nicklockwood / Euclid

A Swift library for creating and manipulating 3D geometry

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How to consider PIVOT when we create mesh from node or geometry

PrashantKT opened this issue · comments

let's say I have following code

    let plane = SCNBox(width: 12, height: 2, length: 12, chamferRadius: 0)
    plane.firstMaterial?.diffuse.contents = UIColor.red
    let planeNode = SCNNode(geometry: plane)
    planeNode.name = "Plane1"
    planeNode.pivot  = SCNMatrix4MakeTranslation(0, -0.5, 0)
    planeNode.geometry?.firstMaterial?.diffuse.contents = UIColor.red.withAlphaComponent(0.3)
    planeNode.scale.y = 4 //SCALE FROM BOTTOM 

Question : How can I create MESH from this object with Pivot ?

if there is no pivot I can easily create mesh with following code - But in Transformation pivot is not consider So the Created mesh is shifted

extension SCNNode {
    
    var mesh: Mesh {
        Mesh.init(self, materialLookup: nil)
    }
    
    var meshWithTransform:Mesh {
        Mesh(self) { mat in
            return mat.copy() as! SCNMaterial
        }.transformed(by: c_Transform)
        
    }
    
    var c_Transform:Transform {
        return Transform.init(offset: Vector(self.position), rotation: Rotation(self.orientation), scale: Vector(self.scale))
        
        
    }

}

Could you please guide me how to solve this

Thanks in advance

@PrashantKT I wasn't aware of the pivot property, but I'll add support for it. In the meantime, if the pivot is something simple like a translation then you can probably just pre-apply it to the Mesh before you apply the node transform. Converting an arbitrary SCNMatrix to a Transform is a little more complex though.

@PrashantKT I've pushed a quick fix to the develop branch. If you check out that branch and then create a Mesh with:

let mesh = Mesh(planeNode, ignoringTransforms: false)

It should the right thing.

@nicklockwood Thanks for quick response ,I will check it

@nicklockwood Working Great !! thank you - but in dev brach some function are missing may be you removed it
But I have added manually so no issues

/// Applies a uniform inset to the faces of the mesh.
   /// - Parameter distance: The distance by which to inset the polygon faces.
   /// - Returns: A copy of the mesh, inset by the specified distance.
   ///
   /// > Note: Passing a negative `distance` will expand the mesh instead of shrinking it.
   func inset(by distance: Double) -> Mesh {
       Mesh(polygons.insetFaces(by: distance))
   }