Changing and making Body Data

Often, people use existing sprite pictures in order to create new norn breeds. Now and then one would like to "extend" the sprites to attach additional body parts, such as wings etc. That leads to the problem of changing the body data, since the body parts in the game don't seem to fit to each other any more. But let's start with some explanation first...

Norns in the game are "made" out of single pictures, for head, body, arms, legs and tail. Just like a marionette. The game needs data how to "puzzle" them together. Of course, you don't want a foot attached to the head! Therefore you need the body data. They "tell" the game engine how to make the norn out of the picture pieces.

By means of the body data, each sprite picture gets a set of points defined, where other points in pictures of other body parts get attached. Imagine a piece of cardboard attached to another piece and a needle is put through that point. Those pieces are attached to each other, but they can be moved around that fixing point independently. The data consist of two values: the X and Y coordinates in amounts of pixels relative to each picture. If you enlarge such a picture, of course, the "fixing point" also moves in the picture relative to it's coordinates and you need to change the value of the X and Y coordinates in the body data file.

As an example, I'll explain the changes I had to make, when I attached wings at the body of the Winged Pixies in the life stage "child".

If you open the sprite file b01j.s16 (body sprites for "child" of the Pixies) in the Spritebuilder, it looks like this. There are 10 pictures, numbered from 0 to 9 (numbers are in brackets).

This is the new sprite file with the "winged" body sprites. It's obvious to see that the pictures are far more larger than the original sprite pictures seen above. You can see how big the pictures are, the size is shown beside each picture in numbers of pixels, e.g. 50 x 64 right below the number in brackets which we learned is the number of the picture in the file.

Now let's have a closer look at one of the pictures. I take number 8. This is the body showing from the front.

That's how the original body front looks when you open it in the program "Paint". Enlarge it to 600% and you can see each pixel. Can you see the pink pixel in the upper part of the picture? I let a red arrow point to it. Go there with your cursor. Now read the values in the lower right corner...wait... it's too small on this picture, I enlarge it:

The number in front of the comma (in this case a "13") is the value for the x-axis, behind the comma (here a "2") for the y-axis. Understood? The pixel is very easy to find. Just count 13 pixels to the right and 2 pixels from above and you got the position where the pink pixel is located in the picture. (Actually, if you really count the pixels, there are 14 pixels to the right and 3 downwards, but the first pixel line is numbered with a "0", so start counting with 0 not with 1!) Oh, and now you already know that the 0-point for this coordination system of pixels is in the left upper corner.

Now let's have a look at the original body data file for this sprite file:

I marked the coordinates we found above in red. See that it's in line 9? Well, my text program starts counting the rows with 1, but the pictures in the sprite file start with a number 0. Do don't get confused! The ninth row corresponds therefore to the eighth picture in the sprite file!

And what do the other numbers mean in the same line? Well, the body needs six attachment points in total. One for the head, two for the arms, two for the legs and one for the tail. Each attachment point needs a x- and a y-axis coordinate, which means, in total there must be 12 numbers. And they are just written one after the other in one line (head, left leg, left arm, right leg, right arm, tail). Each of these lines has the corresponding picture in the sprite file.

Now this is the new sprite picture with the wings attached to the body. Now point the cursor again to that pink pixel above the body. Now read the value. Of course, it got larger, since the picture got larger as well.

This value has to be put in the same position in the body data:

Now you have the first attachment point in the picture. Now you're able to calculate all the other attachment points of the body, since the attachment points relatively to the body picture didn't change. They're just lay on other coordinates. Add resp. subtract the difference between the new coordinate value minus original coordinate value. All you need is a little bit of patience and a calculator. Or use an excel sheet.

Usually, attachment points aren't painted in pink in the sprite files. So I sometimes marked them (of course, not permanently!) with another bright colour in the original picture, in order to be able to find them easier in the changed picture. For this it's easier also to have two windows of "Paint" openend, one with the original picture, one with the new version. Once an attachment point is marked in a completely other colour, it's much easier to find the same point in the new version picture. Then take the coordinate values via the cursor and the value shown in the lower right corner in Paint, just as we did before. And then calculate the other attachment points or look for them in the picture.

Available for C2 is also the Attachment Editor from Creaturelabs. It's pretty useful once you're know your way around. ;-) The method I've shown is a bit more time consuming, maybe, but can be applied also to breeds of all Creatures versions.