CGI

Question 1

What is the importance of CG Math in Houdini workflows?

Answer 1

It connects mathematical concepts to practical applications in computer graphics.

Question 2

What are the main topics covered in the CG Math semester schedule?

Answer 2

• Numeral systems
• Trigonometry
• Vectors
• Matrices
• VEX
• Rendering

Question 3

What is an Integer?

Answer 3

Whole numbers (positive, negative, or zero).

Question 4

What defines Rational Numbers?

Answer 4

Fractions like ½, ¼.

Question 5

What are Real Numbers?

Answer 5

Numbers that include all decimals, e.g., 3.14.

Question 6

How are different types of numbers used in Houdini?

Answer 6

They define geometry attributes such as position, color, scale.

Question 7

What is the 2D Cartesian Coordinate System?

Answer 7

(x, y)

Question 8

What is the 3D Cartesian Coordinate System?

Answer 8

(x, y, z)

Question 9

What is the difference between left-handed and right-handed coordinate systems?

Answer 9

Left-handed (Unreal Engine) vs. right-handed (Houdini uses Y-Up).

Question 10

What does the command @P += {1, 2, 3}; do in Houdini?

Answer 10

Moves an object in 3D space by adding 1 unit to X, 2 to Y, and 3 to Z.

Question 11

What are the basic math operations covered?

Answer 11

• Negation
• Multiplication
• Division
• Powers
• Roots

Question 12

How can you animate the size of a sphere in Houdini?

Answer 12

Using the power curve: f@scale = pow(@Time, 2);

Question 13

What is Summation in mathematics?

Answer 13

Adding values (∑).

Question 14

What is Product in mathematics?

Answer 14

Multiplying values (∏).

Question 15

What does Percentage represent?

Answer 15

Scaling a value between 0 and 1 to 0–100%.

Question 16

How do you normalize the height of points based on percentage?

Answer 16

f@percentage = fit(@P.y, 0, 10, 0, 1) * 100;

Question 17

What does the Clamp function do?

Answer 17

Limits a value to a specific range.

Question 18

What is the purpose of the Fit function?

Answer 18

Remaps a range to another range.

Question 19

What does the Modulo operation (%) do?

Answer 19

Finds remainders.

Question 20

What are the basic geometrical structures in Houdini?

Answer 20

• Points
• Vertices
• Primitives

Question 21

Why are triangles commonly used in geometry?

Answer 21

Simplicity and guaranteed planarity.

Question 22

What are the Houdini data types introduced?

Answer 22

• int
• float
• vector
• matrix
• string

Question 23

What does v@dir = {1, 0, 0}; represent in Houdini?

Answer 23

A vector pointing along the X-axis.

Question 24

What trigonometric functions are covered?

Answer 24

• Sine
• Cosine
• Tangent

Question 25

What types of noise are discussed?

Answer 25

* Perlin * Simplex * Fractal

Question 26

How can you drive movement with sine and cosine in Houdini?

Answer 26

@P.y = sin(@Time);

Question 27

What are the vector operations covered?

Answer 27

* Addition * Dot product * Cross product * Normalization

Question 28

What is the purpose of matrices in Houdini?

Answer 28

For transformations (rotation, scaling, translation).

Question 29

How do you rotate points around the Y-axis?

Answer 29

matrix3 rot; rotate(rot, radians(45), {0, 1, 0}); @P *= rot;

Question 30

What does VEX programming allow in Houdini?

Answer 30

Procedural and efficient manipulation of geometry.

Question 31

How can you add random noise to a position in VEX?

Answer 31

@P += noise(@P) * 0.1;

Question 32

What are the types of transformations in Houdini?

Answer 32

* Scaling * Translating * Rotating

Question 33

What is the significance of the order in matrix multiplication?

Answer 33

It affects the final transformation result.

Question 34

What does raytracing in rendering involve?

Answer 34

Calculating light reflection and shadows.

Question 35

What are the types of curves explained?

Answer 35

* Bezier curves * Polynomial curves

Question 36

What algorithms are included in Computational Geometry?

Answer 36

* Voronoi fracture * Triangulation

Question 37

How can you break an object into pieces in Houdini?

Answer 37

Using the Voronoi Fracture SOP.