[CF-Devel] The truth about ISO gfx - or why you all are wrong

Sun Feb 18 08:16:45 CST 2001

Hi

I love this title - kick me for it.

Ok, i have read alot about iso gfx and iso style here
and i try to explain why things are different as some expect.

So, i make this mail and some demo gfx to SHOW you why things are
different as we do it in CF and why the CF png iso style is nonsense.

1. What is ISO gfx?

ISO gfx is NOT a 3D gfx. It is not drawn 3D perspective.
ISO style gfx is a eye trick. A way to fool yours eyes.

You THINK you see a natural perspective gfx - in real its a big fake.

It uses gfx tricks to fool you and tricks to make drawing gfx simple.

I will show you the interesting tricks.

2. Diablo and Age of Empire

Diablo and Age of Empire use both rectangle gfx turned for 90°.
This is only a way to attach in a easy way the tiles - i will show you
later why we don't need it.

Diablo 2 use not real ISO tile gfx. It uses "ISO parts", big rendered parts
which gets connected to a big picture. But int the core it is the same as
Age of Empire.

Age of Empires is one of the most sofisticated ISO bitmap tile engine which
is on market.
It has a map editor and i will show you the examples with it.

3. What ISO style bitmaps use?

a.) *nearly* FLAT BITMAP Objects!
b.) On all positions of a map objects of same *size*
c.) background gfx who fool the eye to think you see a perpective
d.) hidden "eye lines" in all object to fool your eyes to the perspective.

This brings me to the first big point:

The artist who native draw the CF png set don't know what iso style gfx are
and how it
works!

** We have NOT iso gfx in the png set - we have a bad frozen 3D gfx in it
!!**

Let me show you first picture (gfx from age of empire! microsoft copyright,
so beware)

This is simple grass with a few fighters.

     http://mids.student.utwente.nl/~michtoen/isodemo/demo1.png

As you can see, the 2 figures going the the right - THEY ARE *nearly* FLAT!!
The guy above is also flat, but the gfx has a animation on it, which turn
the figure
looking left to right. but the figure IS FLAT. The figure is drawn 'inside'
as a object
which look like propotions - thats all.

All figures are drawn flat from front!!

But as you can see, the pictures *without* any objects look real good - look
NOT flat.

why? Well, i will show you.

But first the funny part: Look this ...

     http://mids.student.utwente.nl/~michtoen/isodemo/demo2.png

Grin. Thats our ninja png ....

Now look at it. THATS WHY OUR PNG pictures are NOT iso style gfx...
Its a broken 3D gfx...

Why artist don't use this? Why want the use the flat one?
Because iso works with it! Because you can show more details! Because only
this
fools the eyes.

Now i include the pngs all people from you called "flat"...

     http://mids.student.utwente.nl/~michtoen/isodemo/demo3.png

Hello? What is flat here? You see it? Welcome to ISO style gfx.

Our flat little suckers mutate to real 3d like iso orcs...

Ok. WHY?

4. Hidden perspective lines

The *trick* are hidden in the grass... There are structures and
*perspective*
lines in it, which let your eye see the "iso perspective*.

I had drawn lines in this picture to show you where they are...

* i had drawn the lines *more* turned to the perspektive, than the real
lines
in the grass structures are, so you will see difference easily **

     http://mids.student.utwente.nl/~michtoen/isodemo/demo4.png

Thats all? thats real all?
Yes.

Thats the whole trick.

The point is - The background must look as ONE perpective object.
When this is not the case - things start looking strange.

A nice demo picture. All objects are ok here, but vertical line,
sitting in the middle breaks the eye perpective... not much, but
it look good as when you put your hand on it and shows at the left one part.

     http://mids.student.utwente.nl/~michtoen/isodemo/demo5.png

This "hidden" perspective lines works also, when you had nearly vertical
structures.

At this demo picture, all things are slighty turned or not 100% vertical...
result...
See for yourself.

     http://mids.student.utwente.nl/~michtoen/isodemo/demo6.png

Give the background a look. See you, how the hidden structures in the grass
give you the
3D perspektive look?

But in real, the non vertical structures gives you the iso look. This 90°
thing.

So without. LOOK AT THE BACKGROUND. There is the perspective, NOT in the
figure.

     http://mids.student.utwente.nl/~michtoen/isodemo/demo7.png

Here with ...

     http://mids.student.utwente.nl/~michtoen/isodemo/demo8.png

5. So whats the point?

a.) Our problem are the png iso gfx.
DELETE THEM.

b.) We need this kind of background structures.

c.) We don't need 90° tiles like in AoE or Diablo.
The structures can also in rectangle tile included.
Look at demo7.png... its a rectangle. You can cut this in 32x32 tiles.
What you need is a collection of parts where the hidden lines go on.

d.) Its only a task of map making

6.) Are there more tricks

Some. Most is to had "in the whole picture" the hidden lines.
Because the lines are 90° its easy to draw when tiles are 90° too -
but Diablo 2 for example use big rendered parts. Inside there are not 90°
tiles... Its just more native to do it, but we don't must.

7.) How we can do it

In fact for us is easier to draw rectangles... Simply draw the lines in
bigger pictures
and cut them out.

** Then use for maps bigger structures **
Don't include like we had done in old maps vertical lines of same tiles...
This destroys the iso perspective.

Look at the grass structures of the demo pictures, that gives you
imagination
how this bigger structures works.

Its easy! You don't need much tiles. Plus some masks we can easily include
because we
have multi tile maps...

8.) Use background / object layers.

We had some gfx- trees for example who had included backgrounds. This must
removed also,
because you start getting trouble with the background structures.

But thats always a sign of good map editors to have logical layers.
Its something we had included in CF long time - Simply we don't use it in
our tile set.

This must be changed.

9.) For fun: true high levels.

If you ever think how the fancy high levels in AoE or other games works:
here.

The trick is, when you got a tile between 2 high levels - make this tile
*longer* or shorter*

Means, when all tiles 32x32. Make in a high levels first step 32x32, next
step (thats goind down)
28x32 and the bottom tile (where you see much room) 36x32...
This goes with masks.

Now, when a  object move in this, you had a speed x. 32/x are the pixels you
move every turn.

For the 28x32 tile is it 28/x ... means you can move faster (or slower when
calc it different).

Because you now have also a real *on the map existing* pixel difference, you
see in AoE the figures
really going high or down in the map... Because the tile SIZE is
different...

But thats only for fun, we want do this in CF before version 4.0 or so :)

     http://mids.student.utwente.nl/~michtoen/isodemo/levels

10.) Whats now?

Ok, lets talk about. I hope i had cleared the things for you.
Our problem is the background and the maps, meaning the use of background
gfx in the maps.

Also, when we dont include rectangle houses/dungeons , we got it.

Its simple to add a 90° dungeons, with 90° walls... in fact, we can do it
with the set we have.

Michael