Moving camera sensor

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luka
Posts: 7
Joined: Thu Jan 07, 2021 10:20 am

Moving camera sensor

Post by luka »

Hi!

I have got a question regarding a camera sensor I created. In the added picture you can see the created camera sensor.
The settings of this camera are:

Centre X (right) Y (up) Z(inv. View dir.)
53.775002 0 50 0
81.472000 0 0 50
51.066486 20 0 0

With an vert f.o.v. of 45 degrees.

I want to move (or place another camera sensor) the camera sensor to the left, so that another part of the street falls into the camera view, as I need camera views allaround from this centre. However I can't make it work to move the camera sensor, it only moves in wrong directions like up or down. What do I need to adjust so that the camera sensor solely moves horizontally to the left?

Hope you can help!

Luka
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Schermafbeelding 2021-01-07 112540.png (17.2 KiB) Viewed 4322 times
daniel
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Re: Moving camera sensor

Post by daniel »

I would simply change the center? (and I don't know the coordinate system of the cloud but I would assume you'll have to change X or Y)

Mind also that the X, Y and Z directions of the camera should ideally be unit vectors (you can replace 20 or 50 by 1).
Daniel, CloudCompare admin
luka
Posts: 7
Joined: Thu Jan 07, 2021 10:20 am

Re: Moving camera sensor

Post by luka »

Thanks for your answer.

The point is that I'd like complete camera views from the same centre (what is all visible from 1 point), or is that not possible?
daniel
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Location: Grenoble, France
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Re: Moving camera sensor

Post by daniel »

The 'center' is the optical center of the camera. Not the target point. If you want to move the camera while keeping the same target point, you'll have to update its orientation accordingly.
Daniel, CloudCompare admin
luka
Posts: 7
Joined: Thu Jan 07, 2021 10:20 am

Re: Moving camera sensor

Post by luka »

Yes I get that the center is the optical center, but when changing the X and/or Y coordinates of this center the camera is indeed replaced, but the orientation of the camera stays the same, and that is the factor which I want to change. I would like a 360 view from a certain target point, but when changing the X (right) or Y (up) only the size of the camera view changes but not the orientation/angle. Also when changing for instance the vert f.o.v. the camera sensor does not point towards another direction.
WargodHernandez
Posts: 187
Joined: Tue Mar 05, 2019 3:59 pm

Re: Moving camera sensor

Post by WargodHernandez »

The easiest way to do what I think you are wanting is to create multiple sensors with your initial conditions and the rotate the copies around an axis of the orig sensor, I did that with two sensor objects to show what I mean

Image

Here is what you will want to transform the follow on sensors by
1.000000000000 0.000000000000 0.000000000000 0.000000000000
0.000000000000 0.898578882217 -0.438812077045 30.671573638916
0.000000000000 0.438812077045 0.898578882217 -30.571676254272
0.000000000000 0.000000000000 0.000000000000 1.000000000000

if you want them to rotate around the other axis like this
Image

then use the following matrix to transform by
0.000000000000 50.000000000000 0.000000000000 53.775001525879
-8.776241302490 0.000000000000 44.928943634033 81.472000122070
17.971576690674 0.000000000000 21.940603256226 51.066490173340
0.000000000000 0.000000000000 0.000000000000 1.000000000000
luka
Posts: 7
Joined: Thu Jan 07, 2021 10:20 am

Re: Moving camera sensor

Post by luka »

Thank you so much @WargodHernandez , this is indeed exactly what I meant! Especially the first picture, that is the axis I want it to rotate on.

From your piece of text however it is not clear what numbers are the X, Y or Z coordiantes. Could you specify this? Or share a screenshot of the box with sensor parameters in cloudcompare, then I get what input coordinates needs to be changed.

My current sensor, of which I want to rotate from has the following scheme:

0.000000 50.000000 0.000000 -45.984001
0.000000 0.000000 50.000000 -18.527000
20.000000 0.000000 0.000000 47.273487
0.000000 0.000000 0.000000 1.000000
WargodHernandez
Posts: 187
Joined: Tue Mar 05, 2019 3:59 pm

Re: Moving camera sensor

Post by WargodHernandez »

Apply the following transform:

0.707137703896 -0.707069396973 -0.003010381712 -26.368270874023
0.707069396973 0.707106769085 0.007268088404 26.600149154663
-0.003010381712 -0.007268088404 0.999969005585 -0.271043986082
0.000000000000 0.000000000000 0.000000000000 1.000000000000
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