Manipulators level.
An extra-level is about to be itroduced: Manipulators. An according button
is situated on the left of vertices level button and
+1 is a hotkey. On this level you can
modify a so-called "controlling points" or "manipulators". To switch to manipulators
level, an according object should be highlighted and then you can go down to this
level. An example will follow.
Switch to objects level and select Create\Light\Spot tool in commands bar.
Now press left mouse button and drag mouse in top view, then release button and
a light will be created:
Highlight this spotlight and switch it to manipulators level. You will notice
several red boxes drawn - these are manipulators. You can pick a Modify\Move
tool and drag any of them. For example, if you drag a manipulator on the
"end-point" of the light, you can simply change a direction (target point) of the
light. The same way you can adjust spot-cones and light position:
Free Form Deformation.
Clear the scene by picking File\New. Create some curved shape (e.g. a
sphere, torus or something), or open a file with BMW from basic lessons (e.g. a
les3_06.z3d - preferable).
Expand options box in Modify\FFD tool. Set "Step" values for X, Y and Z to
2, 3 and 5 respectively. Then click on a BMW object. A Free form deformation
volume will be created. Move mouse cursor over this grid-volume to highlight
it. You can use "Hit-Ctrl" technique to highlight it too. Then switch this "FFD"
object to manipulators level. It will be drawn with red control points
over the grid. These are manipulators. Along world X axis there are two
manipulators in each row, three manipulators along world Y axis and five
manipulators along world Z axis in each row. This is what "Step X", "Step Y" and
"Step Z" ment. Drag any manipulator with Modify\Move tool and you will see
original object deformation. You can select some manipulators and move them
in selected mode too. "Hit-Ctrl" and "Hit-Shift" techniques are also available for
highlighting manipulators.
You can apply FFD to a group of selected vertices and/or to selected objects. Note that when you applied "FFD" you can not modify the mesh anylonger - you can not move individual vertices, create or delete elements.
Important: When you've done with FFD make sure to delete "FFD" object from scene. Then you can modify object in usual fashion.
When non-curved FFD was created on the mesh (our case), this FFD affects
mesh vertices that are in according "box" of the FFD (it's made of boxes: 1x2x4
above). When curved FFD created ("Curved" checkmark was On when applying),
each control point affects "whole row". Image below shows which "boxes" are
affected if according manipulator is dragged. Two right boxes in a bottom row
are not affected at all:
I've painted with red color how affection of single manipulator spreads over FFD
in curved mode. You can delete FFD and create new curved FFD over the mesh
and practice.