alignScopeToGeometry operation


alignScopeToGeometry(upAxis, faceIndex, edgeIndex)

alignScopeToGeometry(upAxis, faceSelector, edgeIndex)

alignScopeToGeometry(upAxis, faceIndex, edgeSelector)

alignScopeToGeometry(upAxis, faceSelector, edgeSelector)



The alignScopeToGeometry operation manipulates the scope, the pivot and the geometry attributes in the following way:

  1. select new pivot axis directions (defined by upAxis selector and the selected face and edge, see below)
  2. calculate the oriented bounding box (OOB) for the geometry along these axes and set pivot.p to the origin of the OOB. The new scope dimensions are set to the OOB.
  3. transform the geometry into this new coordinate system.

The parameters let you choose an edge of a face in the geometry. The new x-axis of the scope will be parallel to this edge, and the up-axis will be the face's normal.

The geometry is projected to the new scope (i.e. stays at the same place in world coordinates).



Aligning to the lowest edge

initial scene
A--> comp(f){ 25 : Faces }

The initial scene: After a face component split, the scope (and pivot, fat) happen to be positioned such that the y-axis points towards the ground.

after alignScopeToGeometry with auto
A--> comp(f){ 25 : Faces }
     alignScopeToGeometry(zUp, any, world.lowest)

Applying alignScopeToGeometry with the any and world.lowest selectors guarantees that the y-axis of the scope points upwards.

This is very useful e.g. for placing bricks on a roof.


Basic usage

initial scene
A -->
        0:  color("#ff0000") t(0,0,0.01) X |
        32: color("#0000ff") t(0,0,0.01) X }

The initial scene: A mesh is inserted and two faces highlighted by applying a component split.

after alignScopeToGeometry with auto The same scene, with scope and pivot of shape B highlighted.
after alignScopeToGeometry with auto
B -->
     alignScopeToGeometry(zUp, 1) 

After alignScopeToGeometry, the pivot's (and the scope's) x-axis points along edge 1 of face 0 (red); the z-axis points along the face normal and the x-axis is normal to the two others. The pivot is positioned at the edges starting point and the scope is the pivot-aligned bounding box of the geometry.

after alignScopeToGeometry with auto
B -->
    alignScopeToGeometry(yUp, 32, 2) 

Here, the second edge of face 32 (blue) is used, and the face-normal becomes the new y-axis.

after alignScopeToGeometry with auto
B -->
      alignScopeToGeometry(yUp, any, world.lowest) 

In this case, "any" and "world.lowest" select the edge with lowest y-position (in world coordinates), which becomes the new x-axis, and the corresponding face-normal becomes the new y-axis (because of the yUp selector).

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