How to update the 'Buildings' parameter in 'siteviewer' without recreate a new 'siteviewer'?

I get the raytrace results for multiple users under the varying environment. I could vary the propery (riverTbl.MinHeight in the following code) that I want to vary, but the 'raytrace' need the 'Map' input is a 'viewer', and 'viewer.Buildings' proporty is read-only (https://au.mathworks.com/help/antenna/ref/siteviewer.html?s_tid=srchtitle_support_results_1_siteviewer#d126e157388).

So my question is how to update the 'building' parameter in 'siteviewer' without recreate a new 'siteviewer'?

part of my code following digital twin example https://au.mathworks.com/help/5g/ug/analyze-sinr-in-6g-fr3-network-using-digital-twin.html

pm = propagationModel("raytracing",MaxNumReflections=maxNumReflections, ...
    MaxNumDiffractions=maxNumDiffractions);


parfor k = 1:numel(waterLevels)
    fprintf("simulated water level is %f", waterLevels(k));
    rx = rxsite(Latitude=-33.821949,Longitude=151.094490,AntennaAngle=[0; 40], AntennaHeight=5);
    nUEs = length(rx);
    % Assign arrays to each rxsite
    for n = 1:nUEs
        rx(n).Antenna = phased.URA(Size=rxArraySize,ElementSpacing=0.5*lambda);
    end

    % 1) Make a one-row table with the same structure as buildingsTbl
    riverTbl = buildingsTbl(1,:);   % copy structure & variable types
    % 2) Overwrite fields for the river object
    riverTbl.Shape      = riverShape;          % horizontal water polygon
    riverTbl.Name       = "River";  % optional
    riverTbl.Material   = "water";             % use a material you define in dict
    riverTbl.Color      = "#89CFF0";           % any color you like
    riverTbl.Type       = buildingsTbl.Type(2);           % just a label
    
    % Heights: treat water as a shallow horizontal slab
    riverTbl.MinHeight  = waterLevels(k);          % water surface height
    riverTbl.MaxHeight  = waterLevels(k);          % same => effectively a plane
    
    % IDs: just give some unique dummy values so they don't collide
    riverTbl.BuildingID = "Parramatta River";
    riverTbl.PartID     = 0;
    
    % Centroid: optional – if you need it, you can approximate by bounding box
    % (Site Viewer/ray tracer does *not* require Centroid)
    try
        gt = table(riverShape,'VariableNames',{'Shape'});
        t  = geotable2table(gt,"Latitude","Longitude");  % Mapping Toolbox
        latc = mean(t.Latitude,"omitnan");
        lonc = mean(t.Longitude,"omitnan");
        riverTbl.Centroid = geopointshape(latc,lonc);
    catch
        % Fallback: reuse an existing centroid, not critical for ray tracing
        riverTbl.Centroid = buildingsTbl.Centroid(1);
    end

    riverTbl.Shape = geoclip(riverTbl.Shape, AOI);
    riverTbl = riverTbl(riverTbl.Shape.NumRegions > 0, :);
    
    % 3) Combine buildings and river into one scene table
    sceneTbl = [buildingsTbl; riverTbl];

    viewer = siteviewer(Buildings=sceneTbl, Terrain="none", Basemap="grayland", Hidden=true);
    rays = raytrace(tx,rx,pm, Map=viewer);
    carrier = pre6GCarrierConfig(NSizeGrid=NRB);

    % Calculate channel matrices using SVD
    H = calculateChannelMatrix(carrier,tx,rx,rays);
    
    % Calculate precoding (digital beamforming) and combining weights for all gNB to UE links
    [Wrx,S,Wtx] = pagesvd(H);

    % UE received signal power (dBm)
    ueSignalPowerdBm = calculateSignalPower(tx,rx,rays,Wtx,Wrx);
    
    % UE received signal power (W)
    ueSignalPowerW = dBm2W(ueSignalPowerdBm);
    rxPowerByLevel{k} = ueSignalPowerdBm;

    close(viewer);
end

Answer 1

[Aditya]

Hi Evelyn,

You cannot update the buildings in a siteviewer after creation—the Buildings property is read-only and there’s no documented way to update it in-place. You must create a new siteviewer each time you change the environment.

• The siteviewer object’s Buildings property is read-only (see documentation).
• There are no public methods to update or clear buildings in an existing siteviewer.
• The typical workflow (as in your code) is to create a new siteviewer for each environmental change, run your simulation, then close it.

You can minimize overhead by setting Hidden=true so the GUI does not render.

[evelyn]

thank you for your reply.