Here's a couple of useful things that can be done with srbs. By editing
the .3do file the srb can be mirrored or flipped, and can also be
shaded or colourized. Obviously this can be done by using different
.srbs but the advantage of editing the 3do instead is that the same
.srb (bitmap) can be used for different things, which is more
economical - the 3do is a couple of hundred bytes at the most, compared
to for example a 256x256 .srb which is 43.1Kb (4-bit) or 171Kb
(16-bit). Of course you'll still need different 3dos, even though they
all use the same .srb.
This can be done using GPL Editor to change the unk value of the srb.
All you need to do is open the 3do in GPL editor (e.g tree.3do, not
tree.srb), expand the PRIM tree until you find the srb, double click
and enter one of the following values in the unk box:
65536 - this is the default value; the srb will be orientated 'normally'
0 - this will mirror the srb left-right
65538 - this will flip the srb top-bottom
2 - this will mirror and flip the srb
This needs to be done with a hex editor but it's very easy to do as only a few numbers needs to be changed:
1. open 3do in hex editor
2. find the srb type - this will be 40 bytes from the end of the file
(60 bytes from end of file if 3do has collision) and will be 03 00 00
00. Change this to 03 0a 00 00
SRB 3do in hex editor:
SRB with collision in hex editor:
3. After 03 00 00 00 there's 4 bytes of 00 and then four bytes for the
colours (will probably be ff ff ff ff to start with) - 1st byte is
blue, 2nd green, 3rd red, 4th alpha (transparency). This can be edited
here or (if you prefer decimal) can be changed in GPL Editor.