a Pottery Vase
Easy - Beginners tutorial
This tutorial starts with creating a simple
revolve, then texturing the result into
a realistic pot. We make use of the "Scope"
handler to show how to clip an image onto
a surface that is already textured. All
project files and textures can be found
The Finished Pot
PART 1 - Modelling the pot
Start with a new project and select the
front view, turn off perspective and reset
Under the main toolbar, select Polygonal
curve by clicking the down arrow next to
curve, then polygonal curve. Leave all the
options at their default settings - we want
to draw an axis vertically that we can sweep
our pot around. Start the curve at the lower
middle of the view window; click once, then
make another mouse click straight up the
view and towards the top so the line is
roughly vertical. (Holding the SHIFT key
will keep your line vertical) If you keep
clicking at this point the curve can be
made more complicated - but all we need
is an axis so we will accept the curve at
this point by pressing the ACCEPT button
in the toolbar (you can also right click
and accept). This finishes the creation
of the curve.
To simplify matters - it is always a good
idea to name your objects. Under the select
window, we can see that we have created
a nurbs curve. By slowly double clicking
the nurbs icon we can rename the object.
Call it "Axis".
We now want to create the "Profile"
of the pot. Think of this as a section through
half of the pot that is "swept"
around our axis. Firstly though, we must
select out axis - make sure it is highlighted
before continuing. Under our main creation
tab again, select "Cubic curve"
this time. (Polygonal curves have sharp
edges - quadric and cubic curves are very
We are going to use the axis curve we created
as a point to rotate about when we make
our profile. To do this, we need to select
"Rotate" under our toolbar - click
the Pen option to see the different methods
- select Rotate.
Starting at right hand side of our axis,
click points from the base upwards to create
a profile curve similar to the one shown.
Each red point represents a mouse click.
To get sharp edges in a nurbs curve, we
need to put the points closer together.
Hence the top has three closely grouped
points. Note too that the curve draws both
the outside, then goes inside the pot as
The shape of your pot profile
Do not worry too much about how accurately
you place the points - you can edit them
later. Notice too how you can see the creation
of the revolve. When you have finished creating
all the points, click the ACCEPT button
again to finish creating the profile.
Rename our nurbs curve to "Profile".
Notice now that our level structure has
changed and we now have a mesh in the view.
We created the mesh by rotating our profile
curve about the axis. The two curves are
now put "under" the mesh. Press
the "+" icon next to the mesh
to see the curves below. By editing these
curves now will change the shape of our
resultant mesh. Note that a mesh is a 3D
surface - so when we render the image this
is what we will see. Generally, curves by
themselves are not rendered.
Rename the mesh to "Pot". Lets
tweak the profile curve a bit. Select the
profile curve, under the context sensitive
toolbar a series of options are shown that
we can do to this particular curve. Click
the EDIT button and we will move some points
around to create the shape we want.
If you click on any single point, the cursor
changes to a cross. This means that you
can now click on the point and move it around.
Do this for each point until it looks roughly
like the above image and has an even space
between the inside and outside. You can
now pan around the view and examine the
pot you have created.
To get a better feel for the shape - turn
on Open GL view to see the mesh better.
You can also raytrace the view by pressing
This is a good point to save your work.
Under the File pull down menu, select "Save
As". Select the appropriate directory
by clicking the "..." button next
to the name field and Save the file as Pot_Part1
Texturing a model is about applying materials
to an object to achieve a given "look
and feel". These materials can be as
simple as colors, or as complex as applying
bumps, reflectivity, color and shine.
We can very simply drag and drop the standard
"glass" material onto our pot
to create a glass pot. Likewise, we can
make it gold, plastic or chrome by using
many of the standard materials.
But we want the pot to use an image. This
image could be a drawing, a color or a photograph.
We will map this image onto our pot using
the "Cylindrical mapping" method.
We have many methods to apply the image
to a model - parallel being the most obvious
- it projects the image onto the model in
the size and aspect you set when applying
the material. Cylindrical mapping works
on the same principal - but it wraps the
image around the cylinder walls - much like
the word COKE is written around a can. We
can wrap 1 image right around the object,
or we can make it "Tile" around.
If I wanted COKE to appear twice, I would
make it tile 2 times around.
In this example we are going to map a simple
strip of color around our pot to make it
look real. To do this we need to make this
"Strip" tile about the pot 10
times. Here's how we do it:
Load Pot_Part1 tutorial if its not already
active. Select the TOP view. Drag the Pot
object mesh from the select window and into
the view. This maximizes the object in the
view. (you can do this for any object including
We should now have a wireframe view of
the object like this.
Lets go to the Materials tab: In the select
window, select the Materials tab. Lets purge
any unnecessary materials for this project
- under the pull down menus, select Materials/Purge
material Library. This deletes any UNUSED
materials. If a material is being used,
it is kept. This should delete all the materials
as we have not assigned any yet.
