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From: groo@chsdip (Bill Squier)
Newsgroups: comp.sys.amiga
Subject: Re: Imagine raves - glass
Summary: Swiss cheese manual syndrome.
Keywords: Lots 'o holes.
Message-ID: <663190775-comp.sys.amiga@chsdip.UUCP>
Date: 7 Jan 91 09:41:14 GMT
References: <1329@compel.UUCP>
Lines: 73

In message <1329@compel.UUCP> her@compel.UUCP (Helge Egelund Rasmussen), writes:

>I've got some problems with brush mappings on simple objects.
>I tried to map a iff picture on a flat object (to create a painting), however
>the result is awful: Some of the faces of the object looks ok, but about
>half of the faces look weird.
>
>Brush mapping to non flat objects (ie. the flag from the tutorial manual) 
>works ok.

I had similar problems wrapping brushes on to flat planes until I
discovered something that the manual isn't too clear on.  Try the
following example yourself to illustrate the (serious) caveats of brush
mapping (example assumes default function key mapping):


In the detail editor:

Select Add/Primative/Plane, and except the default plane configuration.

Select it with [F1], and edit its attributes with [F7].

Select [] Brush 1, and an appropriate IFF from the requester.

When the Axis editing requester appears, select "Edit Axis".
A yellow square appears in the "Front View", and a line in the other two
views.

Press [M] to move the axis, and drag it (in the Front View) so the center
point is just outside of the lower left hand corner.  The "Front" display
will now look something like:

                    z
		---------
		|   :   |
		|   :   |
		|   .===|x
	      --|--     |
	      | | |     |
	      | .==-----|
	      |   |
	      -----

Where the smaller square is the yellow brush axis.  Note also that in
the top view, the two X axes are directly on top of each other (you may
have to be zoomed in before you begin to see this).  Here lies the first
problem.  Apparently, in order for Imagine to wrap the brush correctly
on to a surface, the brush axis must be offset slightly to one side or the
other.  Before we do that, SCALE the brush with the "S" command so that
the top right quadrent (the positive axes) encompass the entire plane. 
Now go to the top window and MOVE the yellow x-axis to at least 1 pixel
below the orange axis.  You'll note that it also moves one pixel in
front of the orange axis in the right view.  It is important that you
remember which face is the "front" of your plane.  In my test renderings
you see a blotchy-patchy IFF from the other side.  You will see this
same problem on both sides if you let the X axes sit on top of each other.

With all of that completed, press the space bar to return to the
requester, and select [OKAY] to return to the Attributes requester.  To
get the best image, turn "Dithering" way down (I usually set it to
zero), and select [OKAY].  Save your object, and move to the stage editor.

At this point, the only thing you have to remember is which was the
"front" of your object, and make sure the camera is pointing at it.

For other objects, just remember that the positive portion of the brush
axes is the part that contains the image.  It is this top right quadrant
(from the Front view) that must be enlarged and centered on the object.


-----
Bill Squier (groo)	Amiga :  uunet!tronsbox!dsoft!chsdip!groo (best)
`Only Amiga!'	        VAX   :  uunet!vaxb.stevens-tech.edu!u93_wsquier