Adventure Game Studio

AGS Support => Advanced Technical Forum => Topic started by: Vel on Wed 12/03/2003 18:58:00

Title: Suggestion: Anti-aliasing for non-scaled characters
Post by: Vel on Wed 12/03/2003 18:58:00
Wouldn't it be nice if there was an option to anti-alias non-scaled characters? This may improve the style of many games and blur the horrible outlines.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: danny* on Wed 12/03/2003 19:21:26
that would be nice... :)
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Synthetique on Wed 12/03/2003 20:41:15
couldnt that be done using two characters in one? one at top and another with that particular color between pixels in every corner, with set opacity 30 ... or something?
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: scotch on Wed 12/03/2003 21:54:51
I don't get it, at 100% your characters should be fully antialiased the way you drew them.  If you mean antialiasing the edges, ie the transparency then you'd need to be able to have different levels of tranparency and alpha blending.  The scaling antialiasing doesn't do that, it only blends pixels as they get scalled down so you don't loose pixel details, they just fade into each other.
I think the reason the ags characters don't have alpha channels atm is due to speed, the wintermute engine does it, but that uses 3d hardware :(
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Pumaman on Wed 12/03/2003 22:12:41
I think scotch has explained it well.

Basically, the anti-aliasing smooths the resize by blending the pixels together. If you draw the image at its normal size you won't get any effect from anti-aliasing.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Relight on Thu 13/03/2003 19:16:31
I'm not sure if it would work, but you could try just making your walkable area 99%.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: scotch on Thu 13/03/2003 20:19:21
It would use the antialiasing, yes.  But it would probably look a little worse than at 100% The scaling antialiasing only makes the interior pixels of characters blend with each other rather than missing pixels out like it usually would, it doesn't make characters look better then they did at full scale, just stops your nicely drawn characters from looking wierd with eyes dissapearing etc.  At 99% the effect wouldn't really be noticable anyway.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Trapezoid on Thu 13/03/2003 21:23:22
OK, here's an explanation of what the scaling antialiasing does.

Picture an object which is 2 by 2 px... It's a black and white checkerboard pattern (two blacks and two whites)
If you scale it down to half size without anti aliasing, it would be 1 pixel of either black or white.
But if you scale it down WITH anti aliasing, it would become one pixel of midtone gray. Because instead of systematically erasing rows and columns of pixels as they shrink, it MIXES them. Nothing goes on to mix the sprite's outer edges with the scene's background.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Pumaman on Thu 13/03/2003 21:33:47
Nice work guys, good explanations. I hope this has answered your question Vel, and anyone else who was curious.

There is a further use of antialiasing, which modern graphics cards can do - "FSAA", or Full Screen Anti Aliasing. In its simplest form, this involves creating a double size copy of the entire screen, then shrinking it back down with anti-aliasing, before drawing each frame. This allows the entire screen to have the anti-aliasing effect, but can cause blurriness depending on how it is applied.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: scotch on Thu 13/03/2003 21:35:10
I think it would have been better to call it sprite filtering or resampling :)
Antialiasing people associate with smoothing edges, this is more similar to texture filtering in 3d I think, or the resampling (bicubic, bilinear) when you scale up and down in photoshop or psp.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Vel on Thu 13/03/2003 21:52:28
Yes, but what do these options in newer Adventure games actually do? They antialias The characters without scaling them.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: scotch on Thu 13/03/2003 22:05:36
Yes, that's why I think this antialiasing needs a different name.
The antialiasing you're talking about is done with alpha transparency in 2d images, or full scene anti aliasing in games with 3d characters.

AGS doesn't do either of these, it just means cahracters don't degrade in quality when they scale.
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Czar on Thu 13/03/2003 22:21:59
But is good for showoff  ;D
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: on Wed 30/04/2003 13:59:27
32 bit colour sprits would be nice. Is AGS lack of 32 bit images support due to speed or is it just not on "the list" of things to ad?
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: scotch on Wed 30/04/2003 14:09:38
Probablt speed,  I mean 32 bit, with alpha blending and stuff would be very slow in a software rendering program like AGS, unless AGS changes radically and supports 3d hardware accel I don't think it's going to happen soon..
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Gilbert on Fri 02/05/2003 03:48:00
Because back in the old time, there was a poll on whether hicolour or 24/32 bit truecolour modes be added to AGS, and the result was "hicolour rulez!1!".
And due to speed/memory/effort/etc concerns, truecolour support will not be added unless there're popular request or some good enough reasons for it.

(I won't care as 256 colour modes are enough to me already...)
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Igor on Fri 02/05/2003 09:35:00
I think hicolor is more than enough for any game out there- you don't have problems with palettes (as with 256 mode) and only the author of picture/background can usualy see the quality difference between hi-color and true-color pic. So, i don't think the "better" quality of true-color would really justify the speed slow down and bigger file size.
That said, 3d hardware acceleration would still be nice :)
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: jannar85 on Fri 02/05/2003 11:00:05
Here's where MY suggestion comes into use.
http://www.agsforums.com/yabb/index.php?board=2;action=display;threadid=4862;start=0

:)
Title: Re:Suggestion: Anti-aliasing for non-scaled characters
Post by: Pumaman on Fri 02/05/2003 14:18:52
24/32-bit colour has not been added because:

* truecolour bitmaps take up twice as much memory as hi-colour ones, greatly increased memory requirements
* there's twice as much graphic data to draw on the screen, which slows down the game

The only real advantage of using truecolour is that you get smoother gradients, but in all other respects it is very difficult to notice the difference between a picture at 32-bit and 16-bit.

I could add 32-bit support, but I just fear it would get over-used in games that really didn't need it at all, just slowing down the game for no good reason.