Making Sprites

Note: Activeworlds now supports .png files with transparency for both textures and pictures. This means it is no longer necessary to create separate image and mask files, however parts of the process are still applicable. This method will still work, though it means extra effort.

Before we get started, some terms:

Sprite- A sprite is an Activeworlds object that rotates so that it always faces you. This has the effect of making a flat picture look 3D to a degree.

Mask- A mask allows us to make objects on invisible backgrounds, so you can have, for example, a tree that looks like a tree, not a picture of a tree on a white background. In other words, you see just the object, not the stuff around it in the original picture.

To make a Sprite:

We will be making sprites by putting a texture on an existing sprite of the size we want. That is, instead of creating a sprite from scratch, we’ll be putting our picture and mask on an existing sprite object. This is a lot easier, and sufficient for our purposes.

The sprite process will consist of two parts: making the texture file and making the mask.

Step 1: find a picture

Saving images from the Internet:

1. Find an image you wish to save.
2. Right click on the image.
3. Left click on “Save Picture As”
4. Navigate to the folder where you want to save your image (for example: for students, this might be on a file server for your computer lab, for mentors, it could be your CTC user folder or the Desktop.
5. Name picture and click “Save” (picture should be either a “GIF” or a “JPEG”)
6. If your picture is a “GIF” you must save it again as a “JPEG” in Photoshop (any other format should also be converted to JPEG).
7. Important Note: Make sure you keep a record of the exact address where you found each picture. You may want to do this in Word or Excel. Simply copy and paste the address form the address bar. This is extremely important in terms of your bibliography and for reasons pertaining to copyright.

Find a picture off the internet. Try to find one where the object you want to turn into a sprite is very defined. It should be something that is distinguishable from its background- something you could trace. It should also be whole- not cut off in the picture. Half a frog wouldn’t make a very good sprite

Step 2: make the picture files

Overview: Once the picture is in Photoshop, you need to resize the picture. You will do this by right-clicking on the blue bar at the top of the picture. Your goal will be to create a final canvas size of 128 pixels by 128 pixels. It is very important that before you do anything else, you give the picture these dimensions.

Next, you will need to make a copy of this picture, which you can convert into a mask. Do this by right-clicking the blue bar at the top of the picture, and selecting Duplicate.

The resized picture is your texture file. It’s all set to go. The only thing left to make is the mask. This is the tricky part.

The mask is a file that, if you placed it over your picture, would be white everywhere you wanted to show up, and black everywhere else. For example, here is a picture of a parrot, and it’s corresponding mask. The mask makes it so all we see when we apply the parrot texture is the parrot- not any of the background stuff.

NAMING: The filename should be the texture name with an m at the end. For example, "parrotm" would be the filename for the parrot mask.

Below are step-by-step instructions for sprite making.

1. Open Adobe Photoshop.
2. Bring your jpeg picture into Photoshop by going to file – open
3. Then navigate to the folder where you saved your picture.
4. Double click on the picture or click on the picture and click “open.”
5. Right click on the blue bar at the top of your image and left click on “Image Size”
6. Make the Pixel Dimensions 128 x 128 (if this cuts out any portion of your picture you may go to 256 x 256, or 512x512). Please note: the lower the pixel dimensions, the better the sprite image will work in Active Worlds.
7. Click “OK”
8. Right click again on blue bar at the top of your image and left click on “Canvas Size”
9. Click on the drop down arrows at the right and change the “inches” to “pixels.”
10. Set both the width and height to 128 pixels if possible (or any combination as above, keeping in mind the lower the numbers the better)
11. Click “OK”
12. Save image
13. Right click on blue bar over image again and left click on “Duplicate”
14. Click “OK”
15. Click on “Image” in top toolbar
16. Click on “Mode”
17. Click on “Grayscale”
18. Click “OK” to discard color information.
19. Click on lasso tool
20. Use lasso to trace your image (keeping as close to the outer lines and details as possible)
21. When you have finished click on the paint brush (you may increase the size in the top toolbar)
22. Select the white color and paint your image white
23. Click on “Select” in the top toolbar and click on “Inverse”
24. Select the color black and paint your background black
25. Go to “Image” – “Adjustments” – “Brightness/Contrast” in top toolbar
26. Increase “Contrast” to 100 – click “OK”
27. Go to “File” – “Save As” and add an “m” to the name of your image.
28. Use the drop down arrow under “format,” scroll up, and select “BMP” (“.BMP, *.RLE, *DIB) (example: if your file was named lion, it should now read “lionm.bmp”)
29. Click “Save”
30. A “BMP Options” Box should appear. Make sure that “8 bit” is selected under “Depth” Click “OK”
31. Both the original resized color jpeg and the bitmap mask need to be put in the Object Path textures folder at Cornell (by a mentor) for this to be used.
32. The jpeg file goes in the textures folder as is, and the mask must be zipped.