This document discusses 3D transformations including reflection and shearing. It begins with an overview of 3D reflection about the XY, XZ, and YZ planes. It then describes how to perform reflection about any plane using a series of translation, rotation, reflection, and inverse transformations. Examples of 3D shearing about the X, Y, and Z axes are also provided. The document concludes with a numerical example of finding the reflection matrix for a plane through the origin with normal vector I+J+K.
3D REFLECTION
By: ArvindKumar
3D
3D Reflection about XY-Plane
1000
0100
0010
0001
1
'
'
'
z
y
x
MXY
z
y
x
4.
3D REFLECTION
By: ArvindKumar
3D
3D Reflection about XZ-Plane
z
y
x
1000
0100
0010
0001
1
'
'
'
z
y
x
MXZ
5.
3D REFLECTION
By: ArvindKumar
3D
3D Reflection about YZ-Plane
z
y
x
1000
0100
0010
0001
1
'
'
'
z
y
x
MYZ
6.
3D REFLECTION wrtANY PLANE
By: Arvind Kumar
3D
Steps to be Follows
1. Translate, that lies in the reflection plane to the origin.
2. Rotate the Normal Vector to the reflection plane at the
origin until coincident with z axis.
3. Reflect the object through xy Plane.
4. Perform inverse Rotation transformation
5. Perform inverse Translation transformation
Rxy-1
T-1
Rxy
T
Mxy
TRRT xyxy xyM M11
7.
3D REFLECTION wrtANY PLANE
By: Arvind Kumar
3D
Step-1 Translation
1000
100
010
001
tz
ty
tx
T
8.
3D REFLECTION wrtANY PLANE
By: Arvind Kumar
3D
Step-2 Rotation about xy plane
let the normal vector :
N= 𝒏𝟏𝒊 + 𝒏𝟐 𝒋 + 𝒏𝟑 𝒌
N= 𝒏𝟏 𝟐 + 𝒏𝟐 𝟐 + 𝒏𝟑 𝟐 ,
1000
0
321
0
23
0
0
3121
N
n
N
n
N
n
nn
N
nn
N
nn
N
Rxy
2322 nn
3D REFLECTION wrtANY PLANE
By: Arvind Kumar
3D
Step-4 Inverse Rotation
1000
0
3231
0
2321
0
1
0
1
N
nn
N
nn
N
nn
N
nn
N
n
N
Rxy
11.
3D REFLECTION wrtANY PLANE
By: Arvind Kumar
3D
Step-5 Inverse Translation
1000
100
010
001
1
tz
ty
tx
T
12.
Numerical
By: Arvind Kumar
3D
Q1.Find the matrix for the mirror reflection wrt the
plane passing through the origin and having a
normal vector whose direction is N= I+J+K.
Solution:
Here p0 (0,0,0) and plane passes through the origin .
Hence translation is not necessary.
the normal vector : N= I + J + K
Here, n1 = 1, n2= 1, n3=1
𝑵 = 𝟑 , λ = 𝟐
3D Shearing
By: ArvindKumar
3D
3D Shearing about X-Axis
3D
11000
010
001
0001
1
'
'
'
z
y
x
b
a
z
y
x
SHx
17.
3D Shearing
By: ArvindKumar
3D
3D Shearing about Y-Axis
3D
11000
010
0010
001
1
'
'
'
z
y
x
b
a
z
y
x
SHy
18.
3D Shearing
By: ArvindKumar
3D
3D Shearing about Z-Axis
3D
11000
0100
010
001
1
'
'
'
z
y
x
b
a
z
y
x
SHz