Look-At Constraint

[vizfx]

Hi.

I have a problem with “Look-At Constraint”. I have some textured planes in my scene and I want them to face constantly to the (moving) camera. They must rotate only around the Z axis. I`ve used “Look-At Constraint” but it rotates the planes around all the axis to keep the normal perpendicular to the camera position.

I need to do this with the tools within Max because later I have to export them to a 3rd party engine which may not support some plugins.

I know that this should be the choice but I think I`ve missed a setting somewhere.

If you have any ideas please let me know.

Best regards.

Mihai

[vizfx]

Hi again.

It`s something similar to RPC plugin in which this job is very easy.

For the moment I`m looking even to scripts or plugins, maybe they can help me.

[Koper]

yeah, there is a setting called 'keep initial offset'. its a check box, just check it. somebody else will have to tell you how to set it so that it doesn't rotate with the x-axis, for when the camera changes height.

 

hope it helps

[olbo]

Heya Mihai,

 

just take a look at scriptspot.com and do a search for billboard ...

I guess you'll find what you need. ;o)

 

 

 

take care

Oleg

[vizfx]

Many thanks for the replies.

"Keep initial offset" does the trick only if the camera is at exact position on Z axis as the plane`s pivot. This can be seen when the camera is close to the object.

For the moment it`s ok but I`m still searching for better solutions.

[mskin]

don't know if this helps. but i create a dummy object directly below the camera at 6'6" off of ground and use that as the look at controller. it follows my camera all around the scene.

[jvlive]

the dummy idea is good, but one question: if it follows the camera around, how do you keep the dummy at constant height while the camera changes its z-position?...

 

...... an idea came to mind: copy the camera path (i assume there's one) to use as the dummy's path, move all vertices to same z-position... but i'm pretty sure there's a better solution than this, not really sure if this would even work.

[mskin]

in my experience, which isn't vast, its ok if the dummy is slightly off from the cameras exact x,y position by a couple of feet or so. the difference has been unnoticeable in my animations. I get more caught up in the fact that a trees appearance doesn't change at all as the plane rotates to follow the camera. its like the angle changes, but the view of the tree remains constant.

[Tyorl]

the dummy idea is good, but one question: if it follows the camera around, how do you keep the dummy at constant height while the camera changes its z-position?...

 

...... an idea came to mind: copy the camera path (i assume there's one) to use as the dummy's path, move all vertices to same z-position... but i'm pretty sure there's a better solution than this, not really sure if this would even work.

I think u should try Limit controller. Just Float Limit for example

[vizwhiz]

constrain The 'dummy' To rotate ONLY in The Z axis

 

**

 

someone should write a book or Tutorial:

 

"Constraints for Dummys'

 

i would definately buy it and read it

 

**

 

Thanks

 

Randy

[Nils Norgren]

don't know if this helps. but i create a dummy object directly below the camera at 6'6" off of ground and use that as the look at controller. it follows my camera all around the scene.

 

Mskin's method has worked for me, to get the dummy to not follow the camera in the Z, just go into the Heirarchy panel, Link info, and un-check inherit z, the dummy will remain planar in the z but follow the camera around in the x and y.

 

Hope this helps

 

Nils Norgren

[vizfx]

Hi to all again, this time with a big smile because from all the posted ideas finally came out the lucky shoot.

So, I`ve made a point helper object which is linked to my camera to follow it`s movement. At the Link Info/Inherit I`ve unchecked move on Z axis, so my point follows the camera but doesn`t move on the vertical axis. The final move is to set “Look at controller” to target the point with “Keep initial offset”.

P.S. The point must be at the same Z axis value as the pivot points of my planes.

Best regards.

Mihai

[batteryoperatedlettuce]

there is a tutorial for this in max 7+ any rate.

 

I'm not sure if I'm allowed to post the script here, but if you don't have it you can pm me and I'll pm you back the script with a walkthrough on how to run it. It's pretty barebones, but it works.

[jvlive]

....you learn something new everyday....