Custom objects can be made in Paint. I do it all the time. Some tips:
- I only recommend Paint if the object is not animated, or if bits of it touch each side of the frame. This is because there is no variable size grid in Paint. If there is a very thick border or lots of one color surrounding the object on at least one side, you may find yourself having to count pixels to make sure everything is in the right place.
- Paint XP has a 10x zoom, but it's a secret. Click on the magnifying glass to show the zoom options, and then click on the very bottom of the list with all the zooms listed. If you get 8x zoom instead of 10x zoom, that means you didn't click low enough; keep trying.
- You can easily copy something by selecting it and holding the Ctrl key as you drag it.
- Black is transparent. Unless your CO has rounded edges
- Remember that because black is transparent in the game, anything that is black will not show up. If there is something you want to show up as black in your Custom Object, create a color that is close to black (double click on a color, go to custom, and put a small number like 5 in for red, green, and blue)
- Your image must be a PNG and saved in the Custom Objects folder in your world folder.
- If your Custom Object is not exactly 24x24 pixels in size, then you need to define Tile Width and Tile Height in World.ini. Also, if it's longer than one frame, I think you need to define Init AnimTo before it will animate.
If it is still not showing up in the game, please attach World.ini and one of your images to a post here so we can see what you're doing and tell you what you need to do to get it to work.
Again, making animated Custom Objects in Paint is relatively easy to mess up in part due to frame sizes. If you Here's the best way to do it, IMO:
Start by making an image filled with boxes. Each box should be the size of one frame of animation, and there should be enough boxes to fit the whole animation. Last but not least, make sure not to have any extra space around the boxes. For example, here's boxes for a 4-frame animated CO that is 26 pixels wide and 16 pixels tall.
(http://imgur.com/khEYU.png)
What you would then do is draw one frame of the animation into each of the boxes.
(http://imgur.com/tsIV6.png)
Then fill what's left over of the boxes with black.
(http://imgur.com/8PaAr.png)
For reference, here's what I added for it in World.ini:
[Custom Object 1]
Image=WobblyArms.png
Tile Width=26
Tile Height=16
Init AnimTo=4
Init AnimSpeed=80
And here's how it looks in the game:
(http://imgur.com/Hm2ma.gif)
Paint is a limited program, so I recommend you consider learning how to use other free image editing tools, such as GIMP (http://www.gimp.org/). Not only do such programs make it easy to do complicated tasks like blurring and recoloring, but many also let you use layers. Also, you get to use real transparency - not KS's confusing transparent black.
You write it from scratch in World.ini. You can put it anywhere in there as long as it's not right in the middle of an existing group.
Make your own group starting with "[Custom Object 1]" or whatever number you want (as long as it's >0 and <256) and define the variables there. The ones you should know about:Image= (the name of the image, like Bottle.PNG)
Init AnimTo= (the number of the last frame. Note that the first frame is frame 0.)
Tile Width= (width of a frame in pixels)
Tile Height= (height of a frame in pixels)
Init AnimSpeed= (Higher numbers for faster speeds.)
Init AnimRepeat= (0 for infinite looping. Any other number to loop that many times.)
If you're asking how to program COs to do special stuff: Haha, we wish.
Unfortunately, a CO is an animated graphic, and nothing more.