By Right Clicking in the blank area inside
the material window, should bring up our
pop up menu. Select New/VSL material. This
creates a new blank material for us to edit.
Select the new material and rename it (by
slowly double clicking) to "Pot".
Now quickly double click the material. This
should bring up a new window called "Property
Window Sync". This shows us all the
selected objects properties. In this case,
it shows us the properties for our material
"Pot" which happens to be empty.
Lets fix this by using one of the pull down
wizards. Select "Texture Map"
from the wizard pulldown, Add this by pressing
the ADD button next to the wizard. This
inserts a file requester. Lets grab our
texture map image by clicking the "..."
button. (Next to the SHOW button) Navigate
to our Texture directory, and select "D_potside1.jpg"
Lets map this material to our pot - in
our material window, right click on our
"Pot" material and select Map/Cylinder.
This activates our tool to cylindrically
map our texture to our model. It automatically
assigns our material to whatever object
is selected in the select window. Which
should be our Pot Mesh as it is the only
To create our cylindrical mapping, first
click at the center of the mesh, then just
outside of the mesh. The result cylinder
should just encompass our pot at its widest
point. Rotate the view and see the result.
Click the "Side" view. It should
look similar to this image.
Note that the cylinder mapping is shown
dotted. It is also smaller than our pot.
We need the cylinder mapping to be just
a bit taller than our pot and just a bit
wider. It should be the correct width as
we can see in our TOP view that it is just
larger. Lets size the mapping to fit the
Go to the select window and examine what
has happened to our structure. Our mesh
has been dropped to a new level. Click the
"+" icon next to the level to
maximize its contents.
Note how the mapping is "level"
vertically with the mesh. This mapping is
now applied to anything inside this level
- but nothing outside of it. Select the
"Cylinder Mapping(Pot)". This
selects just the mapping object. Lets use
the handles of the object to position it
Put the mouse cursor over the blue line
of the object handle - the cursor should
change to a "Move" icon. Click
the mouse on the blue line and move the
object to just below our pot. This puts
our object handle out of view. If needed,
Pan the view so you can see the blue dot
at the end of the object handles.
Now put the cursor on this blue dot at
the bottom of our object handle - it should
change to a pencil icon - this means we
can scale the object about this axis. Click
and drag down to scale our mapping object
larger vertically. Keep modifying the object
until the mapping is just larger than the
pot. Note how the scaling or rotating of
an object occurs about the handle, hence
it scaled upward. If it was positioned in
the center of the object, it would be scaled
in both up and down directions.
Our mapping should look like this. Render
the view to see the result. As you can see
- we have applied our strip of color around
the pot but it looks awfully dark ! Lets
add some lights:
Go to "Lightsources" under the
main toolbar add some "Point"
lightsources: Select Point - and click on
the view for the lights center point, then
another click to define how far the light
should go. Add 2 or 3 lights around the
pot. Render the view to see your progress
and move the lights if needed. (Check your
top and side views for light positions -
move the lights by moving mouse over them
Above is the image that we have stretched
around the pot. (We have applied it vertically)
It is very narrow and this results in a
very "blocky" looking render of
the pot. What we can do is tile this image
around the pot a number of times. We change
this by editing the "Scale" parameter
of our mapping object;
Select the Cylinder mapping object, and
click the "Spec" tab in our "Property
Window Sync". (Remember we brought
this window up by quickly double clicking
any object). In the Scale field are three
numbers. "1 1 1". This means that
the mapping is mapped once in each three
directions (X Y Z). If we want our strip
to be repeated 10 times around, we actually
need to make it 1/10th of the times in the
X axis. Which means we need to Punch in
"0.1 1 1" There needs to be a
space between each value as each value represents
the X Y Z value. Try rendering the pot now
and see what happens.
Our pot has only a strip of the image applied
now ! This is not what we want - it should
be TILING around the object. We set this
parameter in the material itself. Go back
to our material tab and select out Pot material.
In our Property window, there is a checkbox
for "TILE X". Turn this ON and
render again. Much better ! We have now
tiled the image around our pot 10 times.
Just for the sake of making our scene a
little more interesting, lets add a ground
plane. In this case, lets put a disk underneath
the pot so we can see some shadows. Under
our Creation tab, select "Analytical
Disk" under the circle icon. In a Top
view, click the center point first (Center
of the pot) then another point further out,
well away from the pot. In a side view,
move the disk to just below the pot.
Save your work as Pot_Part2.
We have created a very basic pot with a
simple cylindrical texture applied. We will
continue fine tuning our material here and
also map on a "leaf" to the pot
that shows some of the power of VSL.
Load "Pot_Part2". This scene
has some lights and a ground applied to
show off our pot better.
Lets continue to tweak our material and
give the pot a few more realistic attributes.
Go to Materials tab in the select window
and select our "Pot" material.
Double click the material if the Property
window is not already up.
