Dithering Pattterns

[kobayashi]

Has anyone else discovered that if you try to make the dither pattern blank the results are strange dither patterns created by the computer - like random straight lines.

Also that you choose colours for the dither dots (usually black). The result is also unpredictable.

 

[oryx]

I've replaced the black dots with 50% gray dots. Sometimes this improves the appearance of the terrain tiles. This depends of course on the terrain tiles.

I've never left it blank.

 

[Marko]

I met the problem when I made winter terrain for TSFE. There are two kinds of hills: snow-covered for Europe and without snow for Africa. I wanted to blank out the dithering but met the same problem as you.

I haven't tried to change the dithering colour. It sounds interesting. Maybe it is possible to create special graphic effects for scenarios when changing some aspects of dithering

 

[Morten Blaabjerg]

The trick with blanking out the dither pattern, is to leave just a couple of black pixels, and it will work. If you leave a black pixel in each end of the square, its practically blanked, and terrains etc won't be dithered, except for those few pixels. The downside to removing the dithering is that terrains that are very different from the coastline colours won't blend in with the coastline, making it look a tad blocky and out of place.

 

[Eyn]

sorry my english is not very good
maybe i'm wrong but are u speaking of delete the "mixed" pixels of the terrains squares ?

like this ? (MGE version)

or this (ToT version)

for ToT there's a little problem, Terrain must stay in it "base square", MGE terrains can oversize the upper side of the "base" square"

 

[Eyn]

ToT terrain can't oversize it's "base square"... except for bonus terrains

 

[kobayashi]

After some experimentation, I found out you need a minimum of EIGHT dots to avoid the unexpected effects.

Nice picture Eyn.

 

[Eyn]

the terrain1 "dither" case of my scenario Mafia (the 2 screenshot i post) have no black dots !

 

[Morten Blaabjerg]

Originally posted by kobayashi
After some experimentation, I found out you need a minimum of EIGHT dots to avoid the unexpected effects.

OK. I remember I did end up with more than just two pixels to make it look nicer, but didn't check.

 

[kobayashi]

Originally posted by Eyn
the terrain1 "dither" case of my scenario Mafia (the 2 screenshot i post) have no black dots !

but what did you do to get no black dots?

(seem to be some white dots though unless those were added purposely)

 

[Eyn]

honestly... i don't know !

i just remember i've made lots and lots tests before i succeed to have "clean" terrain types without any "mixed" sprites

the strange thing is the difference between ToT and MGE as i've say in my previous messages.

 

[Eyn]

yes as u can see there's some white, yellows or red bug pixels but they stand on the "ocean" not the ground terrains maybe i've not change as it should be the "ocean" terrain2 tiles

 

[Allard HS]

I did some extensive testing on this subject for my RiverWar scenario. If anyone noticed, I added a lot of dithering dots there with the effect to make all terrain a bit smoother. The only terrain that doesn't work as well as the others is the grassland terrain. With too many dots the grassland will cause strange horizontal lines to show up, which was mentioned earlier in this thread i believe.

Anyway, if you remove the entire dithering square, the whole map will be full with those horizontal lines. For some reason, though, this is only the case if you make it all purple (palette no 253 if I am correct). If the pink background colour is used, it does work as it should.
I don't remember the exact details anymore by heart, whether you should retain the diamond form or not, but this should work. Otherwise, have a look at my RiverWar scenario and try adding some dots and removing them.

 

[Eyn]

... the white, yellows or red ocean bug pixels was due to some mistakes with the ocean tiles of terrain2 file

i've updated it and as u can see now on the 2 screenshots, these visual bugs didn't appears anymore !

need to update my scenario zip file now.

 

[The ANZAC]

I'm sorry, but I read, but I still can't figure out what exactly dithering is and what its effects are. Could someone explain?

 

[Mercator]

This is what they're talking about (see the attached image)...

It's the pattern used to control how smoothly adjacent terrain squares overlap at the edges.

EDIT: ALLARD!! You're alive! :jump:

 

[Allard HS]

Ok, I'll explain the trick.

Using the pink normally 'invisible' background doesn't prove to be that invisible after all. As you can see, it works well in that the squares are indeed square without dithering overlaps.
However, all grassland squares do not follow the rules and strange horizontal lines will appear.

 

[Allard HS]

If we delete all the pink altogether and leave the whole icon with the grey/purple (depending on what colour palette you choose, anyway the last colour of the palette) completely, it will look nice and neat, and no horizontal lines are visible.
This is what we want.

Note that if you use the pink completely in the square, grassland squares will kind of 'turn around'. Can't explain this really, test it for yourself.

 

[Allard HS]

You can do more fun things by adding more dithering. (watch out.. not too much or it will go bad again).

This example as I used in RiverWar shows a more natural terrain where the individual squares are less distinctive and more or less blend together, which gives a nice effect especially in desert-like terrains where all looks a lot like each other.

 

[Allard HS]

Some more useful info having somewhat to do with this, and may have been the cause for Eyn's trouble with his pixels between the squares is here.

http://apolyton.net/forums/showthread.php?s=&threadid=10312