I'm trying to rig my test character in APEX, but I am stuck at the LookAt part.

In Apex edit graph there is transform__lookat, but I didn't manage to make it work, and there is no documentation for it.

I followed up APEX rigging Masterclass, there is just pointed to the finished setup in the Lucha and chicken file, which I managed to rip off and use in my setup.

Is currently the only way to rip off finished rigs to be able to make basic rigs for simple characters?


looking forward to more user-friendly modular nodes for building the rigs.

We've started slowly adding docs but to help you get going in the mean time:

The inxform matrix is rotated so that it points its -Z axis from its position to the position of the lookat transform, while orienting its +Y axis towards the position of lookup.

you can do pretty much anything you'd want with apex in it's current stage.
Apex is literally just a bunch of different houdini-contexts thrown together into a system that allows for functions to be fired through attributes. Quite amazing.

I personally was not able to get the Look-at working, because I did not understand the 3 matrix inputs it required and I dislike finding anything in the currently existing rigs. I'm more used to a 3 vector input look-at constraint. There is probably a good reason for it requiring matrices.

But you are always able to create your own look-at if you'd want. here is an example I quickly build using vector inputs.

I took another look at it "no pun intended".

And I believe the last matrix is a point in space that is used to determine the "look-up".

I've got results when modifying the "translate" aspect of the matrix upwards.

I'm not sure if this is correct as I don't know why the look-up vector requires X Y and Z vectors.

I think it's just because you're often dealing with joint transforms in rigs, so it's more convenient to directly wire the entire matrix into the look at without needing extra nodes to extra their positions first.

For me the best way to implement it was to use the APEX autorigcomponent, set to 'lookat'. Once I got that working I could study the resulting graph through unpacking it.