Learn how to make 3D objects
from images, create neon signs and stop your
wagon wheels from slipping on slick virtual
surfaces in this exercise. A great project for
intermediate users looking for a few new tricks.
Many animators need to render
or animate objects represented only in
photographs or drawings. In this exercise, you
will learn how to create three-dimensional
objects based on two-dimensional images. This
exercise also demonstrates a technique which
lets you accurately animate the rolling of a
wheel. The rotation of a wheel is directly
determined by the distance the wheel rolls. The
expression assigned to the wheels of the cart in
this image ensures that the wheels will rotate
exactly the amount required to account for the
movement of the cart. This in turn ensures that
the wheels appear to roll over the ground rather
than just slip against it.
click here to download the
animation which shows the wagon rolling forward. You can also
download the Wagons Roll source file
required to complete this exercise, or the
finished Wagons Roll file, if you
All the files listed above are self-extracting .exe files, which
means that if you run them they will decompress to either .max files
or .avi files, which can then be viewed or loaded using 3D Studio
Creating Neon Text
In this animation, the sign features neon text created by lofting
a circle along a spline. You apply a selfilluminated material to the
sign that incorporates a Material channel. When you render this
animation using Video Post, you can make the text glow.
In the steps below, you learn how to create the path for the neon
text by creating a spline, using normal 3D Studio text as a guide.
As you create this loft path, you learn and use various techniques
that you will find useful whenever you need to draw 2D splines.
1. Hide all objects except the object called Maxtext.
2. Activate the Front viewport and press the W key to change the
viewport to full screen.
3. Select the Create tab.
4. Select the Shapes icon.
5. Select the Line icon.
6. Place your cursor in the middle of the lower-left 'foot' of
7. Click and drag up to the upper-left corner of the M.
8. Continue to draw lines through the center line of each letter,
creating a continuous path which represents the path of the neon
letters. You are aiming for the shape shown in the image below:
9. If you want to back up, you can press the BackSpace key to
delete the last point that you made. If you exit the Line command
before you complete the continuous path, delete the spline and start
How you place each point is important. If you click the mouse
button while the cursor is not moving, you create a straight line.
If you click the mouse button and move the cursor before you let go,
you create a curved line. How much you moved the mouse determines
how curved the line appears. If you right-click before placing the
second point, the Line-Drawing command is canceled. If you
right-click at any time after placing the second point, the
Line-Drawing command is finished.
Modifying the Line
It is easier to change the shape of the line than to create a
perfect line from scratch. Select the shape that you want to edit,
then select the Modify Spline button from the Modifier command
panel. This modifier gives you access to the vertices and segments
of a spline, which in turn lets you move vertices and segments to
refine the shape of your curve. You can also modify the spline as a
complete entity. The main uses of these levels are:
Vertex- You can select and move/delete an individual or group of
vertices. You can change the curve/shape of the line going into or
out of the vertex by right-clicking a selected vertex. You can also
weld selected vertices together.
Segment- You can select and change an individual or group of
segments. You can add a vertex to the segment to refine it, or you
can straighten a segment by selecting it, then right-clicking it and
changing the segment type to linear.
Spline- Lets you attach one spline to another. If you do this
with two splines, the face normals of one side of the object may be
flipped. To fix this problem, change back to the Vertex level,
select all of the vertices by drawing a selection window around the
splines, then choose the Weld button from the command panel.
Follow the steps outlined below to
refine the shape of your path:
1. Select the spline.
2. Select the Modify tab.
3. Select the Edit Spline button.
4. Select the vertex that you want to move.
5. Use the Select and Move icon to move the vertex.
6. Right-click the selected vertex to change the type.
7. Click and drag the green handles on either side of a curved
vertex point to change the curve going through the vertex.
8. To change the curve on one side of the vertex, hold the Shift
key down, then click and drag the green handle.
