Getting some odd results from Raycast GetCollisionFaceIndex

Petey

Hi all!

Just trying to get some data from a raycast hit and it's coming up with some odd results.
In this simple script, I'm getting the face index from a raycast hit, then highlighting the connected verts.

if (raycast.IsColliding())
        {
            meshDataTool.CreateFromSurface(arrayMesh, 0);
            var collisionFaceIndex = raycast.GetCollisionFaceIndex();
            for (var i = 0; i < 3; i++)
            {
                var vertexIndex = meshDataTool.GetFaceVertex(collisionFaceIndex, i);
                var vertex = meshDataTool.GetVertex(vertexIndex);
                DebugDraw3D.DrawSphere(vertex, 0.05f, Colors.GreenYellow);
            }
        }

Here's the result.

Not sure where things are going wrong here. Maybe some sort of mesh optimisation messing up the vert numbers? Hopefully it's just something I'm doing wrong 🙂

Any ideas?
Thanks!
Pete.

xyz

Petey Conquer the simple things first, like proper code formatting, before attempting to tackle more advanced ones. Gotta be able to walk before you try running.

kuligs2

not sure what are you trying to get? why not just get xyz vert and put that sphere on that collision point? This is documented in the docs. too lazy to google the link

Petey

kuligs2 Getting the collision point would be way easier for sure, but I eventually want to get some other data from the collision point. So I’m just trying to simplify it down to figure out why it seems to be getting the wrong vert.

xyz Yeah, that turned out looking terrible :/ . I did use the code option. Maybe it doesn’t recognise C#?

xyz

Petey Spend some time with the right reference manual. That's what quality coders habitually do when things go awry. Hint: Flarum uses Markdown.

kuligs2

the code

the code tags produce only single quotes thingies, but ` and ` maybe web devs need to fix it to triplets? ```

also to paste code here use triplets
```
code goes here
```

it will look like

func _ready():
	if multiplayer.is_server():
		print_once_per_client.rpc()

@rpc
func print_once_per_client():
	print("I will be printed to the console once per each connected client.")

Tomcat

kuligs2 the code tags produce only single quotes thingies, but and maybe web devs need to fix it to triplets? ```

If multiple lines are selected, then when clicking on “insert code” </>, there will be triple quotes. ```

00 code
01 code

kuligs2

Tomcat how can you selecet multiples of nothing?

the guy copied code from his IDE, then came here, found the code button, pressed it, and pasted his code..

its not his fault, i have done this too, when first was using the forum.

xyz

kuligs2 how can you selecet multiples of nothing?

The least that could be done is to change code button's tooltip from "insert code" to "format as code block". This will hint that something should/may be selected prior to pressing this button, instead of pressing the button being the initial thing to do when you want to post some code, as it kinda suggests now.

Or alternatively two buttons could exist; "insert inline code" and "insert block code"

The solutions are many but there's no will to implement them.

Petey

Oh thanks! I missed this 🙂 Got it working now 👍️

    if (raycast.IsColliding())
    {
        meshDataTool.CreateFromSurface(arrayMesh, 0);
        var collisionFaceIndex = raycast.GetCollisionFaceIndex();
        for (var i = 0; i < 3; i++)
        {
            var vertexIndex = meshDataTool.GetFaceVertex(collisionFaceIndex, i);
            var vertex = meshDataTool.GetVertex(vertexIndex);
            DebugDraw3D.DrawSphere(vertex, 0.05f, Colors.GreenYellow);
        }
    }

Could the meshDataTool change the face order at all? raycast.GetCollisionFaceIndex returns a valid index but then meshDataTool.GetFaceVertex seems to be referencing another face. 🤔

ProbablyPrinting

Did you ever arrive at a conclusion about the original question? I too am experiencing a disconnect between the face-index from get_collision_face_index() and the faces used by MeshDataTool.

My working theory the same as yours, that the mesh data is not the same.