#Framebuffers
6 messages in this thread
I have been thinking of upgrading my graphics card and have been hearing
the term "framebuffer" used. Where in the operation of 3d studio does
the lack of a framebuffer become apparent? When is a graphics card a
framebuffer? When is it not a framebuffer? How do I know when I buy a
graphics card whether it is a "framebuffer"? I would greatly appreciate
any light you could shed on this matter. Thanks,
J.F.
Hi Joe.
A frame buffer is a video card that actually loads the pixels into its on board
memory. Many frame buffer cards (i.e. Targa+, AIVista) have RGB, NTSC output
that allows you to view the rendered (or otherwise acquired) frame on a video
monitor, as opposed to a VGA monitor. That way you can check for color
correctness before laying your animation onto tape. One of the other features
that set frame buffers apart from regular video cards is the price. We're
talking $1300 to $3000 (there's probably even more expensive cards out there),
and you get what you pay for.
^.^ jt
In addition to John's excellent reply, a framebuffer typically displays its
images on a second monitor. Thus, when you render a scene in 3D Studio, it
appears (and stays) on the second monitor — or framebuffer. You can then
examine the scene while using the 3D Studio interface on your main display.
– Jack
Thanks for the quick response, but I still have a couple questions.
I have literature from Matrox and Targa describing a variety of
their products. Not one of them is described as a "framebuffer". I
can buy an ATI card with 2 or 3 Mgs of ram, does that make it a
"framebuffer"? I can put two Matrox Hiper cards in my box and probably
render to two monitors. Add a $300 vga to NTSC card and I can see it
on tv, maybe. I can spend $1300 on a graphics card (which I am
prepared to do) but since none of the cards are advertised as
"framebuffers" how do I know when I have bought one?? Is it simply
the ability to render to a second monitor? or is it the RAM? or is
it the fact that you can see the rendered image on NTSC? Or is it
all of the above(my guess!!). thanks for the input. I hope that
soon I will be able get to the bottom of this and start buying
something.
J.F.
Framebuffer is a graphics workstation (big ol'computing "thing") term. Those
systems usually only had TTY capability (plain text mode like when you do a DIR
in your computer). In order to display an image, they had to add special
hardware to "hold" and display the image. It doesn't really make much sense
when it comes to a PC (not the MAC though but that's another weirdness all
together).
You shouldn't care about that term. First define what you need. Do you need to
have the output going to tape? Or is it just to display in your VGA screen. If
it's going to tape, will it be necessary to have high quality (so called
broadcast quality) or not so much high?
If it's broadcast quality you need, then you will want a Truevision VISTA or
even a Truevision Targa Plus. Those are "secondary" display hardware. The
output you get from them (Composite, S-Video or RGB) are good enough to drive
broadcast quality signals into a frame accurate VTR or Laser Disk. You will
still need a "normal" VGA for your day-to-day work (and 3DS user interface as
well).
If you don't care about broadcast quality and playing an 8 bit FLC will do it,
then you want a Super VGA card capable of outputing NTSC signal. I know almost
nothing about this but I'm sure a lot of people here do. I've heard of a
"Magni" VGA but that's all I know. In this case, this "VGA" card will work
alone in the system. It will display both user interface and final image on the
same monitor.
Yet another option is not worring at all about display. Just use your VGA for
user-interface (and preferably a 24 bit one so you can "check" the resulting
image) and render the images to disk. Dump those images onto a tape and send it
over to somebody who has a $4k Vista or a $1k Targa to render to disk/tape for
you.
Thanks for information! I think my next stop is to talk to the
Truevision and Matrox people now that I have a better idea what
kind of questions to ask. thanks.
J.F.