Scheimpflug: Simulating a shift lens

   11321   9   2
User Avatar
Member
214 posts
Joined: Dec. 2009
Offline
Hey all,

I want to simulate a shift lens with houdini's camera. This means in a
nutshell I want to manipulate the picture plane separately from
the lens plane.

I thought, I remember from the v4 or v5 days that houdini already
can do that out of the box. But it seems, that I can't find the appropriate
parameters.

I already checked out the docs and the rendering paramters.
No luck so far.

Any hints much appreciated

Cheers,
Marc
User Avatar
Member
941 posts
Joined: July 2005
Offline
bollili
I want to simulate a shift lens with houdini's camera. This means in a
nutshell I want to manipulate the picture plane separately from
the lens plane.

I thought, I remember from the v4 or v5 days that houdini already
can do that out of the box. But it seems, that I can't find the appropriate
parameters.

Hmm… maybe you're thinking of the camera paramters that let you scale, shift, and crop the image plane (cam>View>Screen ), but I can't think of any built-in “tilt” or rotation mechanism that would let you do what a real ts lens does.
Mario Marengo
Senior Developer at Folks VFX [folksvfx.com] in Toronto, Canada.
User Avatar
Member
729 posts
Joined: July 2005
Offline
Hmmn, you can do “lateral” movements with the Screen Window X/Y option, is that what you had in mind? Pretty certain Houdini 4 or 5 didn't have anything fancier.

User Avatar
Member
214 posts
Joined: Dec. 2009
Offline
Oh man, I can't believe that I've overlooked this
Thanks guys!

But one problem remains. The background image does not transform with these camera parameters. I want to add animation to architectural stills that were shot with a shifted lens and it's real pain to align them.

Is there any recommended workflow for this task?
Or just another option that will transform the background image I don't know…


Cheers,
Marc
User Avatar
Member
214 posts
Joined: Dec. 2009
Offline
Sorry, I just realized my description is totally wrong. It seems I don't get my head around this…

Actually, the background DOES transform together with the objects in the scene. I want to turn that off.


In the display options i found the checkbox called “Background -> 3D Viewport -> Apply Zoom to Background”.
When I uncheck it, the background is indeed not transformed. But, the camera looses its selection in the viewport and isn't active anymore.
If I reselect the camera again as the active one, the checkbox will be automatically selected (and the background is transformed again) - dough.
If I lock the camera to the view, this checkbox cannot be unchecked at all.


Cheers,
Marc
User Avatar
Member
729 posts
Joined: July 2005
Offline
Why not do it in post instead?
User Avatar
Member
214 posts
Joined: Dec. 2009
Offline
I can't do it in the post afterwards, because the model uses parts of the background projected from the camera. But you put me on the track!

I use a wireframe render from wren in cops and composite it over the bg. That's not really realtime, but it's fast enough for previewing…

Thanks mate!

I think will submit an rfe that “apply zoom to bg” and “lock camera to light/view” are not mutually exclusive.

Cheers,
Marc
User Avatar
Member
214 posts
Joined: Dec. 2009
Offline
RFE (ID=41550) submitted.

Cheers,

Marc
User Avatar
Member
2 posts
Joined: Jan. 2011
Offline
You wouldn't go for a doctor for prescription while using this product. Because it is absolutely reliable & needn't doctors advice.
Contact Lenses [contact-lenses-without-prescription.com]
User Avatar
Member
279 posts
Joined: July 2005
Offline
I totally agree with Gregg's post…. even though it's all spammy and stuff.
  • Quick Links