Lets use another wizard and add some "Ping"
to our pot, using the "Specular Color"
wizard - Add it too.
Try rendering the view to see the difference.
It renders as if it is made from gold. We
want a more subtle appearance - so change
the specular values to read:
Sharpness = 3.00
Brightness = 0.80
We could go on to add bump and a bit of
reflection if we wanted - but lets get started
on a new material to map a "leaf"
onto the pot.
Create a new material - right click in
select material window and select New/VSL
Rename the material "Leaf". (We
can do this by changing the name in the
Property window too)
We have two "modes" when creating
materials - Basic and Advanced. We are currently
looking at the Basic mode in our property
window. If we tick the "Advanced"
button at the top left we can see exactly
whats going on in this material. Lets do
Use another Wizard and create a "Texture
Map". This creates a new surface property
that is assigned to a texture. This texture
is, by default, assigned to the color channel
of an object. But we want it to be assigned
to the "Scope" attribute in this
case. The scope channel controls how much
of a material is shown and how much is not.
This is a powerful function that allows
us to put any image onto an already mapped
object (or unmapped) and clip out any undesirable
background so we have only the desired portion
shown on the image.
This has applications in assigning text
over a material and removing the background
so we only see the text. Assigning a complex
window bitmap over a brick mapped wall,
mapping a logo to a product etc.
We "Cut" our image out to do
this - generally with an alpha channel (Extra
information in an image that stores "transparency"
data - typically Targa files are saved with
an Alpha channel) We could also use a specific
color value to do the same effect - but
we have a Targa file with an alpha channel
Select our new texture map icon that has
been placed in the properties window (red
paintbrush icon) At the bottom of our properties
window we see a file requester window similar
to the basic version we used previously.
Select the texture "D_potleaf+A2.tga"
by pressing the "..." button.
If we were to map this texture onto our
pot now, it would overwrite the material
we created previously, so we need to setup
our "Scope" value so only where
the leaf texture is shall me mapped onto
our pot. Right click on the color=texture
icon and select Copy, then Paste. This creates
a duplicate of the texture we just assigned.
Select the first texture map. Right click
and under "Output >" select
"surface : scope." This changes
the output from the texture map to go to
the scope instead of the color. But by default
this is using the Red color channel to do
this. We need to go to the "Bindings"
tab and make the Alpha the channel to use:
Under the channel bindings we can see that
currently, the scope is assigned to color:R.
We need to change this. Check the "Edit
Bindings" button at the bottom. This
opens up more details as shown above. Select
the Color:R -> Scope under channel bindings.
Then Click the "Remove" button.
Now select "Alpha" under the Image
channels, and Scope in the Material channels.
The Add button becomes active. Add. This
now assigns the scope channel to the alpha
from the image.
And that is the basic structure of our
scope material. Lets assign this to our
pot and see what all this complicated VSL
does. Go back to the select window. Click
the FRONT view and make our pot full screen
(drag the mesh to the screen) Make sure
that the pot LEVEL itself is selected and
not the mesh as the material will but put
inside this level. Go to the material tab
again and select our "Leaf" material.
Right click on the material and select
Map/Parallel. Draw a rectangle roughly square
- starting click at the top left and 2nd
click bottom right. The map object is now
inserted under our level as shown above.
We can select the mapping object and scale/reposition
it as necessary.
Rendering the view should yield a result
similar to this:
Make a few test renders around the object.
Notice that we can move the leaf map around
the object and it covers whatever is under
it. But there is one small problem. The
leaf appears on both sides of the pot !
It is by default, mapped straight through
and will continue going on forever. If we
set the tile X + Y buttons on, it would
repeat over the object as well. In this
case, we only want 1 copy of the leaf, so
we will set some attributes under the mapping
Select parallelmapping(leaf). Under the
"Spec" tab in the properties window
are three toggles - select them all ON -
This limits the extent of our leaf material
to within the boundaries of our mapping
object. This is a very handy feature ! Modify
our parallel mapping object so it sits within
1 side of our pot and looks similar to this:
Finally, lets add a bump map to our material
to give it a realistic "raised brushstroke"
Select the leaf material. Using a wizard,
add a bump map. In the name field, select
the "B_potleaf+A2.jpg". Under
the Bump Height field, enter "-1".
Render your pot. Notice that all these
materials have very subtle effects. To see
what any of the parameters do - increase
the values. (eg. change the bump height
To finish off our scene - lets change some
of the values of the "Ground"
object without assigning a material to it.
Go to the select window and select the Ground
object. Under the "Col" tab of
the properties window are various surface
properties that we can change without the
need to assign a material to. (A material
would over right these settings)
Right click on the white square. Only one
options appears: "Expand". Click
this. This brings up our color wheel. Select
any color you like. Next to Attribute, Select
the "Reflection" attribute. This
uses a greyscale value to say how "Reflective"
an object is. Black is none, white is mirror.
Select a dark grey.
Your final scene should look like this.