I guess I'll
throw in my nickle's worth <inflation> of opinion on advertising. Once you
carry more advertising your advertisers become another group of customers along
with the subscribers. They will have certain needs and demands that will
probably affect the structure of LWPRO. But advertising may be necessary for
competitiveness over the long term. I guess I'm for advertising as long as it
remains disiplined towards accomplishing LWPRO's mission objective of
distributing info and expertise in LW3D and CGI in general. If advertising
revenue ever becomes an end in and of itself, well…
The additional resources and circulation should be an important help to
LW3D in the battle of the CGI softwares that may be on the horizon.
Finally, if it means more neat color CGI pictures, yes! :^)
Thanks, Bruce
Well, thank goodness I signed up for that extra day. This is going to be
the best write-off of the year…
Brad Hayes
H.V.C.
Yes,
We are planning on doing more bones stuff, I think Grant is covering some
bones stuff in Hawaii.
JG
>Yes,
>
>We are planning on doing more bones stuff, I think Grant is covering some
>bones stuff in Hawaii.
>
>JG
Hey…nice try :} I am already doing Displacement Mapping and Real World
Effects, and now picking up Brent's classes for Surfaces and Envelopes.
etc…NOW I'm doing bones too!!!? When am I supposed to see Hawaii!!!
grrr….this deal is getting worse by the day :}
Seriously, I do not think any of the classes are covering bones so
far…maybe we should, or discuss it in the roundtable?
Grant Boucher
1 of 2 Supervising Animators :} – Star Trek: Voyager – Amblin Imaging
Nooooooo, I'm leaveing before the round table. I'll have to get someone to
take notes.
And as for not haveing time to see Hawaii, I can't beleve I'll be there
for almost a week and not get to go Scuba Diving. Great, I'll be on a
tropical Island sitting in a confrence room watching computer stuff…
As long as I get a big drink in a hollow pinapple with little paper
umbrellas and a curly straw.
Brad Hayes
H.V.C.
A question about this Hawaii seminar to John or Grant…
I have attended LW seminars at Amiga expos in Pasedena, and I have taken a
few invaluable seminars with Lee Stranahan. After thanking Lee for all
the help I've received that has brought me to a certain level of
proficiency, I had to tell him that it would be my last one because of one
key factor: too much of the seminar time was taken up answering the most
rudimentary(!) questions by the attendees. This would not have been a
problem for me except that this was billed as an ADVANCED Lightwave
seminar. He acknowledged the problem and my frustration. I did get
something out of the seminar because I came armed with a list of advanced
questions to have answered, but I felt that I had to wrestle them in, not
against Lee's game plan so much, but against the level of discussion
persued by the majority in the room. So my question to you folks is, is
Hawaii where the professionals go to share insights on a professional
level? Or are all these commercial ventures geared to serve the lowest
common denominator? Please understand me, without the basic seminars to
take me from the beginning to where I am now, I don't think I would have
gotten here on my own. But I am looking for that truly ADVANCED seminar
where the people attending know what all the buttons do, and the thrust of
the content is in exploring the interesting combinations of those buttons
that we may not have thought of ourselves. (and when will this happen in
the New York area?)
Sean Hannon
Ad Rats – Stamford, CT
Avid has summaries of our seminars in hand…and that should answer your
questions about whether you will get much out of them. I personally doubt
a lot of beginners will fly to Hawaii to pay for the classes, so I expect
them to be more intermediate to advanced…maybe John or Jim Plant can
offer opinions…
Grant Boucher
1 of 2 Supervising Animators :} – Star Trek: Voyager – Amblin Imaging
Sean:
I certainly can not speak for every one who will be attending the
Hawaii dates. However I would conceder my self quite advanced in the use
of the Toaster and especialy with LightWave, I'v been using it daily since
Toaster 1.0. I have also attended Lees' classes here in Los Angeles, and
agree that the level of the curriculum was less advanced than I had hoped.
Each of the classes did provide invalubale in that I learned other unique
ways of organizing my thought process. I also now have several new
clients. I teach private Toaster classes, and consult with many companies.
I know that alone would certainly not convince you to fly from NY to the
other side of the Planet, but you will have an oppertunity to network with
others in your industry. I agree with Grant that I don't think you will
get a lot of hobbiests fly all the way out there.
Brad Hayes
H.V.C.
Sean,
These seminars are fundamentally different than the ones that Lee has taught
for us, in that these are shorter classes focusing on specific subjects. This
allows for more in-depth exploration of those subjects. The Hawaii seminar will
be similar to the training we held at Siggraph. With Grant, Tony, John and
Allen available for multiple days, you should have plenty of opportunities to
soak up so advanced LW information.
Jim Plant
Jim,
What per chance is the possiblity of these being taped and sold through VTU or
Rave?? Wish I could attend but no one believes me that this is where the pros
will be. They think I just want to go to Hawaii, God forbid.<G> I personally
don't think it would affect your ability to sell future classes but could be a
marketing tool for more seminars.
Just a thought
jmb
John,
We've given the matter some thought at various times since we started
sponsoring training. It probably won't happen in Hawaii. Maybe at the training
sessions at the VT EXPO in LA.
Jim Plant
Jim,
Since I won't be able to attend those, work to do, I look forward to purchasing
them.<G>
jmb