Rotating Texture/Material of a Face

Developers Ruby API
8

One thing that might help is to study the Position Texture tool - observe how the texture pins are placed on the surface of the face.

position_material

model = Sketchup.active_model
model.active_entities.clear!

texture_path = Sketchup.find_support_file('/Materials/Brick, Cladding and Siding/Brick Colored Blue.skm')
material = model.materials.load(texture_path)

points = [ # World space coordinates
  Geom::Point3d.new(  0,   0, 0),
  Geom::Point3d.new(1.m,   0, 0),
  Geom::Point3d.new(1.m, 1.m, 0),
  Geom::Point3d.new(  0, 1.m, 0),
]
face = model.active_entities.add_face(points)
face.reverse! unless face.normal.samedirection?(Z_AXIS)

# Position texture to fit face:
uvs = [ # UV coordinates
  Geom::Point3d.new(0, 0),
  Geom::Point3d.new(1, 0),
  Geom::Point3d.new(1, 1),
  Geom::Point3d.new(0, 1),
]

mapping = [
  points[0], uvs[0],
  points[1], uvs[1],
  points[2], uvs[2],
  points[3], uvs[3],
]
# This could also be done via .zip - but the above illustrates clearer the order
# of the data.
# points.zip(uvs).flatten
face.position_material(material, mapping, true)

image

# Position tile across the face 2 times horizontally and 4 times vertically:
uvs = [ # UV coordinates
  Geom::Point3d.new(0, 0),
  Geom::Point3d.new(2, 0),
  Geom::Point3d.new(2, 4),
  Geom::Point3d.new(0, 4),
]
mapping = points.zip(uvs).flatten
face.position_material(material, mapping, true)

2022-08-23_12h34_20


# Position tile across the face 2 times horizontally and 4 times vertically.
# and rotate by 45 degrees:
uvs = [ # UV coordinates
  Geom::Point3d.new(0, 0),
  Geom::Point3d.new(2, 0),
  Geom::Point3d.new(2, 4),
  Geom::Point3d.new(0, 4),
]

# Instead of pinning the UVs to the vertices of the face, we pin them to points
# on the plane of the face. Similar to what the Position Texture tool does:
rotation_origin = Geom::Point3d.new(0, 0)
tr = Geom::Transformation.rotation(rotation_origin, face.normal, 45.degrees)
face_points = points.map { |uv| uv.transform(tr) }

mapping = face_points.zip(uvs).flatten
face.position_material(material, mapping, true)

image

image
image782×542 87.7 KB

In the above illustration the red square are the points on the face of the plane, they are rotated 45 degrees of the original vertices. Because the UV values remain the same you get the desired rotation. (Did that make sense?)

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