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:

SketchUp with Camera INFO
SketchUp Camera as Imported into KeyShot
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.

driven

have you contacted Luxion support?
which of the 2 versions of the plugin is failing?

I haven't used Ketyshot for years, but it seems like the export may need updating for v2015...
john

driven

can you post this file
/Library/Application Support/KeyShot5/keyshot5.xml

i can check if the problem is coming from SU...

chippwalters

I can, but first tell me what is that file for? What exactly does it do? I may need to get it from my office computer unless it's okay to reproduce on my home computer.

chippwalters

Here's the file.
https://dl.dropboxusercontent.com/u/3788438/3D/keyshot5.xml

driven

@chippwalters said:

I can, but first tell me what is that file for? What exactly does it do? ...

I finally went to bed last night and missed this post,
it's just a setting file, easier than asking you to list all the possible setting...
unfortunately it doesn't tell me anything decisive about the fov...
you can remove it from the post now...
I'll have another look at their plugin...
no promises...
john

driven

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

If what you're asking is if I used the Advanced Camera, I believe so. I did actually use an AC for export as shown in the first image above (see the camera settings values in dot 1).

That said, I had installed some AC plugin and I have now about 20 different camera 'types' I can set. I suppose this does not matter. I am setting the SU window to 1600 x 900 pixels and the Keyshot is set to 1280 x 720 which is the same 16:9 aspect ratio. Let me know if there's anything I need to send or do, or if I'm miscommunicating anything.

I can try modifying the plugin code.

Thanks for your help.

driven

@chippwalters said:

If what you're asking is if I used the Advanced Camera, I believe so. I did actually use an AC for export as shown in the first image above (see the camera settings values in dot 1).

the setting AC tools prints on the screen are rubbish, it could easily supply better info about the 'screen'...

@unknownuser said:

...I am setting the SU window to 1600 x 900 pixels

are you using my plugin for that?

@unknownuser said:

and the Keyshot is set to 1280 x 720 which is the same 16:9 aspect ratio...

is that not auto from the SU size?

chippwalters

Yep, using your fine plugin to set the screen window resolution. Thanks!

I don't know, maybe the 1280x720 is set from the plugin. I typically use the same fixed size as my default, but I can certainly check and let you know.

driven

can you try a simple cube in a different sized SU window and see if KS adjusts...

chippwalters

Nope, KeyShot does not adjust. It always defaults to the last screen setting which KS was left in.
Interesingly, the CAMERA shows up as an object in KeyShot. Here's a possible workaround-- though certainly NOT perfect.

See below:

Camera Object in KS
Camera Object shown in SU Camera view (inside of cube) showing the 'bounds' of the camera cone.
Camera Object shown in SU showing 'bounds' of camera cone
First change FOV so that the edges of the 'bounds' extend to the horizontal borders of the KS camera window.
Set aspect ratio so that it matches the SU aspect ratio..

Still need to test:
Different FOVs and Different SU aspect ratio other than square.

driven

your image are to small for me to read, when I enlarge them the text is to distorted...

however, you want to see if this works, without the workaround?
download this
in Ruby Console

load ~/Downloads/keyShotExporter.rb

then test a correctly size window export...

may work...

chippwalters

I'll take a look at the plugin and let you know.

Even though the image is small, I believe the details aren't important other than the overall notion that one can manually adjust the FOV using the imported SU Camera Geometry Object to get 'close.'

Here's the same test using a different FOV and aspect ratio (green is because it's using your plugin and is perfect 16:9).

Green 16:9 Aspect Ratio with different FOV than first test.
Imported into Keyshot. Border is indicated.
Adjust Field of View to match border then render. Looks very close.

chippwalters

@driven said:

however, you want to see if this works, without the workaround?
[attachment=0:3036vr1q]keyShotExporter.rb[/attachment:3036vr1q]
in Ruby Console

load ~/Downloads/keyShotExporter.rb

then test a correctly size window export...

may work...

Thanks for the help! When I run it I get this:

> load ~/Downloads/keyShotExporter.rb
Error; #<SyntaxError; <main>; unknown regexp options - kyShtEprtr>
SketchUp;1;in `eval'

chippwalters

Yes, I contacted them. They don't really have an answer. They say it works with SU15 but the camera transfer doesn't work right. I was hoping to try and figure out a manual way to go from one setting to the other. I know it's possible to do it manually, I just need to find the right 'formula' and while I posted this same on their forum (and support ticket), I doubt there's much if any answer there.

driven

I forgot the quotes ""

load  "~/Downloads/keyShotExporter.rb"

chippwalters

Sorry to be a pain. But now, when I copy/paste it in I receive:

> load  "~/Downloads/keyShotExporter.rb"
/Users/chippwalters/Downloads/keyShotExporter.rb;35; warning; already initialized constant KeyShot5;;Set
/Users/chippwalters/Library/Application Support/SketchUp 2015/SketchUp/Plugins/luxion_keyshot5/keyShotExporter.rb;35; warning; previous definition of Set was here
/Users/chippwalters/Downloads/keyShotExporter.rb;316; warning; already initialized constant KeyShot5;;TEXTURE_PATH
/Users/chippwalters/Library/Application Support/SketchUp 2015/SketchUp/Plugins/luxion_keyshot5/keyShotExporter.rb;309; warning; previous definition of TEXTURE_PATH was here
/Users/chippwalters/Downloads/keyShotExporter.rb;319; warning; already initialized constant KeyShot5;;VERSION
/Users/chippwalters/Library/Application Support/SketchUp 2015/SketchUp/Plugins/luxion_keyshot5/keyShotExporter.rb;312; warning; previous definition of VERSION was here
true

Not sure what to do...

slbaumgartner

Those warnings occur when you reload a Ruby that defines constants in its code. They won't happen if the code is written to allow for this possibility. However, in most cases the warnings have no effect and can safely be ignored. The final line saying "true" is your indicator that the load succeeded.

chippwalters

So then, what do I do next? Use the Keyshot plugin button to export the file? Will it use your script or it's script?