Hi all,
I was wondering if there´s any method of creating a lookat constraint for a camere, that keeps the camera levelled when orbiting around the target, like for example in …. any other 3d software?
I couldn´t find it in the manual or here in the forums.
Any help appreciated.

Thanks

what do you mean by ‘leveled’?
like a turntable?

place a null at the location you want to be the center of rotation
make the camera the child of the null
move the camera to where you want it to be
rotate the null

?

Hi Michael,
I mean, creating a targeted camera it is usually done with a lookat constraint with an upvector that keeps the cameras X-axis always parallel to the horizon. In Houdini however I can´t seem to get this working with the lookat parameter. Even if “use up vector” is on and orientation is set to 0,1,0, the camera rolls when I move it horizontally and it is not on Y=0. It´s the same behavior when I try to orient the cam with the orientation manipulators, and it´s very inconvenient. Am I missing something?

weird…there is something funk going on in H11.0.504…


anyway - just RMB on the Rotate parameter and select Lock
you should now be able to translate your camera around and get the behavoir you're after….


HTH

Thanks arctor, thats´s exactly what I was looking for.
Strange workflow though…

Edit: It turns out that the transform handle won´t align to the object anymore if rotation is locked. Why is it so hard to set up a simple camera in a 7000 $ software?

well there might just be something buggy going on…which happens in free software also…

on looking a bit deeper…
there IS something buggy here:

Houdini 11.0.504

create a null at the origin
add a camera
set the look at of the camera to be the null

using the parameter pane - move the camera around - the camera looks at the null and maintains it's orientation

using the move tool - the camera looks at the null, does not maintains it's orientation, the rotation parameters pop to new values each time you touch the jack

using the pose tool - the look at parameter gets blanked out!

very strange…I'll send something to support about it….

Hi arctor, I´m using build .547
It indeed shows the behavior you described, except all my rotation values stay at 0 although the camera rolls when moved by the handle. Weird.
I wonder why there´s no other thread in the forums about this, I mean the camera is the most fundamental component of a scene after all.
Anyway, thanks for your support!
I´ll just ignore the camera for now.

got this from support today:

Hi Michael,

I suppose you are using the camera handles to try to position your camera, rather than the move tool.
Camera Orientation Handles and Look Up objects can't be used simultaneously, this is because the Camera Orientation
Handle will move the look-at or eye point itself, in other words, it won't be looking at a null anymore…Actually if you notice,
the look-at path also gets cleared out if you are using the Orientation Hanlde
If you switch to translate and rotate handles (on the left side of the viewport) it should work fine.
Also, you can RMB on the camera handle and choose focus or frustum handles, these should also work.
As for the pose tool, if I select Object-specific handles, it will give me the Orientation Handles and we will fall in the above problem.
If I select Global Transform Handles, then it gives me translate an rotate handles, and it works fine…
Let me know if I am missing your point…
Cheers,

Silvina

I am using the transform handles, not the orientation handles. But either way, the camera rolls. I think I have to make a video… :roll:

No need…I can see some unexpected rotation values in there. I am submitting a bug for this.
Apologies for not noticing this before…

And as wolfwood said locking the rotate parameters gives you what you want in the meantime.

One aside, I kind of like the rotates in there when your camera is animated linearly along an object. Pretty cool. What I don't like is that the rotates can change whenever you touch the handle. Not good.

I love when the camera rotates when I want it to. :wink:

Does this file do what you want. It has a camera parented to a null object that is “looking at” another null. It also has the camera set as unselectable so you don't get the strange handle issue when using the handle tool. Now you can select and move the two null objects and there is no strange rotations.