Path: utzoo!utgpu!watmath!att!pacbell!well!shf
From: shf@well.UUCP (Stuart H. Ferguson)
Newsgroups: comp.sys.amiga
Subject: Re: 3D Applications
Message-ID: <13042@well.UUCP>
Date: 7 Aug 89 07:40:35 GMT
References: <4288@amiga.UUCP>
Reply-To: shf@well.UUCP (Stuart H. Ferguson)
Organization: The Blue Planet
Lines: 162

+---- Jimm Mackraz says:
| There are some things I've been thinking about for 3D applications.
| I don't own any 3D tools, and wonder which would be most applicable.

Interesting ideas here, Jimm.  I'll respond, since I know a little about
3D on the Amiga.

| Application 1: Low-end architectural walk-throughs.
   [ ... ]
| Take this scenario: Interior contractor/designer is trying to help
| Joe Schmoe decide on some big changes to his kitchen.  [ ... ]
| 
| Contractor takes copy of rough plans, on Friday, over to Self-Employed
| Amiga Person (or, Seap).  [ ... ]
| Monday, the contractor picks up a video tape (a key point) and shuttles
| it over to Joe Schmoe's home, which certainly has a VCR.  Tape has
| some animated rendering of the kitchen, at different times of day,
| with a moving camera.  Renderings are rough, since there was only a weekend.
| At a few points in the tape the camera freezes, and a ray-trace/texture mapped
| still-shot replaces the freeze frame.
   [ ... ]
| Is it realistic to hope that the model setup time could be short,
| but the rendering and subsequent recording might go on all weekend?

A weekend might be pushing it a bit.  First of all, making models is a time
consuming process no matter how you go about it.  Blueprints help, but the
layout could easily take a day or more.  And how much detail do you want?
Getting the rough shape right might only take a few hours, but getting enough 
detail to make it look good could take much longer.  In general, detail
is what takes the most time when modeling, and is what makes the most
difference to how good something looks when rendered.

Of course, the other part of the equation is that the more detail you add, 
the longer it takes to render.  Ray tracer rendering times are usually
measured in hours, sometimes days, depending on the detail of the model,
number and type of lightsources, and the speed of the processor.  The nice
thing about the Amiga is that you can render while you continue to model,
which can save a lot in terms of clock time.  The only program with a hope
of generating enough animation to be useful with the detail required would
be VideoScape 3D (plug, plug), whose frame rendering times are measured in 
minutes, not hours.  With a frame time of 10-15 minutes, you could get 
200-300 frames in 48 hours.  This would be 7-10 seconds of full video 
animation (30 fps), or maybe a minute or two at a lower (but still 
respectable) frame rate.

Another problem, which could make the process a lot more expensive and time
consuming, is how to get the Amiga animation on videotape.  Single frame
videotape equipment costs $6-10K and will substantially increase preparation
time.  Videodisc equipment will record faster, but the quality is not as
good and the machine will set you back $12-15K.  (These my personal 
observations from a few years ago.  The technology may have changed since 
then, but I'll bet I'm still in the ballpark.)

A much less expensive way to transfer the animation would just be to record 
it as an ANIM and play it back with the VCR running.  This works pretty well
and with a good VCR you can do decent cuts without getting too much snow.
The problem is that since these are interior views with a moving camera,
there will be a lot of change from frame to frame and ANIM compression will 
not do much good.  The ANIM may tend to play back rather jerkily, although
an '020 and 32-bit ram will help a lot.

| I think that it should be TRIVIAL to lay out most rooms, esp.
| living rooms, once a healthy collection of objects is in place.
| The SEAP might even strike a deal for a contractor to help subsidize
| building a shape/color/texture database for their standard lines
| of cabinets, appliances and furniture.

Yes, this kind of preparatory work will save a lot of time when the heat's
on.

|  [ ... ]  Could you design
| a table to real physical inches in today's modelers, or is that
| too much a CAD thing?

Not at all.  In Modeler 3D (plug, plug) you can construct scale models
very easily, provided you can work in metric units.  I know of some users
who have entered blueprints almost directly into Modeler.  In fact, for his
Siggraph film "Rush Hour," Allen Hastings encoded the entire Golden Gate Bridge
at  three different levels of detail (for viewing at different distances),
using the original engineering diagrams.  I don't know how long it took him, 
but the main model is accurate to centimeters.

| The impact of a video tape would be prominent.  A furniture dealer
| had somebody make us a sketch of a chair with a particular fabric.
| If both fabric and chair shape were in a database (or easy to
| generate), why wouldn't it have been just as easy (cheap) to
| hand us a video tape of a various views of the chair with several
| different fabrics?

It would certainly be cheaper and quicker to make a series of stills rather 
than an animation.  What might be more expensive, but more useful, would
be to allow the customer to interact with the designer and the SEAP to do
some real-time "what if" scenarios.  With rendering times on the order of
10-15 minutes, this might be realistic, although it would really put the 
pressure on the SEAP, and a Guru or two would really kill the momentum.
The other option is as you suggest, to do the "what if's" in batches and let
the customer interact with those to come up with another batch for the
next weekend.

| And for a room with lighting issues, it would
| be even more dramatic.

This is another problem.  Rendering software for the Amiga today (or for
any machine, for that matter) does not do a great job modeling lighting
effects.  You can get interesting looking results with the current crop,
but they are not necessarily realistic.  To make images with even a hope 
of capturing the subtle lighting effects of real room interiors, you 
would need something more like radiosity.  Since there aren't any 
radiosity programs for the Amiga, I can't guess how long it would take
to run one.

| Application 2: Presentations and Tutorials
| 
| Is there a simple business graphics package that can feed the rendering/ray-
| tracing tools?

Don't know.  If the BGP's format is public, it would probably not be much
effort to convert it to one of the documented 3D formats.

|  [ ... ] How about
| a 3D tutorial animation, such as for, say, a 3D modeler?  I saw something
| Leo made of a camera moving around an object with a moving light source.
| Little coordinate system, etc.

Yeah, that was cute.  Leo was trying to show how he made the lightsource
APPEAR to move (since VideoScape doesn't provide moving lights) by moving
both the object and the camera and using a static background.  It would
be much nicer, again, if there were interactive tools that let you design
your motions that way.

| What are the applications that Amiga 3D stuff is getting, REAL WORLD,
| besides TV, logos, and 3D text?  Any of it paying off?

"T.V." is a big category to exclude.  I know that flying logos aren't
very exciting, but I've seen some Amiga stuff used in inovative ways.  There
was a guy using VideoScape for a bass fishing program on a cable channel.
His did the titles with it, but also animated some sequences showing where
people would be fishing by flying over a lake model with trees and cabins
around the edge.

Bob Petersen uses VS/Modeler in his work to recreate traffic accidents.
He constructs intersections (probably using a set of generic parts) and
then moves the cars through them at different speeds and locations, and
makes animations showing both bird's eye views and views from within each
of the vehicles.  There was one really inpressive sequence where he had 
recorded a real view out the window of a car and then faded from that to
a VideoScape view out the same window with the scenery going by at the
same speed.  That was quite cool.  He has a whole video studio behind him,
however.

I'm not trying to say it would be impossible to do what you suggest, just
that it wouldn't be trivial.  The set of 3D graphics tools for the Amiga
appear, at least for now, to be superior to the equally priced tools for
other computers.  Hopefully we can keep that edge and hone it fine.

| I just noticed that my little reminder diagram of an Exec list could
| use improvements.

Do it.
-- 
		Stuart Ferguson		(shf@well.UUCP)
		Action by HAVOC