possible?

[David Beckwith]

Just curious.

Does Cinema 4D use OpenGL under the hood?

http://www.youtube.com/watch?v=KJSOsyImbF0

Is it possible to make an app like Cinema 4D with penumbra? Would you
want to?

D :)

[ztellman]

I'm not familiar with that particular piece of software, but most
commercial rendering packages only use the graphics card for
previewing your scene, and use some variant of ray tracing [1] for the
final render. There are a lot of reasons for this, but mostly it has
to do with rasterization (the approach used by graphics cards) not
being very good at realistic lighting.

There has been talk of hardware accelerated ray tracing for pretty
much forever [2], though, and it might actually turn into something
real eventually. [3] The resulting API would probably look more like
OpenCL than OpenGL, but a bridge between the two would certainly
exist.

[1] http://en.wikipedia.org/wiki/Ray_tracing_(graphics)
[2] http://en.wikipedia.org/wiki/Larrabee_(microarchitecture)
[3] http://www.tomshardware.com/news/wolfenstein-ray-tracing-knights-ferry,11282.html

[David Beckwith]

This is 188 kB for a 1024x768 screenshot of Wolfenstein:

http://tinyurl.com/29x5xkt

To get 50 frames per second, you would need 50*188 = 9400 kB = 9.4 MB
per second of bandwidth. In kilobits, that would be 75,000 kb/s.

Not sure how much bandwidth would be required to update the moving
polygons. The static scene is a 1 time download, and sending camera
position and orientation info is not that expensive. Sending movement
updates might not be too bad if you could parameterize it.

So as a rough estimate, I would say that if you had a 75,000 kbps
connection it might be doable. I think with comcast I get about
10,000 kbps, so if I were to use that I could probably be able to play
on a (320 X 240) screen. Hehe.

D :)

[Tobias Krumholz]

For realtime rendering bandwidth is not your problem. Let's say you
constantly change
your direction in Wolfenstein.
You press a key on the keyboard.
That key gets send to the network and takes about 50 ms.
The server has to process your key press and alter what is rendered on
your screen
accordingly. The answer from the server takes another 50 ms seconds to
reach you.
That means from the moment you press a key and see your character on
the screen
move accordingly there is a at least 100 ms delay. Input will feel
delayed like that.
It sure is not impossible but it is a very difficult task.

Tobias Krumholz

> > [3]http://www.tomshardware.com/news/wolfenstein-ray-tracing-knights-ferr...

[David Beckwith]

I can imagine latency to be a big problem, but then again remember
when Google maps first came out?

It was like you could scrolling forever and ever without any apparent
delay. (Well, if you scrolled like a grandpa.) Google maps created
the illusion of 0 latency thanks to this technique known as caching.
Who would have thought, caching could create such a wonderful
illusion? Maybe (*maybe*) with some intelligent caching techniques, a
similarly wonderful illusion could be created with Wolfenstein?

I agree. It's a hard problem. . . . . but fun! And what if we could
pull it off: solve that hard problem and create the illusion that
nobody else dared to?

David :)