Problems with nDisplay with 2 beamer on a cylindrical wall

Hi all,

we’re nearly there, but are struggling with Unreals nDisplay configuration file.

Our Setup is:

  • 2 beamer onto a cylindrical wall (left beamer on left side, right one on right side)
  • we use Scalable’s display manager to compute the projection correction file
  • we want to use perspective mesh as we desire a flight-sim like effect
  • we used the “cylinder screen” in the Display manager for our perspective setup
  • we like to use the .pol file as mentioned in the nDisplay docs
  • we use both 4k beamers as one display (combined per nvidia Setup) with a resolution of 4320x4096

Our config file is:

[info] version="23"

[cluster_node] id="node_main" addr="" window="wnd_main" master="true" sound="false"
[window] id="wnd_main" WinX=0 WinY=0 fullscreen="false" ResX=4320 ResY=4096 viewports="vp_main"
[viewport] id="vp_main" x=0 y=0 width=4320 height=4096 projection="proj_main"
[projection] id="proj_main" type="easyblend" file="C:	est\ScalableData.pol"   origin=eye_level scale=1
[camera] id="camera_static" loc="X=0,Y=0,Z=0" rot="P=0,Y=0,R=0" eye_swap="false"  force_offset="0"

[scene_node] id="origin"   loc="X=0,Y=0,Z=0"      rot="P=0,Y=0,R=0"
[scene_node] id="eye_level"    loc="X=0,Y=0,Z=-19"    rot="P=0,Y=0,R=0"   parent="origin"

The output doesn’t look perspective corrected to us and is quite blurry (like rendering low-res onto a texture).

We are especially unsure on how to use the “scale” Parameter in the “[projection]” line of the config file. Unfortunately the documentation there is very thin.

Does anyone have any experience or further Information on how to use scaleable in combination with Unreals nDisplay?

Or if we are on the right path here or if we need .pfm files or else for our intended use?

Can anyone assure what coordinate system is used in the config file? Same as Unreal’s?

Sorry, lot of questions :slight_smile:
Any hints are appreciated.

Thanks in Advance,

Best Regard,


Hi Bodo,

The most likely your issue is the scale parameter. Depending on the units used in Scalable software during calibration, a corresponding scale value must be set. Here are few examples:
Calibration in meters -> scale=1
Calibration in millimeters -> scale=0.001
Calibration in inches -> scale=0.0254

**Can anyone assure what coordinate system is used in the config file? Same as Unreal’s? **
nDisplay config file uses the same coordinate system as Unreal. The only difference is the offsets are in meters. Please note, this doesn’t relate to calibrationunits of Scalable .ol/.pol data. And yes, continue using .pol.

I would be able to give some more help if you share your config file and calibration data (somewhere in C:\Program Files\Scalable…\LocalCalibrationData). If you don’t mind, please share it with google drive or some other way to [EMAIL=“”]