Line-of-Sight Tool?

[August]

Is there a "Line-of-Sight" tool in SU?

Several years ago I made my first (and only) Plug-in / Extension where you can click the tool anywhere in the scene and it creates a line exactly lined up with your line of sight at that point. So at first the line is invisible because you're looking right down its length. When you change the viewpoint, then you can see the line.

I remember seeing a reference a few years ago to a new tool in SU that does that kind of thing, so I'm reluctant to update the older Extension to work in the new SU with the new Extension policies if an equivalent already exists. But I've never found it.

Does a Line-of-Sight tool exist?

Can anyone shine a light on my vague memories?

Thanks,
August

[pbacot]

I think the Position Camera tool does the same thing if you set it to "0" height and drag it along the line, or am I wrong?

[August]

@pbacot said:

I think the Position Camera tool does the same thing if you set it to "0" height and drag it along the line, or am I wrong?

I don't use the Position Camera tool much but I don't think it's applicable. I'm not getting your meaning, for what I am seeking, of "drag it along the line." What line? Do you mean drag the camera, at zero height, along the ground. Not quite. My task is to create a new line, a 3D line, not one on the ground. Let me explain a little more.

My "Line-of-Sight" tool was initially primarily for photo matching, but I can imagine uses for planning movie shots as well, to plan what obscures what in a shot.

In use, you activate the tool and then click on a point in your view. Your click creates a line, but at first you see nothing because you have created a line relative to the current camera position and you are looking exactly down the length of the line. It's like shooting a laser beam out of the camera at any of the points in the scene that you are looking at. Shoot a bunch of them, while you are at it.

When you move the camera viewpoint with Orbit, then you can see the lines you created as all going through the original camera position and fanning out in 3D from there. Any particular line can let you identify everything that is along that Line-of-Sight that were all aligned in the original view.

My original intent was to use it for photo matching of things that don't have straight lines and flat planes, like trees and boulders on a building site, or even power poles, which are hugely difficult to place using Match Photo. With my tool, to position a tree trunk or power pole from photos, I shoot a line on either side of it in one view, switch to a different view and do that again, and again in a third view. Then looking from the top, I have six lines that show me where the tree looks to be in the photos and I can place the trunk in between them where it will align in all of the photos.

A few years ago a made a Ruby extension that does this, but it doesn't work with newer versions of SU. Someplace, in some thread, I got the idea that such a tool now exists in SU. I would like to know if that's true and what the tool is, before I put in the work of updating my my extension to work in the new SU.

[pbacot]

OK Sorry. I meant draw a line that represents the line of sight. It can be 3d up off the ground. Initiate the position camera tool (VCB: set the "height offset" to zero) and drag the cursor along that line in the direction of your object, release the mouse button. As described in your first post, the line would become invisible in the resulting view. I don't know what else your plugin does--it may have more to it.

Your use of Match Photo sounds pretty advanced. It would be great to see examples.

[pilou]

It's not specially for the Line of Sight but I believe that you can use it them also for that!

Radial Lines or Radial Lines fixed length by TIG

[Pixero]

Maybe this could help:
https://sketchucation.com/pluginstore?pln=jsCameraLine

[August]

Hi Pixero,

That tool appears to, as it says, draw a line from the camera to the "target", the center of the camera field.

My tool, when active, draws a line from the camera through the selected point in the frame. So from a single camera position, you can draw the rays that outline an object.

Would it be straightforward to modify your tool to do that?

Thanks,
August