How do I modify the custom aircraft files refered to in "path to custom mesh" in the "Simulation 3D Aircraft" block

'/MathWorksAerospaceContent/Vehicles/Aircraft/Custom/Mesh/SK_HL20.SK_HL20'

I was unable to find this referenced file path in the root or docoments folder of MATLAB, where I would I have expected it to be.

There is a path generated in the once I installed the Aerospace Blockset Interface for Unreal Engine Projects, but changing the files in that folder by Unreal Editor or otherwise had no impact on the model shown when running the Simulation 3d viewer via Simulink.

Answer 1

[Nishan Nekoo]

Hi Elias,

The file containing the default actors of the Simulation 3D Aircraft block that appear in the Simulation 3D Viewer via Simulink are not accessible in the root or documents folder of MATLAB and cannot be modified. However, a copy of them is available in the support package you downloaded as you have noted. Once you have modified the file, you can reference the path of this new file in the Simulation 3D Aircraft block in the 'Path to custom mesh' field once you select 'Custom' in the 'Type' field of the block.

I hope that helps!

NIshan

[Elias]

Hey Nishan,

thanks that clears some stuff up for me. Still I was unable to reference the path that was copied to the Unreal Engine folder, also copying it into my current search path odly didn´t help me either. Perhaps you could give me an example how to reference a modifiable path.

[Nishan Nekoo]

Hey Elias,

A few questions so I can better understand the issue you are seeing:

1. What version of MATLAB are you using?
2. What kind of modifications are you making to the mesh?
3. "unable to reference the path that was copied to the Unreal Engine folder" - When you say unable to, what do you mean by that exactly? Are you seeing an error of some sort or are you just not seeing the modifications that you wanted.

Nishan

[Elias]

Hey Nishan,

1. 2024a
2. my first goal would be just to exchange the visual mesh without touching the skeleton
3. The error message says: Assertion failed: ... Failed to load [custom path name] . Please specify a valid path

I´ve tried referencing the path by "C:\Program Files\Epic Games\UE_5.1\Engine\Plugins\Marketplace\MathWorks\MathWorksAerospaceContent\Content\Vehicles\Aircraft\Custom\Mesh\SK_HL20.SK_HL20" and by copying it to my search path and referencing it from there.

Thanks for your help

[Nishan Nekoo]

Hey Elias,

Thanks for answering those questions, I was able to reproduce the error that you highlighted above. I think there are a couple things to understand here that are definitely not obvious and that I had to investigate myself:

1. When you first select 'Custom', the following path gets populated '/MathWorksAerospaceContent/Vehicles/Aircraft/Custom/Mesh/SK_HL20.SK_HL20' as you have noted. This HL20 mesh that has been prepared for use as a 'Custom' mesh is internal to the Unreal Engine executable that we ship with the Simulink 3D Animation (AutoVrtlEnv.exe) and is not accessible anywhere.
2. The good news is the "unprepared" mesh is available to you as you have noted in "C:\Program Files\Epic Games\UE_5.1\Engine\Plugins\Marketplace\MathWorks\MathWorksAerospaceContent\Content\Vehicles\Aircraft\Custom\Mesh\". To successfully specify this mesh as a custom mesh, it first needs to be "prepared" according to the instructions here: https://www.mathworks.com/help/aeroblks/prepare-custom-vehicle-mesh-for-the-unreal-editor.html

Hopefully that helps, and please don't hesitate to reach out if you have trouble going through the custom mesh workflow. We didn't provide the "prepared" custom mesh of the HL20 since users usually have their own custom meshes they would want to use.

Nishan

[Elias]

Hey Nishan,

This is very helpful. I was hoping to test the general process without having to prepare a fully functioning mesh because I only have a static mesh atm. I´ll try following the guide step by step then first. Ty

[Nishan Nekoo]

Hey Elias,

If you only have a static mesh in the form of an STL or FBX for example, you can import that using a Simulation 3D Actor block instead of using the Simulation 3D Aircraft. Simply specify the path to your source file in the Simulation 3D Actor and that should be a much easier way to get your static mesh into a scene.

Check out these examples:

https://www.mathworks.com/help/sl3d/build-actor-from-imported-3d-file-using-simulink.html

https://www.mathworks.com/help/sl3d/simulate-a-quadcoptor.html

One other thing to note is that if you go through the mesh preparation process, you can specify the minimum set of bones you need (just the BODY for example), and don't have to specify all of them.

Nishan