Week - 5 - Checking and correcting the Normals

Aim-

• Write a code to display normal as explained in class.
• Create a widget containing two buttons for “reverse normals” and “normal off”.
• Also assign these procedures to keyboard buttons of your choice.
• check the null case also.

Code and Explanation-

CREATING Widget

#setting a window

set a .window
catch {destroy $a}
toplevel $a -class TopLevel

#managing window size and name

wm title $a "Normals"
wm geometry $a 250x70+100+500
wm resizable $a 0 0
wm deiconify $a

#assigning buttons

button $a.01 -text " Reverse Normals" -command {*createmark elements 1 "displayed" ; *normalsreverse elements 1} ;
place $a.01 -x 20 -y 20 -width 100 -height 30

button $a.02 -text " Normals Off" -command {*createmark elements 1 "displayed" ; *normalsoff} ;
place $a.02 -x 130 -y 20 -width 100 -height 30.

Procedure-

• *setnormalsdisplaytpeis used to display the type of visualization whether with direction of normal (0) or color(1)
• Then the elements displayed in were selected using *createmarkcommand.
• Normals were displayed for the selected element with color representation using*normalsdisplay elems. 
• Functions were created for the reversing the normals and select the elements  using proc and these functions are called by assigning the respective buttons. 
• To reverse the normals of the selected elements *normalsreverse command is used.
• hm_framework is used to create a separate tab.

Output-

1. Shortcut key select shift + ~.

2. Now after running widget code.