Multimedia Toolkit 2/Multimedia Toolkit 2.iso/imagine/tutorial/3d_font_tutorial.txt

Text File | 1991-10-20 | 10.0 KB | 172 lines

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              TUTORIAL for 3-D FONT construction in Imagine

                            by Carmen Rizzolo

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NOTICE: This tutorial assumes you are familiar with the provided Imagine
manuals, and understand them.  - KIDDING!!!

    Almost all of the 3-D work I do professionally deals with "Logo
Treatments" or 3-D titles.  Obviously, knowledge of how to make clean, sharp
3-D letters is helpful.  The following is a step-by-step tutorial of how
construct 3-D lettering.

STEP 1: Painting your text

    Start your Imagine project.  Let's say you named your project "3D-Text"
(Without the quotes).  Imagine then creates a drawer called "3D-Text.imp"
in the same directory that Imagine is located in unless otherwise specified.
After the "??.imp" drawer is created, go into a directory utility and look
inside your "??.imp" drawer.  You'll see a drawer named "objects" and your
rendering sub-project drawer if you've made one it yet.  Add another drawer
and call it "brushes".
    Boot up your 2-D paint program.  Select Hi-Res in 2 colours.  Pull up
your font requestor and choose a nice big font.  I like to use fonts that
are AT LEAST 75 points in size.  Scalable fonts are wonderful for this
purpose.  If you don't have access to large fonts, fetch the biggest font
you have and grab it as a brush.  Double the size of your brush and clean
up the jaggies (Figure 1).  A larger IFF image will mean less clean-up
time in Imagine, and a more accurate object.  I usually use an image twice
as big as the doubled image in Figure 1, but this is not manditory.  Move
the image of your text to the farthest upper-left of the screen as
possible.  Once converted to an object, the axis will be where the very
top-left pixel is of your image.  Save your image as a PICTURE, not a brush
for good measure.  Sometimes, Imagine doesn't like objects that "Convert
IFF/ILBM" makes from brushes.  I think the problem originates from the type
of hard-drive controller you may have.  It is good practice to save this
picture in your newly created "brushes" drawer, where you can also store
images for brush mapping/wrapping.  Exit your 2-D paint program.

STEP 2: Converting IFF to an outline object and cleaning up

    Back in Imagine, enter the Detail Editor and use the "Convert IFF/ILBM"
item under the "object" pulldown menu and select your text image.  Imagine
will then convert your Image to an object with an out-lined representation
of your image.  There are no faces on the object yet.  Only points and
edges.  It's now time to clean up the object.  You will have two main
objectives:

1. adjust curved edges and evenly distribute the points on curves
   (Figure 2).
2. level off straight edges and make sure that straight lines only have two
   points (Figure 2).

    To move points around, simply select "Drag Points" mode and drag the
points where you wish them to be.  Occasionally, a line that is supposed
to be straight will have an extra point or two in it, creating a crooked
line.  To correct this, enter "Add Lines" mode.  Click once on the point
at one end of the preferred straight line, and again at the other end of
the line.  Now use the "Pick Points" mode and select all the undesired
points between the line's two end-points and delete them.  In most cases,
curves will not look smooth enough because too few points were given to it.
To add a point to a line, go into "Pick Edges" mode and select a line that
needs another point by clicking on the points on each end of the line.
Then select the function "Fracture" to create another point in the middle
of the selected line.  Now you can go back to "Drag Points" mode and
re-distribute the points and efficiently smooth out the curve.  The closer
the font will be to the camera in your renderings, the more points your
curves should have assigned to it.  If your curve doesn't have enough
points in it, the curve will have unwanted dents or "corners" in it where
edges intersect (Figure 2).

