3.1 Assembly

Create a new project using the URealXR template.

Configure the Content Browser to suit your workflow for efficient development.

In the folder VRAssembling/Meshes, you will find a 3D model named SM_Battery_Frame. Drag this model into the viewport and place it at the edge of the table.It should look as follows.

Now we start the URealXR Toolset and navigate to the "Transformer" tab. To do this, go to the Editor folder and right-click on "Start". Then select "Run Editor Utility Widget".

On the right side, we select our desired Transformer — in this case, the Spline Movement. Directly below, under the "Selected" section, we can see our current selection in the viewport — in this case, the SM_Battery_Frame.

Now we move to the other side. Under Common / Slot Name, we can enter any name that best describes the object — in our case, we’ll use "Gear".

The choice between "Assembly" and "Disassembly" in the URealXR Toolset indicates whether the object (in this case, the drawer) should be assembled or disassembled in the VR environment.

If you select "Assembly", it means the drawer is not yet mounted in the VR scene and must be placed by the user at a predefined location. Since your goal is assembly, choosing "Assembly" is the correct step.

Now let's turn our attention to the other settings: under Spline Movement / Grab Method, you will find a dropdown menu offering several options.

1. No Grab: You don't need to grab the object using the grab button. Simply placing your hand on the object and moving it along the path is sufficient.

2. Grab Backwards: If you want to push the object, you need to use the grab button. For pulling or general interaction, a simple touch is sufficient.

3. Grab Forward: To move the object forward along the spline (e.g., push it), you must press and hold the grab button. Simply touching the object is not enough. Pulling it backward, however, can be done without grabbing—just by touching and moving it.

4. Grab Always: To move the object in any direction along the spline—whether forward or backward—you must always press and hold the grab button. Simply touching the object has no effect.

5. 

In our case, we select Grab Always.

Initial spline percent:

This parameter determines the starting position of the object along the spline path.

The value ranges from 0.0 to 1.0, where:

• 0.0 = start of the spline

• 1.0 = end of the spline

For example, a value of 0.25 means the object will initially be placed 25% along the spline.

For our demo, we use a value of 0, which means the object starts at the very beginning of the spline.

Finally, click the "Spawn" button.

Switch to the viewport and take a look at the Outliner. As you can see, two objects have been created:

• 1_BP_Part_Spline: This serves as the interactable object for the VR user. It can be grabbed and moved.

• 1_BP_Slot_Holo_Spline: This acts as a placement guide. The task is only considered complete once the object has been placed and pushed to the correct position along the path.

Now select the part in the viewport and move it to the left. This will make the two newly created objects easier to see.

To activate the target location where the drawer should be placed, you first need to enable it.

We do this as usual using the Task Editor.

Switch to the Tasklist Editor at the top and create a new list. Name it accordingly, then create a new section that includes a task.

Assign the task to the actor that is listed under "Unused", and set it to Assembly. It should look like this.

Now try it out in VR. It should only be possible to place the drawer and then pull it toward you.

Now, in the next step, we want to add another task using the Task Editor in order to present an additional feature.

Create a new task, link the spline movement actor as before, and this time set the actor to 'Pull'. The result should look as follows

And finally, we add one more task. This time, we set the actor to 'Disassemble'. The result should look as follows.

Now start the application in VR.

The process should look as follows:

First, you position the drawer and pull it towards you to complete the first step.

In the second step, you push the drawer away from you.

In the final step, you remove the drawer again.