 |
This task shows you how to hide already hidden elements when performing
a selection, thus selecting only
the visible elements in a subdivision surface. |
 |
Open the
ModifySurface5.CATPart
document.
The Show hidden lines
in dashed lines option is selected in
Tools > Options > Shape >
Imagine & Shape > Display tab,
Base Mesh area. |
 |
-
Click Modification
in the Modification toolbar.
-
Select Subdivision Surface.1. You can see that the hidden edges and vertices of the mesh are also
visible and can be selected. Selection of visible elements thus becomes
difficult. In this case the View and Selection All
mode has been clicked
in the Operations toolbar.
-
Click View and Selection All
in the Operations toolbar. The View and Selection
All icon state changes to
View All and Selection Front
.
You can see that all the hidden
(back) edges of the subdivision surface are grayed out and cannot be
picked.
-
Click View All and Selection
Front
in the Operations toolbar. The View All and Selection
Front
icon state now changes to
View and Selection Front
.
You can see that all the hidden
edges covered by the subdivision surface are no longer visible. Some part
of these hidden edges which is not covered by the subdivision are still visible
in the mesh, but they are grayed out and cannot be picked.
To go back to the initial state, click it again.
-
Rotate the subdivision surface or change its shape
(in case of a modification). You can see that as the surface moves the
relevant hidden edges are not visible. The selected edge remains
highlighted and selectable even after rotation.
|
 |
- If the All Elements Selection
icon
is activated, only pickable elements will be selected (not grayed
out elements), provided the View All and Selection Front
or
View and Selection Front
modes are activated.
- The visualization of the three help text level icons can
either be on the
same icon cyclically or in an expandable separate toolbar.
This depends on the
option chosen in Tools > Options > Shape > Imagine
& Shape > General tab, Command
Options Menu Mode area.
- If Show hidden lines
in dashed lines option is cleared, hidden lines are
displayed with the same settings as the
base mesh elements defined in
Tools > Options > Shape >
Imagine & Shape > Display tab,
Base Mesh area. Depending on the
different states of View and Selection mode
command, the subdivision surface is as seen:
 |
View and Selection All
 |
 |
View All and Selection Front
 |
 |
View and Selection Front
 |
- In some case, it may happen that some edges are seen
though they are behind the face. This is because the surface has
such faces with the normal directed towards you and not towards
the back of the screen as it is in most of the cases.
|
 |