Distace from Camera to object in drawing.

Al Hart · 2 Feb 2010, 23:12

I would like to be able to move the mouse around on a drawing and view the distance from the camera to the object near the mouse.

I know I could write a tool to do this, but there is probably one out there already. Can someone point me in the right direction?

Gaieus · 3 Feb 2010, 00:47

Hi Al,

Here is one - by Rick - and it's free!
http://www.smustard.com/script/CameraDistance

Jim · 3 Feb 2010, 00:51

Maybe Fullmer (or you) can add this to his Onscreen plugin:

http://forums.sketchucation.com/viewtopic.php?f=323&t=16837

Al Hart · 3 Feb 2010, 02:19

@gaieus said:

Hi Al,

Here is one - by Rick - and it's free!
http://www.smustard.com/script/CameraDistance

Thanks, I'll give it a look.

Chris Fullmer · 3 Feb 2010, 05:07

@jim said:

Maybe Fullmer (or you) can add this to his Onscreen plugin:

http://forums.sketchucation.com/viewtopic.php?f=323&t=16837

Oh Jim, that is an old plugin. I should look at it again. i can't believe it works at all!

Chris

Jim · 3 Feb 2010, 05:16

Oh sorry - I know how you feel!

Al Hart · 3 Feb 2010, 05:30

@gaieus said:

Hi Al,

Here is one - by Rick - and it's free!
http://www.smustard.com/script/CameraDistance

This one returns to distance from the camera t the eye.

I would like to have a tool which lets you determine the distance from the camera to arbitrary objects in the drawing. I want to use it to set Focal Lengths for Depth of Field calculations.

This is not a good example, because the eye may be in the same place as the center of focus, but if the eye were raised up a bit, then it would probably be way behind the desired focal point.

thomthom · 3 Feb 2010, 07:23

Ah - yes. That would be a good tool. And for my use, since I'd use V-Ray I'd want it to display the distance in inches as well as model units.

Not sure if there's a tool like that out there though.

TIG · 3 Feb 2010, 12:23

Assuming that you have something selected then

model=Sketchup.active_model
eye=model.active_view.camera.eye
ss=model.selection[0]
distance=eye.distance(ss.bounds.center)

returns the distance from the camera's 'eye' to the 'center' of the selection's bounding-box...
You can of course improve this - another way to get the distance to the 'face' of a selection would be to get the vector between the 'eye' and the 'center' and then do a 'raytest' to find the first point hit and get that distance...

model=Sketchup.active_model
eye=model.active_view.camera.eye
ss=model.selection[0]
distance=(model.raytest[eye, eye.vector_to(ss.bounds.center)])[0].distance(eye)

This then returns the 'distance'...
You can improve it further by testing if the second item in the returned raytest array contains the selected object and if not redo the raytest from the first item [point] in its array along the same vector...

model=Sketchup.active_model
eye=model.active_view.camera.eye
ss=model.selection[0]
vector=eye.vector_to(ss.bounds.center)
rayt=model.raytest[eye,vector]
pt=rayt[0]
while not rayt[1].include?(ss)
  rayt=model.raytest[pt,vector]
  pt=rayt[0]
end#while
pt=rayt[0]
distance=eye.distance(pt)

Hope this helps...

Al Hart · 3 Feb 2010, 16:39

I took the utilitiestools.rb script in SketchUp, which displays an X,Y location as you move the mouse and changed it to display the distance from the camera instead.

The heart of the change is this routine to display the camera distance:


	# get camera distance from the eye to a point at (x,y,0)
	def get_distance(target)
		model = Sketchup.active_model
		eye = model.active_view.camera.eye
		distance = eye.distance(target)
		# display in drawing units and inches
		slength = Sketchup.format_length(distance) + sprintf(" (%g\")", distance)
		return slength
	end#def

Try the attached script: get_camera_distance.rb

[Edit: I uploaded a new version of get_camera_distance.rb]

get_camera_distance.rb

TIG · 3 Feb 2010, 17:01

But that measures the eye to target distance...
You want the eye to object distance ?
The object might be between the target and the eye positions !
See my example on how to use the eye>>>target vector and raytest from the eye along that vector for objects in between... perhaps using a selected object as the source [it needs work as it was only a first draft... but selecting a group/instance between the eye and target will give the distance to it ?]

Al Hart · 3 Feb 2010, 17:02

There was a bug in get_camera_distance.rb.

I uploaded a new version.

(One person had downloaded it already - sorry - please get a new version)

Al Hart · 3 Feb 2010, 17:26

@tig said:

But that measures the eye to target distance...
You want the eye to object distance ?
The object might be between the target and the eye positions !
See my example on how to use the eye>>>target vector and raytest from the eye along that vector for objects in between... perhaps using a selected object as the source [it needs work as it was only a first draft... but selecting a group/instance between the eye and target will give the distance to it ?]

I call get_distance(target) with the point from OnMouseMove() after calling pick(x,y) - not the target of the camera view.

I think it is working properly.

Here is a rendering after selecting the end of the cylinder as the target point and setting the Depth of Field to be very blurry (3.0).

TIG · 3 Feb 2010, 19:57

I apologize...
I hadn't read your script fully - your target isn't camera.target - you have a good idea - it works fine...

Bertier · 15 Jul 2011, 08:23

hello

could that plugin be used to create motion blur in an animation ?

thank you.

mpowell1234567890 · 9 Aug 2011, 20:21

Cool, thanks. Love it when I can know how far away something is in a model.

@al hart said:

I took the utilitiestools.rb script in SketchUp, which displays an X,Y location as you move the mouse and changed it to display the distance from the camera instead.

[attachment=1:2q0r3qa8]get_focal_length.jpg[/attachment:2q0r3qa8]

The heart of the change is this routine to display the camera distance:


> 	# get camera distance from the eye to a point at (x,y,0)
> 	def get_distance(target)
> 		model = Sketchup.active_model
> 		eye = model.active_view.camera.eye
> 		distance = eye.distance(target)
> 		# display in drawing units and inches
> 		slength = Sketchup.format_length(distance) + sprintf(" (%g\")", distance)
> 		return slength
> 	end#def
>

Try the attached script: get_camera_distance.rb

[Edit: I uploaded a new version of get_camera_distance.rb]

pibuz · 12 Feb 2012, 15:10

That is a lovely script, but it seems I'm not able to load it..
How can I do that?

Thanks a lot Al!

**EDIT: ok, I moved the original utilities rb to another folder and renamed your script "utilitiestools.rb", and it works: now I can get camera distance
Is there a less homemade or brute method? Thanks again?

Dan Rathbun · 12 Feb 2012, 17:15

Renaming files is dangerous.

Make a subfolder of Plugins dir, named: !_autoload

" %(#8000BF)[Plugins/!_autoload]"

Then get my !autoload script here, and put it in Plugins folder.

After.. you can put little scripts that you wish to autoload in the " %(#8000BF)[Plugins/!_autoload]" folder.

angeli7on · 4 Jan 2013, 10:37

Hi, I got confused about this.
I try using get_camera_distance but the result aren't DOF
am I missing something ?

here I attach my screen shot
if too small I also upload here:
http://imageshack.us/f/254/bingungdof2.jpg

please advice, thanks alot.

TIG · 4 Jan 2013, 11:07

But the distance given by the tool is 703" - not '10' units in the Camera DOF dialog ?
Try using the real equivalent distance [in the correct units for that dialog] to see what happens.
The distance returned by the tool is the distance from the camera 'eye' up to the picked point - in your screenshot it's given in 'inches'...