STEP 3: To phong or not to phong

    Save your outlined object.
    Make a copy of your outlined object by selecting it, then select "Copy"
then "Paste" under the "object" pulldown menu.  Now there are two of your
outlined objects, although they take up the same space.  Most letters and
numbers have both straight and curved edges (Figure 3).  Some edges we will
assign "phong" shading to, while others we will not use phong.  Phong shading
helps to smooth out curves to make them appear to be true curves.  Phong
shading does not work well with sharp angles because it tries to curve out
all corners.Since an object cannot contain both phong and non-phonged
surfaces, we have two seperate objects.  Mentally determine which edges have
curves, and which are only straights and sharp corners.  Look at Figure 3.
Note that the main stem of the T is phonged.  Even though it is mainly a
straight edge, the bottom curves out into the foot or "serrif" of the T so
that edge should be phonged.  Select one of the two copies of the outlined
text.  Be sure you have NOT extruded anything yet.  Go into "Pick Points"
mode and delete all points that belong to a phonged edge.  See Figure 4.
Select the other of the two objects and delete all that belong to non-
phonged edges. Use the Amiga-N key comination yo cycle through your
objects to make certian that no objects share edges in the same place (Note:
it is acceptable for the two objects to share POINTS in the same space,
especially where a phonged edge meets a straight edge).  Go into the
attributes of the non-phonged outline object (Select it, then press F7) and
turn off the PHONG button.
    Make a copy of your "phonged" outline object.  Now look for sharp edges
that will not look good if the phong shading tries to round it out
(Figure 3).  Mentally note where you must seperate the objects at these
intersections.  Remember, both phonged objects points must share the same
space where the intersection will be broken.  For this reason, we are not
using the "SPLIT" feature, but duplicating and trimming the objects into what
we need.  Now use the Amiga-N key combination to cycle through all your
objects and make sure that neither of your phonged outline objects share
edges in the same place.
    Extrude all three objects (1. The non-phonged outline, the phonged
outline, and the other phonged outline used to eliminate sharp edges).
Use the default settings for now.  If you wish the objects to be thicker
or thinner, you can multi-select them all and size them later.  After
extruding, multi-select both of the phonged objects and use the JOIN
function (NOT, I repeat, NOT MERGE!).  Not GROUP (NOT JOIN OR MERGE) the
phonged and non-phonged objects and save them under a different name than
your original outlined object.  Delete all objects (from the screen, NOT
THE DISK!!)

STEP 4: Slice is your friend

    Load up your original outlined object.  If you have limited  memory
resources, you must enter the "Add Faces" mode and do so, filling all the
desired areas in the text with triangular faces.  If you're blessed with
3 or 10 MEGS, use SLICE.  If you're familiar with SLICE, skip to the next
paragraph.  If not, READ ON, PIONEER!  Extrude the outlined object using
default values.  ADD a plane object.  your plane does not have to be
riddled with small faces if your text is simple.  For something as simple as
the letters in "Hello" you can use the default values of 10x10 sections of
faces.  Be sure your plane is upright, just like your newly extruded text.
Position your plane so that it is surrounding the text in the front view,
and "cutting" through it in the top and right views.  Be sure the edges
of the plane in the front view isn't too close to any edges of your text.
You can be liberal in your (plane) scaling here.  I think SLICE doesn't like
it if the axis of your plane and your text are touching in any view, so
I usually move the plane up and to the left if the text axis happens to be
centered.  This might be my Imagination, but it doesn't hurt.  Multi-select
both the plane and your text.  Now select SLICE.  If nothing went wrong,
you should now have an additional axis on the screen with all scraps grouped
to it.  Select the axis, select Un-Group and delete the axis.  Now delete all
the unwanted trimmings from your slice.  This includes "holes" in O's and
lower-case e's, etc.  Not bad, eh?  Go into your trimmed object's attributes
and turn off phong.  Save your object (Don't write over your sides object!)

STEP 5: Almost done!

    Load the Sides object from the end of step 3.  Un-Group the phonged from
the phonged sides.  ADD an AXIS.  Move the axis to the center of your text
objects.  Select the AXIS, then select all of your text "parts" (or use
Select All in the menu) and GROUP.  If you plan on viewing the back of your
text, make a copy of the front object and move it to the back.  In order to
insure seamless grouping, zoom all the way in when positioning your back
object.  As long as you did not move (re-position) any objects in the
course of this tutorial, your front and sides shold already group seamlessly
for your renderings.  Be sure your back object is grouped with the rest of
the bunch.  Select your main AXIS in Pick Groups mode (<-IMPORTANT!) then save
your final object.  You now have an object that has professionally clean
sides, and the front of your text is grouped, not joined, so changing the
attributes will be a simple operation.

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    That's all there is to it!  I did not cover beveling techniques because
that's a whole different story!  Also there are several ways to bevel text,
most of which can make the 3-D font creation take twice as long to make!
    Thanks for excusing any spelling errors in this document.  For those lucky
folks with a DCTV or any other 24-bit device, this 3-D font technique will
really shine on their monitor.  Drop me some E-Mail if this file helped you
out at all.  Till next time!

                                         Carmen Rizzolo