Create a Snail - Blender 2.5 - page 296

The first parameter is warp . The job of this parameter is to use the informaion provided by
a texture as a "deformaion" to be applied onto the next texture on the stack. The actual
technicaliies behind it are a bit complicated and we're not going to discuss them, but
the idea is that the white areas of the warping texture will cause the most deformaion
(proporional to the value of the warp parameter), while the black areas won't provide
deformaion.
The second parameter is stencil . This parameter allows a texture to be used as a mask to
ilter which areas of the surface will be afected by the informaion provided by the next
texture on the stack; the white areas of the stencil texture will allow full influence of the
next texture, while the black areas will ilter it out enirely (thus muing the efect).
Scene Setup
The only remaining tasks that we have to do now are adding a plane for our snail, shaping
it according to the surface on which it will be composited on the real footage, and adjusing
the camera properly.
Engage Thrusters
We'll start by adding a curve to deform the body of the snail.
1. Let's switch to Front View ( View → Front ); make sure the 3D Cursor is located at
the origin of the 3D World ( View panel , in the Properties Sidebar ) and the view is
in Orthographic mode ( View → View Persp/Ortho or press Numpad 5 ).
2. Go to Add → Curve → Bezier to create the curve; with the curve selected, let's
switch to Edit Mode ( Tab key), switch to Right View ( View → Right or press
Numpad 3 ), set the view to wireframe ( Z key), select all the control points ( A key,
once or twice), and rotate them 90º ( R key, then type 90 ). Then switch back to
Front View ( View → Front or press Numpad 1 ).
3. To shape the curve according to our needs, let's select the leftmost control point
and move it -0.42 units along the X axis ( G key, X key, then type -0.42 ). Now select
the rightmost control point, move it -0.31 units along the X axis and 0.29 units along
the Z axis ( G key, type -0.31 , press Tab twice, then type 0.29 ).
4. Now let's extrude the rightmost control point and move the extrusion 1.64 units
along the X axis and -0.15 units along the Z axis ( G key, type 1.64 , press Tab twice,
then type -0.15 ); coninue by scaling down the handlers by a factor of 0.565
( S key, then type 0.565 ) and then rotate it by 5º ( R key, then type 5 ).
5. Finally, let's select the left handler of the middle control point and move it -0.078
units along the X axis and 0.052 units along the Z axis ( G key, type -0.078 , press
Tab twice, then type 0.052 ). This will get us the needed curve shape.