read

Since R2025a

Create a camera in the 3D environment using the sim3d.sensors.Camera object. You can capture images of the 3D environment and display them in MATLAB®. Use the read function to extract image data from the 3D environment.

Create a 3D environment and set up communication with the Unreal Engine simulation environment using the output function OutputImpl and the update function UpdateImpl. The sim3d.World object can send and receive data about the 3D environment to and from the Unreal Engine at each simulation step using output and update functions, respectively. Before the Unreal Engine simulates, MATLAB calls the output function and sends data to the Unreal Engine. Then, the Unreal Engine executes at each time step and sends data to MATLAB in the update function. You can use the update function to read this data or change values after each simulation step.

world = sim3d.World(Output=@outputImpl,Update=@updateImpl);

Create a box actor in the 3D environment using the sim3d.Actor object and add the box to the world.

cube = sim3d.Actor( ...
        ActorName="Cube", ...
        Mobility=sim3d.utils.MobilityTypes.Movable);
createShape(cube,"box");
add(world,cube);

Create a camera object using the sim3d.sensors.Camera object and set the location of the camera using the Translation property. Add the camera to the world.

camera = sim3d.sensors.Camera( ...
        ActorName="Camera");
camera.Translation = [-3 0 0];
add(world,camera);

Run the co-simulation.

sampletime = 1/60;
stoptime = 2;
run(world,sampletime,stoptime);

function outputImpl(world)
    world.Actors.Cube.Rotation(3) = world.Actors.Cube.Rotation(3) ...
    + 0.01; 
end

function updateImpl(world)
    sceneImage = read(world.Actors.Camera);
    image(sceneImage);
end

Since R2025a

Generate depth and semantic data for the 3D environment. Create a camera in the 3D environment using the sim3d.sensors.Camera object. You can capture images, generate depth and semantic data for the 3D environment and, display the images in MATLAB®. Use the read function to generate the depth and semantic data for the 3D environment.

Create figure windows and specify the name using the figure function.

imageFigure = figure(Name="Image");
depthFigure = figure(Name="Depth");
semanticFigure = figure(Name="Semantic");

Create a 3D environment using the sim3d.World object. Set up communication with the Unreal Engine simulation environment using the output function OutputImpl and the update function UpdateImpl. An anonymous function is defined using @(world), where world is the current state of the sim3d.World object during each simulation step. This function calls the UpdateImpl function, which takes world and the figure window handles imageFigure, depthFigure, and semanticFigure as arguments.

world = sim3d.World( ...
    Output=@OutputImpl, ...
    Update=@(world) UpdateImpl(world,imageFigure, ...
    depthFigure,semanticFigure));

Create a box actor in the 3D environment using the sim3d.Actor object and add the box to the world.

cube = sim3d.Actor( ...
        ActorName="Cube", ...
        Mobility=sim3d.utils.MobilityTypes.Movable);
createShape(cube,"box");
add(world,cube);

Create a camera object with depth and semantic data using the sim3d.sensors.Camera object. Set the location of the camera using the Translation property. Add the camera to the world.

camera = sim3d.sensors.Camera( ...
        ActorName="Camera", ...
        EnableDepthOutput = true, ...
        EnableSemanticOutput = true);
camera.Translation = [-3 0 0];
add(world,camera);

Run the co-simulation. The software displays the image, depth, and semantic data in MATLAB.

sampletime = 1/60;
stoptime = 2;
run(world,sampletime,stoptime);

function OutputImpl(world)
    world.Actors.Cube.Rotation(3) = world.Actors.Cube.Rotation(3) ...
    + 0.01; 
end

function UpdateImpl(world,imageFigure,depthFigure,semanticFigure)
    [sceneImage, sceneDepth, sceneSemantic] = read(world.Actors.Camera);

    figure(imageFigure);
    image(sceneImage);

    figure(depthFigure);
    sceneDepth(sceneDepth > 20) = nan;
    imagesc(sceneDepth);
    
    figure(semanticFigure)
    image(sceneSemantic)
end