Optitrak + Projector touch table/surface

Matlab scripts

Setting the optitrak plane in matlab

In place of the matlab code for reading in optitrak data, the following matlab function can be used to:

1. read in data sent from the optitrak system, and furthermore
2. set the table top plane, as understood by the Optitrak, into variables for reference in matlab, and
3. transform the native coordinate system of the optitrak (x z y) into another, possibly more familiar coordinate system (x y z).

This function should be called before opening a main window with psychtoolbox.

function [touch_plane_info, client] = opti_setup_touch_plane_srt

%This gives an error (freezes) if the NET assembly is already loaded. In %that case you need to quit Matlab and start over

if ~IsAssemblyAdded('NatNetML') Opti = NET.addAssembly('C:\Users\Jim Enns\Documents\MATLAB\NatNetSDK2.2\NatNetSDK\lib\NatNetML.dll'); end

client = NatNetML.NatNetClientML(1); %client.Initialize('142.103.0.167','142.103.0.167'); client.Initialize('142.103.251.175','142.103.251.175'); data = client.GetLastFrameOfData;

reply = 'N'; while ~strcmpi(reply,'Y')

answer = {}; while isempty(answer) prompt={'Pixel Coords: '}; name='Lower Left Corner'; numlines=[1,35]; %this width allows for title to be seen defaultanswer={'[0 768]'}; answer=inputdlg(prompt,name,numlines,defaultanswer);

%convert from string to number data for output variables if ~isempty(answer) OriginPixelCoords = str2num(answer{1}); end end

pDataDest = [data.OtherMarkers(1).x data.OtherMarkers(1).z data.OtherMarkers(1).y];

Question = {'LOWER LEFT pre coordinate transform:'... ... 'Marker 1: ' num2str(pDataDest(1:3))... ... 'Accept?'... }; ButtonName = questdlg(Question, 'Data Check', 'Yes', 'No', 'Quit', 'Yes');

switch ButtonName case 'Yes' orig_pos = pDataDest; reply = 'Y'; case 'No' reply = 'N'; case 'Quit' %quit opto too? %need to pass quit flag so this actually works? transform_info = []; clear all; close all; Screen('CloseAll'); disp('*** Exiting Program ***'); return end

end

%take a point on +ve x axis reply='N'; while ~strcmpi(reply,'Y')

answer = {}; while isempty(answer) prompt={'Pixel Coords: '}; name='Lower Right Corner'; numlines=[1,35]; %this width allows for title to be seen defaultanswer={'[1024 768]'}; answer=inputdlg(prompt,name,numlines,defaultanswer);

%convert from string to number data for output variables if ~isempty(answer) XAxisPixelCoords = str2num(answer{1}); end end

pDataDest = [data.OtherMarkers(1).x data.OtherMarkers(1).z data.OtherMarkers(1).y];

Question = {'LOWER RIGHT pre coordinate transform:'... ... 'Marker 1: ' num2str(pDataDest(1:3))... ... 'Accept?'... }; ButtonName = questdlg(Question, 'Data Check', 'Yes', 'No', 'Quit', 'Yes');

switch ButtonName case 'Yes' x_axis = pDataDest; reply = 'Y'; case 'No' reply = 'N'; case 'Quit' %quit opto too? %need to pass quit flag so this actually works? clear all; close all; Screen('CloseAll'); disp('*** Exiting Program ***'); return end end

% point on the xy plane reply='N'; while ~strcmpi(reply,'Y')

answer = {}; while isempty(answer) prompt={'Pixel Coords: '}; name='Upper Left Corner'; numlines=[1,35]; %this width allows for title to be seen defaultanswer={'[0 0]'}; answer=inputdlg(prompt,name,numlines,defaultanswer);

%convert from string to number data for output variables if ~isempty(answer) YAxisPixelCoords = str2num(answer{1}); end end

pDataDest = [data.OtherMarkers(1).x data.OtherMarkers(1).z data.OtherMarkers(1).y];

Question = {'UPPER LEFT pre coordinate transform:'... ... 'Marker 1: ' num2str(pDataDest(1:3))... ... 'Accept?'... }; ButtonName = questdlg(Question, 'Data Check', 'Yes', 'No', 'Quit', 'Yes');

switch ButtonName case 'Yes' y_axis = pDataDest; reply = 'Y'; case 'No' reply = 'N'; case 'Quit' %quit opto too? %need to pass quit flag so this actually works? clear all; close all; Screen('CloseAll'); disp('*** Exiting Program ***'); return end end

% finish the screen rect (event though this is redundant for establishing % the plane) reply='N'; while ~strcmpi(reply,'Y')

answer = {}; while isempty(answer) prompt={'Pixel Coords: '}; name='Upper Right Corner'; numlines=[1,35]; %this width allows for title to be seen defaultanswer={'[1024 0]'}; answer=inputdlg(prompt,name,numlines,defaultanswer);

%convert from string to number data for output variables if ~isempty(answer) OppCornerPixelCoords = str2num(answer{1}); end end

pDataDest = [data.OtherMarkers(1).x data.OtherMarkers(1).z data.OtherMarkers(1).y];

Question = {'UPPER RIGHT pre coordinate transform:'... ... 'Marker 1: ' num2str(pDataDest(1:3))... ... 'Accept?'... }; ButtonName = questdlg(Question, 'Data Check', 'Yes', 'No', 'Quit', 'Yes');

switch ButtonName case 'Yes' opp_corner = pDataDest; reply = 'Y'; case 'No' reply = 'N'; case 'Quit' %quit opto too? %need to pass quit flag so this actually works? clear all; close all; Screen('CloseAll'); disp('*** Exiting Program ***'); return end end

%Create the Coordinate Systesm [T_opto_plane,T_plane_opto]=MakeCoordSystem(orig_pos,x_axis,y_axis);

%Display the new transformed coordinate system disp('Points in Local Coordinate System are:') [new_orig]=transform4(T_opto_plane, orig_pos) [new_x_axis]=transform4(T_opto_plane, x_axis) [new_y_axis]=transform4(T_opto_plane, y_axis) [new_opp_corner]=transform4(T_opto_plane, opp_corner)

touch_plane_info.T_opto_plane = double(T_opto_plane); touch_plane_info.T_plane_opto = double(T_plane_opto); touch_plane_info.opto_rect = double([new_orig; new_x_axis; new_y_axis; new_opp_corner]); touch_plane_info.pixel_rect = double([OriginPixelCoords; XAxisPixelCoords; YAxisPixelCoords; OppCornerPixelCoords]); touch_plane_info.old_opto_rect = double([orig_pos; x_axis; y_axis; opp_corner]);

%calculate the pixel to opto conversion mm1 = double((new_x_axis(1) - new_orig(1))/(XAxisPixelCoords(1) - OriginPixelCoords(1)) * 1000); mm2 = double((new_opp_corner(1) - new_y_axis(1))/(OppCornerPixelCoords(1) - YAxisPixelCoords(1)) * 1000); mm3 = double(-(new_orig(2) - new_y_axis(2))/(OriginPixelCoords(2) - YAxisPixelCoords(2)) * 1000); mm4 = double(-(new_x_axis(2) - new_opp_corner(2))/(XAxisPixelCoords(2) - OppCornerPixelCoords(2)) * 1000); touch_plane_info.mmPerPixel = mean ([mm1 mm2 mm3 mm4]);