SketchUp and KeyShot FOV and Focal Length don't match

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?

driven

steve beat me to it but hi ho...
there just warnings, because we overwrite the existing one for the SU session...
the advantage of testing this way is it's immediate and if it doesn't work you just trash it...
the old one will load again after a restart...

if it does work, you can move it to the folder and rename the old one or trash it...

driven

@chippwalters said:

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?

it will use the last loaded script, i.e. my version...

chippwalters

Thanks.

I did what you said, but the results weren't what was expected:

ORIGINAL in SU (Focal Lenght 42mm, FOV 46.8 degrees)
Using your plugin code. Note the FOV is different, but still not correct.
ORIGINAL KS Plugin. Note the FOV is also different.

driven

you want post the skp [or PM...]

chippwalters

Here's the SKP
https://dl.dropboxusercontent.com/u/3788438/3D/test.skp

driven

btw, so you know...

the only thing I change was a 'back up' for a SU shortfall

 if cam_aspect == 0.0
        cam_aspect = width/height.to_f.round(3)
      end

I you don't have a Advanced camera set, SU sets the aspect ratio to 0.0, which is crazy...
this bit of code just tell KS to use 16:9 in that circumstance...

I'll have a look at your skp...

chippwalters

@driven said:

btw, so you know...

the only thing I change was a 'back up' for a SU shortfall

 if cam_aspect == 0.0
>         cam_aspect = width/height.to_f.round(3)
>       end

I you don't have a Advanced camera set, SU sets the aspect ratio to 0.0, which is crazy...
this bit of code just tell KS to use 16:9 in that circumstance...

I'll have a look at your skp...

Thanks again for your generous help.

I did look at your Ruby and saw that, and was wondering if there was anything else. I've written some Python scripts for Vue-Infinite, but don't know much about SU's api-- other than other plugins have figured this out-- and KS hasn't. I believe they first mentioned to me SU didn't have the correct api hooks to get an accurate camera from. That's when I mentioned all the other renderers have figured it out. They said they would take a look at it. Last time they said they'd work on the SU plugin it took them 2 years.

Too bad Thea and Vray are so damn slow compared to Keyshot. Of course, they both can do a lot more too!

Fwiw, here's an interior shot modeled in SU, and rendered in KS @ 1920x1080. Took a bit under 3 hours on my 2013 i7 iMac. Anyone think Thea can do that? If so, I have a license and can try. My early tests told me no, but then I'm not an accomplished Thea user.

driven

that looks very well accomplished to me...

I think KS may ignore the 0.0, even though they extract it...
heres some code that I've been fiddling with to try and work out the variance...

      model = Sketchup.active_model
      camera = model.active_view.camera
      position = camera.eye.to_a
      direction = camera.eye.vector_to(camera.target)
      up = camera.up
      fov = camera.fov
      aspect_ratio = camera.aspect_ratio
      width = model.active_view.vpwidth
      height = model.active_view.vpheight
    
     p [ position, direction.to_a, camera.up.to_a, fov, aspect_ratio, width, height]
     

model = Sketchup.active_model
view = model.active_view
target = camera.target
vector = target - position

if vector.x>0
  if vector.y>0
    az = Geom;;Vector3d.new(0,1,0).angle_between(vector).radians
  else
    az = Geom;;Vector3d.new(1,0,0).angle_between(vector).radians+Math;;PI/2
  end
else
  if vector.y<0
    az = Geom;;Vector3d.new(0,-1,0).angle_between(vector).radians+Math;;PI
  else
    az = Geom;;Vector3d.new(-1,0,0).angle_between(vector).radians+(3*Math;;PI/2)
  end
end

the first one is just the same as KS pulls out
the second bit is trying to see how they arrive at the azimuth...
I remember reading some where that SU reads from the camera 'film' plane and you need to subtract the length to the lens 'plane', or similar... [I can't find the link]
the API has to much misinformation about all of this...

john

chippwalters

Thanks for you help. I'll test your new code tomorrow when I get a moment.

The workaround I found seems to be doing the trick: Here's a model I built tonight and used a SU wireframe overlaid on top (autonomous mobile office meeting room for an article) and it seems to work pretty well . FWIW, the model is not complete...just WIP).