---
title: "Set the floor plane"
canonical: "https://help.vicon.com/space/Evoke18/397969050/Set%20the%20floor%20plane"
format: markdown
---
The final stage in calibrating your Vicon cameras is to set the floor plane, using objects in the volume to automatically define it. 

The position of the virtual floor that is derived during setting the origin is extrapolated from the position of the wand in relation to floor of the volume. As the wand is a small object compared with the size of the volume, any slight discrepancy from the wand being level has a large effect over the rest of the volume when you set the origin. To account for any discrepancy, you set a floor plane, which takes a much larger area into account, so that the virtual floor lines up correctly with the actual floor plane. 

**To set the floor plane:**

1. Ensure you have completed the rest of the camera calibration procedure and set the origin (see [Set the volume origin](https://vicon-help.atlassian.net/wiki/spaces/Evoke18/pages/397969019)).
2. Turn off the wand or remove it from the volume.
3. Place a minimum of four Pulsar clusters across the volume floor.  
(If you need to change the default 7 mm floor plane setting (the setting for Pulsars is normally 14 mm), see [Adjust the Set Floor Plane settings](#AdjustFPSettings).)
4. In the** Camera Calibration** panel, go to the **Volume Setup** section, display Advanced Parameters > Macro (inline-media-image)

 and in the **Set Floor Plane** section, click **Start Set Floor Plane**.  
The button displays **Set Floor Plane**.
5. After a few seconds, click **Set Floor Plane**.
  In the **3D View**, ensure that in the **View Filters** options, **Cameras** is selected.
  In the **Perspective** view, notice that the cameras shift as a group slightly along one or more rotation axes to better reflect an average of the markers scattered across the floor, taking into account any offsets that you specified.
  :check_mark: **Tip**: To more accurately visualize the size of your volume in Evoke, you can change the size and shape of the floor grid. To do this, in the **Camera Calibration** panel, go to the **Volume Setup** section, ensure the Advanced options > Macro (inline-media-image)

 are displayed, and in the ** Set Floor Grid ** section, change the values (in mm) to produce the required result.

> Macro (scroll-pagebreak)

#### > Macro (anchor)

Adjust the Set Floor Plane settings

When setting the floor plane, Evoke uses the center of all markers it has identified as being in the same plane. As the center of the marker is actually above the ground, you will need to specify an offset or else your floor plane (and Global Origin) may be higher than desired. To set the floor plane accurately, in the **Camera Calibration** panel, go to the **Volume Setup** section, ensure the Advanced options > Macro (inline-media-image)

 are displayed, and in the **Set Floor Plane** section, change the **Height offset** to an appropriate value.

The **Height offset** is the amount (in mm) by which to adjust the floor plane (the default is 7 mm). Because Evoke finds the centers of the Pulsars, set a **Height offset** that accounts for the size of the Pulsars (normally 14 mm). If the Pulsars include a base, take this into account in your calculations.

> ![SetFloorPlane.png](media://0467c8ea-61e6-4f37-9b4c-3effaddb09eb)

To more accurately visualize the dimensions of your volume, change the size and shape of the floor grid. For more information, see [Set the volume origin](https://vicon-help.atlassian.net/wiki/spaces/Evoke18/pages/397969072).