Procedural Mesh Not Responding to Line Trace

[wox_pl]

Hi everyone,

I’m encountering a persistent issue where my procedural mesh created using the “Procedural Mesh Component” in Blueprints isn’t responding to line traces, despite seemingly having collision enabled. I’ve tried numerous troubleshooting steps, but I’m still unable to get the line trace to detect the mesh.

Here’s a summary of what I’ve done:

1. Created a Procedural Mesh:
   I’m generating a simple shape using vertices and triangles in the Construction Script of my Actor Blueprint.

2. Collision Settings:

• I’ve set the mesh to “Use Complex as Simple” collision.
• The collision preset is set to “BlockAll.”

3. Line Trace Setup:
   I’ve implemented a line trace by channel (using “Visibility” channel) in the Event Graph of the same blueprint, starting from a point and tracing forward.

4. Debug Draw:
   I’ve enabled the “Draw Debug Type” for the line trace to visualize it, and I can see the line trace being drawn correctly.

5. No Hit on Procedural Mesh:
   The line trace hits other static meshes in the scene, but it completely ignores the procedural mesh.

6. Additional Tests:

• I added a bouncing ball to the scene, and it correctly collides with and bounces off the procedural mesh.
• I can walk on the procedural mesh using the player pawn, confirming that basic collision is working.
• I’ve tried different trace channels and object types, but the result is the same.
• I even tried replacing the procedural mesh with a simple box collision mesh, and the line trace still fails to detect it.

Here’s a screenshot of my Blueprint setup:

Link to a video:
Recording 2025-03-11 210838.mp4

[sergio.gardeazabal]

Hi, Welcome to the forum!

On what version of UE are you working on?

If you are working on UE 5.4 or 5.5 you can use the Chaos Visual Debugger to confirm

• The query is happening as you expect (you should have covered this with the use of debug draw)
• The query is done with the params you expect
• The physics engine has collision geometry for the mesh you created. If you don’t see in in CVD (for short) it means there mesh does not have collision. Given that you mention you can walk on it and other objects collide against it, I assume the collision geometry is correct, but CVD might help to confirm it.

In the 5.5 version of CVD you are also able to select an object inside CVD while holding the left shift key, and that will show you in the details panel the collision channel responses for that object as the Chaos sees it (which can help to see if the mesh has the collision channel Reponses you expect, and matches the query you are doing).

Here is the documentation for the 5.5 version Chaos Visual Debugger - User Guide for UE 5.5 | Tutorial.

For scene queries specifically

Chaos Visual Debugger - User Guide for UE 5.5 | Tutorial

If you are using UE 5.4, there are less features available in CVD and the defaults are not ideal you need to make sure that the necessary Geometry visualization flags are enabled Chaos Visual Debugger - User Guide for UE 5.4 | Tutorial). But still should have most of the information needed available.