Pelican
Briefs
Manual #001: Making
Sprites
What is a 'sprite'?
A
sprite is a picture used in 3d environments that appears
as if it is floating. No matter which way you view a sprite,
the sprite will appear to rotate towards you, always showing
just one side. That is the beauty of a sprite. Pictures and
photos can be displayed to seem as if they are truly 3d objects
rather then merely 2d photos.
A
sprite is made up of 3 parts. An image, a mask, and a flat
object to display your image on.
The sprite image
An image
can be any picture, drawing or photo that has been saved
in the *.jpg format. One example of this can be seen below.
 buddha.jpg
(Do not zip!)
The sprite mask
A sprite
mask is similar to the sprite image except all of the area
that you don't want to be seen, should be colored black and
all of the area you DO want to see must be colored white.
An example of this can be seen below.
 buddham.bmp
(Remember to zip!)
The
sprite mask must be saved on the *.bmp format and zipped.
Usually, the standard has been to name your sprite mask the
same as your sprite image with the addition of the letter
'm' placed at the end. It is then placed in the folder that
contains all of your textures.
The rwx sprite model
The script
below (figure 1.) is an example of a sprite model. If you
were to copy it into notepad and then save it as filename.rwx,
it would be a valid and recognizable file for active worlds.
It is merely a simple picture wall 3d object.
It
may look daunting but, amongst the "Vertex" and "UV" commands
are 2 lines of info that we will use. Just 2, that's all.
The first has been highlighted in blue "AxisAlignment
XOrientY". This merely tells the object to always turn
and face the viewer. If you are making this sprite for hanging
on the wall, you could omit this line to keep your sprite
stationary.
the
sixth line from the bottom is the line that is most important
to us. "Texture buddha Mask buddham". This tells
the picturewall what to display. This one line is actually
2 commands wrapped into one. The first half is "Texture
buddha". This tells the picture wall to use the texture
(the image file) called "buddha" (and by default
looks for buddha.jpg).
The
second half of the command line is "Mask buddham".
This tells the picturewall to mask out the parts you don’t
want to see using the file "buddham" (and by default
looks for the zipped *.bmp of that name)
A
special note: All textures and masks are always in lowercase
lettering)
You
can exchange the file names buddha and buddham in the following
script for any other textures and masks you may have. Then,
save the file as a uniquely named ".rwx" file,
zip it and put it in the folder that contains all of your
object models. For example; name it "spritebuddha.rwx"….zip
it to "spritebuddha.zip" and upload it to the ftp
address that holds your objects. In Activeworlds, they are
usually all in a folder named "models"
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