[VEX for Algorithmic Design] E14 _ Quaternion Basics

This is a new series I've started explaining the basics of VEX for algorithmic design / procedural modeling which I'm using on daily basis.
In this 14th episode, I'm explaining the basics of quaternion, how you can use it for rotational transformation in Houdini with VEX together with some examples.
I've also started a Patreon, it would be great if I could get your support to continue creating tutorial contents.
00:00:00 Intro / What is Quaternion?
00:04:23 Declare Quaternion
00:10:41 Rotation with Quaternion
00:16:53 Exercise - Rotate Object
00:23:23 Exercise - Spiral Rotation
00:27:54 Euler to Quaternion
00:42:56 Quaternion to Euler
00:47:13 Quaternion Blend with Slerp
01:00:20 Exercise - Rotational Animation
01:19:11 Orient Vector with Dihedral
01:24:19 Exercise - Animation with Dihedral
01:39:02 Next Topic - Matrices Basics
[Project Data Downloads]
github.com/jhorikawa/VEXForAl...
[Patreon page]
/ junichirohorikawa
[Episodes]
Episode 1 - Attribute Basics: • [VEX for Algorithmic D...
Episode 2 - Group Basics: • [VEX for Algorithmic D...
Episode 3 - Parameter Basics: • [VEX for Algorithmic D...
Episode 4 - Variables and Operations: • [VEX for Algorithmic D...
Episode 5 - Array: • [VEX for Algorithmic D...
Episode 6 - Strings: • [VEX for Algorithmic D...
Episode 7 - Loop: • [VEX for Algorithmic D...
Episode 8 - Conditional: • [VEX for Algorithmic D...
Episode 9 - Function: • [VEX for Algorithmic D...
Episode 10 - Volume Basics: • [VEX for Algorithmic D...
Episode 11 - Dictionary Basics: • [VEX for Algorithmic D...
Episode 12 - Vector Basics: • [VEX for Algorithmic D...
Episode 13 - Trigonometry Basics: • [VEX for Algorithmic D...
Episode 14 - Quaternion Basics: • [VEX for Algorithmic D...
Episode 15 - Matrix Basics 1: • [VEX for Algorithmic D...
Episode 16 - Geometry Functions: • [VEX for Algorithmic D...
Episode 17 - Intrinsic Attribute: • [VEX for Algorithmic D...
Episode 18 - Randomness Basics: • [VEX for Algorithmic D...
Episode 19 - Noise Basics: • [VEX for Algorithmic D...
Episode 20 - Solver Basics: • [VEX for Algorithmic D...
Episode 21 - Half-Edge Basics: • [VEX for Algorithmic D...
Episode 22 - Remapping Basics: • [VEX for Algorithmic D...
Episode 23 - SDF Basics: • [VEX for Algorithmic D...
Episode 24 - Force Basics: • [VEX for Algorithmic D...
Episode 25 - Force Extended: • [VEX for Algorithmic D...
Episode 26 - Recursion Basics: • [VEX for Algorithmic D...
[Houdini Related Playlists]
VEX for Algorithmic Design: • VEX for Algorithmic De...
Houdini Tutorial: • Houdini Tutorials
Houdini Algorithmic Live: • Houdini Algorithmic Live
Houdini Snippets: • Houdini Snippets
Houdini Tips: • Playlist
[Portal Page]
Facebook Page: / parametricproceduralho...
[Books]
Algorithmic Design Workbook with Houdini: gum.co/GOZFw
Tiling Pattern with Houdini: gumroad.com/l/OVDgY
Algorithmic Design with Houdini: www.bnn.co.jp/books/9788/
Books on BOOTH: orangejellies.booth.pm/
[Contact]
Twitter: / jhorikawa_err

[@apo6199]

The basic math knowledge really helps a lot to learn parametric design, please do more of these kinds of shares!thank you so much for this great series!

[@jesusfreak_x3l]

After many years of 3D and Houdini I finally get the courage to face quaternions thanks you. And it is not even that scary :-) Thank you Professor.

[@VitaminSoup]

The was a little math trick there that never occurred to me. Dividing the result of (y % x) by x give you a value between 0-1. Thanks!

[@gtrzdaddy]

First of all I have a pretty bad case of ADHD, but your lessons, even with the monotonic narration, was extremely enjoyable, immersive, and kept me in my desk, while improving my Houdini skills tremendously! Thank you for all the great contents!

[@Alain21312131]

I'm certain that you know this, but a nice way to have the orient attribute computed from a transform node like you are doing around 1h06m is to actually create the orient attribute beforehand. The transform will automatically modify the existing orient correctly. And then you can attribute promote it to detail using the iteration value. I do realize that you showed this using VEX since this is the focus at hand, but I still think this is worth noting. Especially if we are daisy-chaining multiple transform. Keep up with the awesome content !

[@MrUltraVic]

Oh my gosh! Thank you so much for this comment.....I was trying so hard to get all this to work right for exporting point cloud info to unreal.

[@wensenliang1019]

can't wait for the matrix selections.

[@fazlgumus9421]

Thank u Mr Horikawa

[@maurypb]

Great lesson, Professor Horikawa. Thank-you!

[@kitma5747]

Thank so much for the detailed explanation.

[@jw4412]

Thanks you sir!

[@avi4fxonly]

thank u so much for such a nice explanation

[@peterprickarz3135]

Awesome, thanks a lot for all the dope content!

[@ularrarte]

Came here after doing yout tutotial. Its dope!

[@peterprickarz3135]

@@ularrarte Damn, the world is small. Thanks!

[@sams_3d_stuff]

Thank you Master.

[@Ooorient]

thank you for these treatures!!!!!!!

[@graphic-nations]

Amazing thank you

[@srinavin]

Thank you

[@MONEYVAL9]

Class in session.

[@decanecaudeoscar6961]

i love these 3D courses where the grab guizmo is barely used in 15 hours of training

[@bass_journey]

Sophisticated solution, I still can't wrap around my mind totally on how you mapped each iteration to a certain frame range when it comes to the brick rotation at the end. Anyone can explain that to me :) ?

[@AnsonSavage]

Yeah! So, there's 5 iterations, right? So he finds the range of a single iteration by taking the number of frames ($FEND) and divides by the number of iterations. Say there's 100 frames. Then range would be 100/5 = 20. Next, he maps t to a value between zero and one. % means modulus. @Frame % range gives how far into that iteration's range the current frame is. E.g., frame 35 % 20 would be 15. He then divides by range (20) to get 0.75, indicating that on frame 35, the t value is 0.75 or 75% of the way through that iteration. The only thing left is to determine which iteration. He does this by dividing the @Frame by the range and flooring it. So, on frame 35, we'd have 35/20 = 1.75, but floor(1.75) is 1, so this indicates it's on iteration 1 (iteration 0 is the first iteration). He then uses % num to ensure that, once the iteration gets up to 5, it is zero instead. Instead of 0, 1, 2, 3, 4, 5, it would be 0, 1, 2, 3, 4 ,0.

[@bass_journey]

@@AnsonSavagethanks for the time to write this down. I will take some time this weekend to go through this again and check your explanation . I still have the exercises saved. Never managed to understand this last part fully, although could see how it worked. Cheers