27 replies to this topic

[chairmonkey4406]

I hear people talking about vector graphics all the time. What is it? How does it work? How is it any different from any other graphics? Thanks.

[CPUWIZ]

Google dude !

http://www.design-wo...er_graphics.htm

[JB]

"For Dummies" version:
A raster display works like a LightBrite. You have discrete dots(pixels) that can be set to specific values, and a picture is made by setting these dots to various values, similar to the way a color picture in the newspaper is made.

A vector display works like an Etch-A-Sketch. There's a "pen" in the form of an electron beam that's moved around to draw an image directly on the screen.


The advantage to raster displays is that the electron beam used to stimulate the phosphor pixels moves the same way each time, so the screen draw time is constant. Draw time on a vector display goes up with image complexity, eventually causing slowdown(as the draw time starts to exceed the alloted frame time and flicker(as the draw time starts to exceed the phosphor persistance time).

The advantage to vector displays is that a computer only has to track a set of points. Instead of making an entire image, the computer just stores the endpoints to the lines. Consequently, it can work with more and higher resolution objects at once. Scaling and rotation effects are also easier since it's working on maybe a dozen points at a time instead of 64(for an 8*8 sprite) or more.



Vector displays also offer certain image properties that make them diffrent, but not better.

Since the electron beam only passes over phosphors that are supposed to be lit for the most part, black parts of the image are a true black instead of faint gray. And the lit parts of the screen are brighter too. Makes for a very vivid image.

And speaking of lines, vector hardware only makes straight lines of varying lengths. Curves are evil, as are filled objects.
If you want to see what NOT to do with a vector display, I urge you to look at the arcade game Quantum.
But these lines are perfectly straight and drawn straight to the screen, so the aliasing problems present in other games due to the conversion to discrete pixels(most notably modern polygon games, though it's present in all raster games) is non-existant.

[Fellow Atari Man]

...and a REAL simple way to explain the difference is raster graphics are made up of the squares on your tv, whereas for the straight line of vector graphics...well, just look at my avatar, for instance

[Hydian]

As far as from a graphical standpoint, raster graphics are defined pixel by pixel while vector graphics are defined mathamatically. This means that vector graphics never get blocky as you scale up or down and are generally a smaller file format.

Programs such as Corel Draw and Adobe Illustrator are vector graphics programs. Programs such as adobe photoshop are raster graphics programs.

Personally, when I was playing around with graphics (years ago) I really liked working with vector based stuff.

[JB]

Fellow Atari Man said:

...and a REAL simple way to explain the difference is raster graphics are made up of the squares on your tv, whereas for the straight line of vector graphics...well, just look at my avatar, for instance

Whoops!

I started with a simple explanation, and then launched into someting more complex without a seperator. BAD ME!

So yeah...
Vector = Etch-A-Sketch.
Raster = LightBrite.
Example = lame, but workable.


...



Why do Photoshop and Illustrator keep coming up? One would assume a question asked in the classic gaming forum would be looking for the definition as it pertains to classic games.

[Hydian]

How the graphics are put together is as pertinant as the differences between screen types IMHO. Knowing that a vector screen only draws the lines still doesn't explain *how* the graphics are different.

[Ze_ro]

One of the big advantages of vector displays was that things like scaling and rotation were super easy. Since you're only talking about 3 or 4 lines forming a triangular space ship, you can easily just change the point spacing to make the ship bigger, or perform a few sine/cosine calculations to spin it around, and best of all, you will never get any pixellation, ever (although vector displays have their own issues, like beam width and flicker, which was already mentioned). Doing this on a raster display is a lot more intensive, and usually results in massive pixellation. You can pull off some fairly impressive 3D effects on a system as old as the Vectrex that would have been impossible on the best raster systems of the time.