Lofting the Neon Sign
To create the neon sign object, loft a circle along the spline
you just created. Follow the instructions outlined below to complete
1. Unhide the 2D Spline called Circle01.
2. Select the path.
3. From the Create command panel, choose Loft Object from the
Geometry drop-down list.
4. Select the Get Shape button.
5. Choose Circle as the shape.
You create the neon material by following
the instructions outlined below:
1. Assign a red or yellow material to the lofted object. Create
the material with a Self-Illumination value of 100. Change the
Material Effects Channel number to 1. If you do not know how to
create a red or yellow self-illuminated material how to create
2. To see the effect, unhide all geometry and render the Camera
viewport using Video Post to glow the neon material with a Glow Size
value of around 15.
You have just created neon text. You can use this technique to
dress up virtual bars or roadside cafe's along the super-highway.
Creating Objects from Photographs
In the sections that follow, you load a bitmap image as a
background and display it in the Front viewport so that you can
trace over it. This technique is very useful when you need to
recreate a logo or an object in a photograph.
Note: You can also use this
technique to create plants and flat people in your animations. When
creating plants, you might want to rotate and copy the flat plant
objects so that they are at right angles to one another. This
creates 'almost' 3D plants.
Note: You can't zoom in or
out of the bitmap when it is displayed as a background in a
viewport. It fills the viewport, and you can only alter the display
of your 3D objects in front of the bitmap. The bitmap image used for
this exercise is called OLDWOOD.JPG, which you can find in your
Default Maps directory.
1. From the Views main menu, select Background Image.
2. Select the Files button from the Background Source panel.
3. Search for and select the OLDWOOD.JPG file. After you have
found the image, you can click the View button to take a look at the
image before you assign it.
4. Select OK to return to the Viewport Background dialog box.
5. Select the Display Background checkbox to activate the display
of the image in the viewport.
6. Select the Bitmap checkbox in the Aspect Ratio section so that
the image does not distort in the viewport.
Tracing the Image
Use the techniques described on the previous page to draw a
single, continuous line around the edge of the wood image. Follow
the grain of the wood and draw lines that inset at the ends of the
planks of wood in the image.
After you have drawn the line around the image, you will extrude
it, so make sure your spline is closed. You can close the spline in
one of two ways:
1. Double-click to automatically join the last vertex to the
first vertex, or
2. Place your cursor over the first point. When the cursor
changes into a cross, you can close the polygon by clicking.
Extruding a Polygon
Now that you have created the spline, extrude it to create a 3D
1. Select the Spline.
2. Select the Modify tab.
3. Click the Extrude button.
4. Enter 20 in the Amount field for the thickness of the
5. Select the UVW Modifier button and the Fit button at the
bottom of the command panel to shrink the mapping coordinates to the
size of the extruded shape.
Assigning a Bitmap to an Object
To create a material which will place the bitmap you just traced
right on the object you just created, follow the steps outlined
1. Select the extruded object.
2. Select the Material Editor icon.
3. Select the Diffuse button and select the OLDWOOD.JPG image for
4. Select the Assign Material to Selected icon.
5. Select the Show Map in Viewport icon. This shows the material
assigned to the object in the shaded
6. Adjust the position of the map using Offset and Tiling. This
lets you line up the bitmap precisely with
the extruded object.
7. Render the Front viewport to see the image on the object.
Note: You can always view
maps in viewports. The trick is to be at the Image Allocation level
in the Material Editor, as the Show Map in Viewport icon then
becomes active. When you click this icon, the image will be
displayed in shaded viewports.
Use this technique whenever you need to create objects based on
photographs or drawings.
