SketchUp and KeyShot FOV and Focal Length don't match

[chippwalters]

It turns out a Focal Length of 25mm (FOV 70.84 deg) translates (via the KeyShot plugin) to 5.763 in KeyShot, which (FOV of 144.5)

So, when the camera imports from SketchUp into KeyShot, it looks like this:
1) SketchUp with Camera INFO
2) SketchUp Camera as Imported into KeyShot
3) Eyeballed changing of FOV in KeyShot


I believe the only thing OFF in KeyShot is the FOV/Focal Length. Any idea on how one would go about converting it correctly? Thanks for shedding any light on this.

[edwardo]

Is this a scale issue? Has your model been imported with the same unit?

[guest84672]

It is not a scale issue since he's using the plugin. Development just identified the issue and confirmed that there is a mis-calculation. A fix should be available shortly.

[edwardo]

Cool.... I only asked because I had something similar happen many moons ago whilst trying to render an interior, until I realised it was the size of a tiny matchbox!

[chippwalters]

This from a developer of SU plugins on another forum where I posted the same question.


had a look at the code and can see what the issue is...
This is how SU states it works...

Camera.aspect_ratio=SketchUp 6.0+
The aspect_ratio= method is used to set the aspect ratio for a Camera. Changing this value will cause SketchUp to show gray bars over the screen to show the resulting view.

If you set the value to 0.0, then the aspect ratio of the Camera will match the aspect ratio of its View.


I think the problem is that KeyShot uses this method to collect data from SU.

why might that be a problem?

Unless you use one of the preset Advanced Cameras, or a plugin, SU returns 0.0 for the aspect ratio, which is then used to calculate the parameters in KS, this would account for a variance.
e.g. if I have my window set at 1.414, SU reports it as 0.0
if I use the 16mm camera aperture, SU reports 1.37

I don't have KS, so I can't test if KeyShot works correctly with an Advanced Camera, but the plugin code suggests it would.

If it does, then a small addition in the ruby, may allow it work for the Standard SU camera...

Can you test with an AC, to confirm/dispel the thinking?

and/or you could try modifying the plugin...

I'll PM some code that may work if you want...
john

[chippwalters]

There's a decent thread on why this is not working, plus a possible 'fuzzy' workaround at:
http://sketchucation.com/forums/viewtopic.php?f=15&t=61933&p=566779#p566779