
Discover how math drives visual effects in Houdini FX, guiding animation, velocity and rotation control, and simulation behavior through curve creation for practical projects.
Explore how vectors carry direction and magnitude in Houdini fx, covering velocity, acceleration, and force, and learn to interpret vector attributes with x, y, z components and their length.
Dot product equals the product of vector lengths times the cosine of their angle, yielding a scalar. Normalize vectors to unit length so this equals cosine and shows motion direction.
Calculate the angle between two vectors in Houdini by constructing two lines as vectors, normalizing them, computing the cosine of their angle, and converting from radians to degrees.
Explore how dot product and velocity direction govern forces in a four-plane flip fluid setup, steering particles along planes 1 to 4 with a dynamic force attribute and velocity normalization.
Use dot product and normalized velocity to compute force directions in a flip fluid, guiding particles between planes based on angle thresholds.
Explore the cross product definition, showing how normalizing the cross product yields a direction perpendicular to the plane of two vectors, useful for collision responses and circular motion in graphics.
Explore how to use cross product to drive force dynamics in Houdini FX, creating circular motion by aligning a normalized cross-product force with particle velocity, and controlling angle and speed.
Learn to generate and update a random vector in Houdini FX with round-based components, frame-based seeding every 10 frames, and amplitude control for dynamic particle motion.
Explore driving particle motion with a cross force in Houdini FX, using time-based amplitude, sine and round functions for per-particle randomness, and frame-driven updates.
Discover how to reorient curves in Houdini FX vol 1 by aligning particle emissions from origin along the positive X axis, using for-each networks, transform nodes, and area filtering.
Learn to emit particles in Houdini with frame-based control: set initial velocity, life, and color attributes, and release groups every 24 frames using primitive ids.
Explore how to use the matrix to store rotation information and apply it to velocity and direction attributes, orienting curves and geometry with rotation matrices in Houdini FX.
Learn to create and apply a 3x3 rotation matrix from two vectors to reorient curves, export matrices, and drive particle direction using orientation attributes.
Rotate a velocity vector with a matrix around a chosen axis, normalize it, and apply random rotation to steer particles emitted from a surface in Houdini FX.
Explore how the sine function in Houdini FX exhibits periodic behavior, defining period, initial phase, amplitude, and decay to shape waves across 0–360 degrees and frames.
Explore generating a grid of lines driven by two sine waves using a single function. Adjust amplitude, period, decay, and time-based animation for varied motion across the lines.
Learn to model decay in Houdini FX using two solver methods: decay by percent and decay by subtraction, including frame-based calculations, clamping to zero, and practical examples like temperature cooling.
Create a decay solver in Houdini FX to transfer temperature and color from a grid to objects, visualizing cooling, decay, and smoke or particle effects.
Manipulate the 0–1 range in Houdini FX to build complex line and curve shapes using amplitude, curvature, and exponential decay, including sharp and smooth mountain profiles.
Hello Everyone,
Description: This training demonstrates the big role of Math in creating visual effects and controlling the simulation behavior in Houdini FX animation software. I will cover many of the most popular math topics in computer graphics and I will show you how to apply these concepts inside Houdini with some cool projects. I will focus on what we need to know from math for using in VFX without diving into complex mathematical details as this training is not about pure math. I will show you how the Dot product can be used with the Flip Fluid, and how to create windy curves using the Cross product, and how the Matrices can determine the velocity and store the rotation data.....and many other features of using Math in Houdini.
Lesson plan :
1. Introduction to vectors – What is the vectors and, why we need it in math and physic and CG ?.
2. Dot product definition – Introduction to Dot product equation in math: input, return, formula, spatial situation, deficiency of Dot product .
3. Dot product and angle calculate – Simple example in Houdini for using Dot product to calculate angle between two geometry.
4. Dot product inside flip fluid 01 – Create custom force attribute for controlling fluid behavior.
5. Dot product inside flip fluid 02 – Solving deficiency in Dot product and final behavior test.
6. Cross Product definition – Introduction to Cross product equation: what we need to know about Cross Product for using in CG, and
what we don't need ?.
7. Cross Product and particles 01 – Aiming dynamic force in particles by Cross product for creating windy curves (like frozen animation film).
8. Cross Product and particles 02 – Adding randomizing vector to Cross product and update vector every 10 frames.
9. Cross Product and particles 03 – Add amplitude to Cross Product direction vector and final simulation.
10. Cross Product and particles 04 – Reorient all curves by one direction using For each SOP.
11. Cross Product and particles 05 – Emitting particles from curves and creating advanced time manipulating expressions with time shift node .
12. Matrix 01 – Rotate the attributes by Matrix to save the orientation after rotation.
13. Matrix 02 – Generate Matrix using Align Vex Node and create attributes to store reorientation Matrix in, Create advanced reorient system using Matrices and For Each.
14. Matrix 03 – Without Matrix it will need a code of 20 lines to do this effect, Modify particles velocity vector by rotation matrix.
15. Sine Function 01 – What is the sine function parts in math.
16. Sine Function 02 – Adding two sine wave to simple grid.
17. Decay Solver 01 – What is the decay and what are the types of decay in life.
18. Decay Solver 02 – Creating decay solver simulation in Houdini to decay physical attributes like fluid's temperature, viscosity and cloth's wetness….etc.
19. Manipulate Rang[0-1] – Creating 10 different complex shapes from simple point number expression.