Animation question

bobrsta

I'm stumped in an animation I'm trying to create-

I'm starting off with a scene of a building section in parallel projection using one of the standard camera views (front, in this particular instance). It may be important to note that I am not using SU section tool to create the section, rather I have imported the architect's section at that point into SU as DWG (grouped and assigned to layer). (I'm laying out the architect's plan in 3D space in SU, so that I have the basement level, 1st floor and 2nd floor all aligned but separated vertically by the difference in floor elevation, and then I've also brought in the various section cuts from the Architect. So, I have a "model" of 2D architectural sheets arrayed in space.) I want to animate from this parallel view to perspective and then start rotation of the "model". But, when I select "perspective" from the camera menu, the the camera position jumps way away from the previous location in parallel view. This behavior does not occur in the opposite direction (perspective to parallel). Am I doing something wrong or is what I'm trying just not possible?

I tried to upload the model but it is apparently too large a file...

It can be downloaded from dropbox here

https://www.dropbox.com/s/bq0gej1h65rcjm0/39%20Strand%20Beach.skp?dl=0

Thanks in advance for the help!

Bob

pbacot

The apparent jump in camera position between the two projections is common. You'll just have to find a view for the second scene (I assume you are animating scene transitions) that suits your purpose. If you find making the transition the other way works, perhaps switching the position of scenes in your sequence will work.

Rich O Brien

You'll always get a camera jump as you switch from Parallel to Perspective. There's no transition between orthographic and perspective.

The only method I know would be to duplicate the last orthographic view by creating a new scene whilst in that viewpoint. Then set the new scene to perspective, adjusting the zoom to match the previous and then update the scene. Then create the next scene view.

Box

Edit: How on earth did my post get here.
For some reason something I posted in another thread appeared here, as it was unrelated I have deleted it.

bobrsta

I duplicated the scene as you suggested and fiddled a bit to get the view the same (or very close). The camera still leaps away when switching from one view to another, but at least I have something I can work with after exporting the animation, by cutting out the offending transition.

This behavior of view changing, in animation, between projection changes seems odd though.

Thanks!

Rich O Brien

An orthographic camera has no field of view unlike a perspective camera. So if you transition from a orthographic to a perspective the shift is because the field of view introduces depth to the scene.

If you transition back to orthographic from the perspective scene you'll see this increased as the camera removes the depth.