Of course, that was 20 years ago... now that we have 3D cards that do all this texture mapping and stuff, this advantage is completely gone. Vector displays are generally limited to white-on-black pictures, so complex graphics are very difficult, and you're often stuck with monochrome. Color vector monitors exist (Tempest in the arcades, for example), but they're expensive, and you're still stick with fairly simple graphics. Doing something like Sonic the Hedgehog with vector graphics wouldn't look nearly as good.

--Zero

[desiv]

Quote

Why do Photoshop and Illustrator keep coming up? One would assume a question asked in the classic gaming forum would be looking for the definition as it pertains to classic games.

OK, how bout this...
Think Apple II series...

Blazing Paddles is a bitmapped Raster drawing program.
Fantavision is a VECTOR based program (albeit for a RASTER system).

desiv

They might not be games to some people, but to me they were.
And they ARE classic!!
:-)

[JB]

Hydian said:

How the graphics are put together is as pertinant as the differences between screen types IMHO.  Knowing that a vector screen only draws the lines still doesn't explain *how* the graphics are different.

Sure it does.
In my opinion it really is as simple as "vector screens draw lines, and raster screens light up a grid of pixels".


And I'm not really sure that the same definition applies for video displays as imaging programs.

[desiv]

Quote

Sure it does.
In my opinion it really is as simple as "vector screens draw lines, and raster screens light up a grid of pixels".

Of course, a Vector screen can draw raster images also..

YASI on the Vectrex is an example of this...

And Raster screens can draw lines.

So it can still be confusing to someone.

They see YASI on the Vectrex and Asteroids (MAME - HiRes) on the PC and say... "what's the difference..?"

And remember, with all those rods and cones, we actually see with pixels..

Vector monitors were chosen for the function, speed and price at the time.
Raster monitors were chosen for the function, speed and price at the time.

They both use the same tube/gun methodology. It's the logic behind that which is important.

If you just say it's about lines, YASI and I, ROBOT might confuse people..

desiv

But.. You're right. It's mostly about lines.. :-)

[Fellow Atari Man]

JB said:

Fellow Atari Man said:

...and a REAL simple way to explain the difference is raster graphics are made up of the squares on your tv, whereas for the straight line of vector graphics...well, just look at my avatar, for instance

Whoops!

I started with a simple explanation, and then launched into someting more complex without a seperator. BAD ME!

Hee hee, that's ok, getting carried away happens at times Kind of like if you want an answer to something, I'd ask my sister. But if you want a lecture when he THINKS he's answering your question, ask my dad the same question (insert exploding head icon here)

Hydian wrote:

How the graphics are put together is as pertinant as the differences between screen types IMHO. Knowing that a vector screen only draws the lines still doesn't explain *how* the graphics are different.

Well, as was mentioned before, Sonic the Hedgehog's raster, and several late 70s to 80s games were vector: Asteroids, Tempest, Gravitar, Lunar Lander, Star Wars (in many people's opinion, THE best vector game ever), Battlezone, etc. Everything is drawn as lines with those games.

[NE146]

And don't forget my favorite Vector thingy.. the BRIGHT shots in Asteroids You can't do that in a raster display.. and that's make one single pixel much more brighter than any other on screen object. And by bright I mean bright to the point where it radiates out of the screen to the point where it creates a halo effect on the monitor. If you tried that on a raster display, everything else would have to get brighter as well.

[Bryan]

To be technically correct, a vector monitor is not limited to straight lines. The X and Y inputs are analog and can be fed with sine waves or whatever. The big difference is that there are X and Y inputs, so the beam can be positioned anywhere, anytime.

-Bry

[Hydian]

Right, it is not limited to straight lines at all as the formula used to generate the graphic can just as eaily be a curve. Oscilliscopes are vector displays. The lasers at a laser show work in the same general fashion too.

[JB]

NE146 said:

And don't forget my favorite Vector thingy.. the BRIGHT shots in Asteroids You can't do that in a raster display.. and that's make one single pixel much more brighter than any other on screen object. And by bright I mean bright to the point where it radiates out of the screen to the point where it creates a halo effect on the monitor. If you tried that on a raster display, everything else would have to get brighter as well.

