Build Actor from Mesh Data and Apply Texture

This example shows how to build an actor from mesh data and apply texture using either Simulink® or MATLAB®. You can build an appearance for the actor using the createMesh function and apply texture using the Texture property of the sim3d.Actor object. A mesh is a 3D build of a model consisting of polygons and is defined by vertices, normals, and faces. This example uses the mesh data of a cube to build a cube actor. First, you create a world scene and an actor object. Next, input the mesh data to build the appearance of the actor and apply a texture. Then, you add the actor to the world and set a view in the scene. Finally, you view the actor in the Simulation 3D Viewer window.

Build Actor and Apply Texture Using Simulink

This workflow shows how to use Simulation 3D Actor block and Simulation 3D Scene Configuration block to create a virtual world with an actor. You can build the appearance of the actor from mesh data, apply a texture, and set a view in the scene to view the actor in the Simulation 3D Viewer window.

Open Model

Open the Simulink model.

open_system("CreateMeshActorAndApplyTexture");

Explore Model Components

The model includes a Simulation 3D Actor block and a Simulation 3D Scene Configuration block. The Simulation 3D Scene Configuration block implements a 3D simulation environment. Double-click the Simulation 3D Scene Configuration block to open the Block Parameters dialog box. Set a view in the scene with the Scene view parameter. You can also set a custom viewpoint with this parameter. You must include the configuration block when building Simulink models with Simulation 3D Actor blocks.

The Simulation 3D Actor block adds an actor to the virtual world. Double-click the Simulation 3D Actor block to open the Block Parameters dialog box. To create an actor before simulation starts, on the Main tab, set the Operation parameter to Create at setup. The block first creates an empty actor with the name specified in the Actor name parameter. You can use any name for the actor. Then, the block loads the source file, if any is present, and runs the Initialization script. For more details, see Operating Modes.

The Initialization script builds an actor using the createMesh function with mesh data, vertices (V), normals (N), and faces (F). This example uses the mesh data for a cube of size [1 1 1]. The mesh data contains 24 vertices, 24 normals for each of the vertices, and 12 triangular faces. Each face of the cube is made with two triangular faces, and each triangular face is made with three vertices. The input argument Texture coordinates, T, maps the texture file on to each vertices of the actor. T defines which point on the texture file maps to each of the vertices. The input argument Vertex Colors, C, specifies color for each vertex in [R G B] components. To display the vertex colors, you must set the VertexBlend property of sim3d.Actor object to a value greater than 0 and less than 1. C is optional to build an actor from mesh data. For this example, C is an empty matrix. On the Transform tab, you can also set the Initial position, Initial rotation and Actor scale of the actor.

Simulate Model

Simulate the model and view the cube actor with texture in the Simulation 3D Viewer.

sim("CreateMeshActorAndApplyTexture");

Close Model

Close the Simulink model.

close_system("CreateMeshActorAndApplyTexture");

Build Actor and Apply Texture Using MATLAB

You can use the sim3d.World and sim3d.Actor objects and functions to create a virtual world with an actor.

Create a world scene.

world = sim3d.World();

Instantiate an actor object named cube. You can use any name for the actor.

ActObj = sim3d.Actor('ActorName', 'cube');

To build an actor with createMesh function, specify the input arguments vertices (V), normals (N), and faces (F) of the mesh. This example uses the mesh data for a cube of size [1 1 1]. The mesh data contains 24 vertices, 24 normals for each of the vertices, and 12 triangular faces. Each face of the cube is made with two triangular faces, and each triangular face is made with three vertices. If you can have the vertices, normals, and faces of an actor, you can build the actor with createMesh function.

V = [-0.5 -0.5 -0.5; 0.5 -0.5 -0.5; 0.5 0.5 -0.5; -0.5 0.5 -0.5; ...
     -0.5 -0.5 0.5; 0.5 -0.5 0.5; 0.5 0.5 0.5; -0.5 0.5 0.5; ...
     -0.5 -0.5 -0.5; 0.5 -0.5 -0.5; 0.5 0.5 -0.5; -0.5 0.5 -0.5; ...
     -0.5 -0.5 0.5; 0.5 -0.5 0.5; 0.5 0.5 0.5; -0.5 0.5 0.5; ...
     -0.5 -0.5 -0.5; 0.5 -0.5 -0.5; 0.5 0.5 -0.5; -0.5 0.5 -0.5; ...
     -0.5 -0.5 0.5; 0.5 -0.5 0.5; 0.5 0.5 0.5; -0.5 0.5 0.5];

N = [0 0 -1; 0 0 -1; 0 0 -1; 0 0 -1; 0 0 1; 0 0 1; ...
     0 0 1; 0 0 1; -1 0 0; 1 0 0; 1 0 0; -1 0 0; ...
     -1 0 0; 1 0 0; 1 0 0; -1 0 0; 0 -1 0; 0 -1 0; ...
     0 1 0; 0 1 0; 0 -1 0; 0 -1 0; 0 1 0; 0 1 0];

F = [0 2 3; 0 1 2; 16 20 21; 21 17 16; 9 13 10; 10 13 14; ...
     18 22 19; 19 22 23; 11 15 8; 8 15 12; 4 7 5; 5 7 6];

The input argument Texture coordinates, T, maps the texture file on to each vertices of the actor. T defines which point on the texture file maps to each of the vertices.

T = [0 0; 1 0; 1 1; 0 1; 0 1; 1 1; 1 0; 0 0; 1 1; 0 1; 1 1; 0 1; ...
     1 0; 0 0; 1 0; 0 0; 0 1; 1 1; 0 1; 1 1; 0 0; 1 0; 0 0; 1 0];

The input argument Vertex Colors, C, specifies color for each vertex in [R G B] components. To display the vertex colors, you must set the VertexBlend property of sim3d.Actor object to a value greater than 0 and less than 1. C is optional to build an actor from mesh data and for this example, C is an empty matrix.

C = [];

Create a mesh using the actor object and mesh data. Use the image file to set the texture. Add the actor object to the world.

createMesh(ActObj, V, N, F, T, C);
ActObj.Texture = fullfile(pwd,"image.png");
add(world,ActObj);

Set Actor Transformation

Use the actor object translation, rotation, and scale properties to orient the actor relative to the world origin.

ActObj.Translation = [0 0 0];
ActObj.Rotation = [0, 0, 0];
ActObj.Scale = [1, 1, 1];

Set Viewer Window Point of View

If you do not create a viewport, then the point of view is set to 0, 0, 0, and you can use the keyboard shortcuts and mouse controls to navigate in the Simulation 3D Viewer window.

For this example, use the createViewport function to create a viewport with a single field, Main, that contains a sim3d.sensors.MainCamera object.

viewport = createViewport(world);
viewport.Translation = [-6, 0, 1.5];

Run Animation

Run a simulation set for 10 seconds with a sample time of 0.02 seconds.

run(world,0.02,10);

Delete World

Delete the world object.

delete(world)