Making Wheels Roll Correctly
The following example shows how to make a wheel roll along the
ground without the circumference of the wheel slipping. The wheel
follows a dummy object, and the rotation of the wheel is calculated
in proportion to the distance that the dummy object travels in the X
direction. This ensures that the wheel rotates exactly enough to
account for the movement of the dummy object. By linking a cart to
the dummy object, you ensure that moving the dummy object makes the
cart move and the wheel roll exactly as physics demands. You can use
the technique illustrated here whenever you have a wheel or cylinder
that you want to roll along
To create the expression, use two dummy objects, one to establish
the starting position of the wheel and the other to calculate the
distance moved from the original position. When you create the dummy
objects, do not change their names from Dummy01 and Dummy02, so that
you can follow the rest of the example. Dummy02 represents the
original position and Dummy01 represents the new position. Note: The
wheel object is a grouped object in the scene, and grouped objects
cannot contain an expression controller. A dummy object linked as a
parent to the wheel has the name Wheel. This is the object used for
the rotation controller in the example.
Changing the Controller of an Object
The first stage in assigning this expression controller to an
object is to change the wheel object's default Rotation controller
to Euler controller.
1. Create a dummy object near to the front wheel of the wagon.
The exact position is not important. Make sure that the dummy object
has the name Dummy01.
2. From the Edit main menu, choose the Clone option to create a
clone of the selected object. Make sure that the clone copy has the
3. Click the Select and Link icon from the main toolbar and link
the wheel object as a child of the Dummy01 object. You may have to
press the H key to select the Dummy01 object.
4. Select the wheel object so that you can change its controller.
5. Select the Motion tab to open its command panel.
6. Select the Assign Controller rollout to open the section.
7. Select Rotation from the Hierarchy list.
8. Click the green Assign Controller icon above the Hierarchy
9. Choose Euler XYZ from the list and OK the dialog window.
10. Go back to the Hierarchy list and highlight Y Rotation.
Assigning a Rotation Expression
Having changed the Rotation controller for the wheel to Euler
rotation, the second stage is to add an expression controller to the
Euler rotation for one of the axes. When you use Euler rotation with
a calculated expression, the axes used are based on the World axes.
1. Highlight Y Rotation in the Hierarchy panel.
2. Click the Assign Controller icon just above the Hierarchy
3. Choose Float Expression and OK the dialog window.
4. Highlight Y Rotation in the Hierarchy list; it should now say
Float Expression to the right.
5. Right-click Y Rotation and choose Properties from the list.
This opens the expression controller.
Generally, you use the expression controllers to calculate
positions of objects. In this example, you enter a specific
calculation or expression for the Y rotation of the wheel object.
You can make one object in your scene refer to the position of
another object in your scene by creating a variable that stores the
position of the first object. You create and use this variable in
the expression controller for the second object. In this exercise,
you use this technique twice, once to capture the position of the
original dummy object and again to capture the position of the dummy
object attached to the wheel. You also enter the formula for the
angle of rotation of the wheel in relation to how far it moves from
the original position.
1. Enter the letters dold in the Name panel of the Create
2. Click the Vector checkbox.
3. Select the Create radio button.
4. Select the Assign to Controller radio button.
5. Open the Objects hierarchy until you see the position track
for the Dummy02 object.
6. Highlight the position item for the Dummy02 object and OK the
7. Repeat all of the above steps with a variable name of dnew and
assign the Dummy01 object to that variable.
Entering an Expression
If you successfully created the two variables in the previous
steps, you can now enter the calculation for the angle of the wheel.
The expression or calculation that you enter now is evaluated and
applied to rotate the wheel along the Y axis. The number in the
expression area represents the current angle of the wheel, which
should be zero. Enter the expression exactly as it appears in the
If you move Dummy01, the wheel will roll exactly the amount
required to account for the movement of that dummy object.
To finish the model:
1. Repeat the steps outlined above to create a Dummy03, which
controls the rotation of the second wheel.
2. Link all the components of the cart, including the wheels, to
the Dummy01 object. Moving the Dummy01 object will then move the
cart and roll the wheels.
Note: Moving the Dummy02
object will also roll the wheels (although not move them), because
moving the point from which roll distances are measured.
Did you like this lesson or
perhaps you would like to comment on it or need
help. Go to our
discussion area and start a new discussion
or start a new article, or ask for help and a
MaxNet Engineer will respond.