# Forum

### Author Topic: Define local coordinate system using planes  (Read 1293 times)

#### Fergy

• Newbie
• Posts: 5
##### Define local coordinate system using planes
« on: January 27, 2022, 11:54:20 AM »
Hi!

I've been trying to find a way to define a local coordinate system with X and Y defined by circular targets and imported reference coordinates (with inaccurate Z definitions), and correcting Z by using coded targets to define a Z plane. It would be extremely useful to be able to define X and Y using planes as well, as it would essentially be the same function.

I have used a CSV to define X0,Y0 and Z0 with high accuracy values and defining the other coordinate values with extremely low accuracy. The issue is that I get a 45deg rotation around Z, and error of around 1m for the markers. Any ideas?

#### Alexey Pasumansky

• Agisoft Technical Support
• Hero Member
• Posts: 14891
##### Re: Define local coordinate system using planes
« Reply #1 on: January 27, 2022, 06:26:28 PM »
Hello Fergy,

Which information do you have on input?
Coordinates of the origina point (X0, Y0, Z0), pairs of markers defining axes direction or marker triplets defining XY, XZ, YZ planes? How the scale is defined - do you have scale bars in the project?
Best regards,
Alexey Pasumansky,
Agisoft LLC

#### Fergy

• Newbie
• Posts: 5
##### Re: Define local coordinate system using planes
« Reply #2 on: January 31, 2022, 02:00:06 PM »
Hi Alexey,

I have marker triplets (rather, 4 markers per plane) to define each plane. Scale is defined by scale bars.

« Last Edit: February 02, 2022, 04:40:11 PM by Fergy »

#### Fergy

• Newbie
• Posts: 5
##### Re: Define local coordinate system using planes
« Reply #3 on: February 02, 2022, 04:40:20 PM »
For example, each plane would define the origin of a given axis (or some other value defined along that axis, perhaps 100mm as in Z, or in meters):

Target 1 - X0
Target 2 - X0
Target 3 - X0
Target 4 - X0
Target 5 - Y0
Target 6 - Y0
Target 7 - Y0
Target 8 - Y0
Target 9 - Z100
Target 10 - Z100
Target 11 - Z100
Target 12 - Z100

#### Fergy

• Newbie
• Posts: 5
##### Re: Define local coordinate system using planes
« Reply #4 on: February 10, 2022, 12:07:29 PM »
Any chance to have an answer if this is possible during the next few days? I have a project next week that I need to use this functionality with!