I DID mention the awesome contrast.

[Rob Mitchell]

bryede said:

.. so the beam can be positioned anywhere, anytime.

So the Vector beam can jump over here and draw a space ship and then jump somewhere else and draw an asteroid.

Raster graphics have the electron beam scanning the whole screen and lighting up the pixels.

In mathematics a vector has both direction and magnitude. In Vector graphics programming the vector electron beam has direction and time for which it is drawn which determines its length.

You can only experience true vector graphics at a retroarcade or the Vectrex. Others? Emulation gives you an idea of what is happening.

Rob Mitchell, Atlanta, GA

[DracIsBack]

Bitmap graphics are derived from pixels on the screen. They look good but can be large and tend to get blocky if expanded.

Vector graphics were invented (initially) to reduce the size of graphics files and create a format where the graphics could be scaled without the loss of resolution. Whereas bitmap graphics are based upon pixels, vector graphics are based upon mathematical equations.

Examples of bitmap editing programs:

Adobe Photoshop, Corel PHOTO-PAINT, Jasc Paintshop Pro, uLead PhotoImpact, Corel PAINTER, Macromedia Fireworks

Examples of vector illustration programs:

CorelDRAW, Adobe Illustrator, Macromedia Freehand, Micrografx Designer.

Hybrid types that combine both (to varying degrees of success): Xara, Deneba Canvas.

Hope this helps.

[Ze_ro]

desiv said:

Of course, a Vector screen can draw raster images also..

Yes, but that's defeating the whole purpose of having a vector monitor to begin with. Plus, it makes the programming more difficult since you have to do all the raster effects yourself.

YASI does raster graphics on the Vectrex, but it's a little odd when you see it... things sort of jitter around and such. It would have been much simpler to draw each alien with a few lines, but I guess that really wasn't the look that the programmer was going for.

bryede said:

To be technically correct, a vector monitor is not limited to straight lines.

No, but the video driver usually is. Back in the 80's, I don't think there were many systems that could calculate bezier curves or interpolate splines quick enough to actually do them every 1/60th of a second.

It would be interesting to see a more modern system with a vector display... it could be VERY impressive.

You really have to see the difference between raster and vector graphics firsthand to really understand how they look... descriptions really don't help that much (and talking about Illustrator and stuff doesn't really give you any idea at all about how it actually looks). Try playing some of the raster games in MAME and you might get an idea.. although since your PC's monitor is a raster display, it won't be quite as good as the real thing, but it's a start.

--Zero

[Bryan]

Ze_ro said:

It would be interesting to see a more modern system with a vector display... it could be VERY impressive.

I thought about making a PCI card for driving a vector monitor. It would be fun to experiment with.

-Bry

[Room 34]

I understood the difference between vector and raster graphics, but I never quite understood how a vector DISPLAY works until I read this thread. Thanks for the info, guys!

BTW, there really is no way to appreciate the qualities of a vector display in emulation on a raster screen. It makes me cherish my Asteroids cocktail table even more! (The brightness of the shots, etc. really IS pretty amazing.)

[neotokeo2001]

Example:

Original Atari 2600 Donkey Kong


Simulated Vector Graphics Hack:
http://atariage.com/...ad.php?id=17249

[Albert]

Room 34 said:

I understood the difference between vector and raster graphics, but I never quite understood how a vector DISPLAY works until I read this thread.  Thanks for the info, guys!

I'd like to second this, lots of great information in this thread.

..Al

[KaineMaxwell]

Is that part of the reasons why Tempest machines break down alot as well?

[bjk7382]

If you really want some specific info about vector graphics, you should take a look at the Instruction Manual for the arcade game Star Castle. It explains a lot of this in great detail, it even tells the repairmen how to fix it.

Sorry it is only in PDF
http://www.arcadedoc.../StarCastle.pdf