Artye - I understand your point and have read a large portion of the link Mestela linked too, anyhow Mestela was wonderful at explaining dot products, that when you posted I got sorta side winded to the goal of understanding cross product.

What value can I assign to the temp attribute myvec so I can visualize the cross product considering the mydot attribute has the normal assigned ?

whatever you want, eg

vector myvec = cross(@N, {0,1,0});
v@foo = myvec;

Then add a visualizer, and set it to display @foo in whatever method you see fit (tho you'd probably expect marker, vector):

The vector trails are all the right angle for the points, correct ? I'm assuming if I want to visualize the cross product for the primitives I have to promote the attribute to primitives ?



I'd really like to visualize the point and or primitive two angles values to see how the right angle completes everything in other words see math which Houdini is calculating for the cross product, to drive the concept home ? I feel I'm close to understanding thanks to, the wonderful posts by mestela.

That is since the cross product is the multiplied of the two vectors which gives the right angle the yellow vector visualization as see in the image above and in mestela image is that of the two vector multiplied

The visualise works fine on prims too, just set it to class:primitives.

Re seeing all 3 axis at once, a nice trick is to set the style to ‘axes’ mode, and specify the 3 vectors separated by spaces. Now you can fiddle with the vectors, and see them update in realtime:

If you are stuck with Math in Houdini (like i am/was) i want to make another suggestion: take a small break from Houdini and dive into the Processing language. Then find Daniel Shiffman's channel on Youtube and start studying his “The Nature of Code” book and video's. Highly recommended for understanding the basics of Vector math. Its got awesome practical examples from starting from the ground up. Daniel is an amazing teacher.

I watched the vector tutorial from Daniel Shiffman's channel, pretty good although I knew what a vector was. I have a series of questions I'd just like to ask someone who has some time to answer as so I can understand.