roofHip operation



roofHip(angle, overhang)

roofHip(angle, overhang, even)

roofHip(valueType, value)

roofHip(valueType, value, overhang)

roofHip(valueType, value, overhang, even)



The roofHip operation builds a hip roof perpendicular to each face of the current shape's geometry. At every edge, a plane is generated with a given angle or height wrt. the polygon plane. All planes are cut with each other to form the roof faces.

If overhang is set, the roof faces overlap the original shape by this distance. Overhang distances are measured perpendicular to the shape edges (on the roof planes).

If even is set to true, the gable edges are forced to be horizontal. In this case, non-planar roof faces originate.

The connectivity of the roof mesh is optimized for trim plane generation to cut bricks inserted into the roof planes (see examples below).


The scope orientation is set in the following way:

The scope's sizes are adjusted to tighly fit the extruded geometry.

Component tags

The operation automatically applies semantic component tags to the resulting face components:
"roof.bottom"Blue: original face.
""Green: roof faces.

For more information on working with component tags, refer to:



Simple Hip Roof

A basic hip roof is generated on top of an extruded L-lot.

Lot  --> extrude(10) Mass
Mass --> comp(f) { top: Top | all: X }
Top  --> roofHip(30, 2) Roof
A hip roof with roof slope 30 degrees is built on top of an extruded L-lot. The overhang distance is set to 2. Note the setting of the pivot and scope.

Roof --> set(trim.horizontal, true)
         comp(f) { all : X }
After a component split, each roof face contains trim planes to cut bricks on insertion.

Note that per default there are no horizontal trim planes at the ridges. To enable them, set(trim.horizontal, true) is used in front of the component split (details).

Note that there is exactly one roof face perTop shape edge. Unfortunately in the images it seems like the overlap is in a separate face. However, the simple reason for this is that the edges of the shapes in behind bleed through.

Even Hip Roof

This example demonstrates the difference between a standard and an even hip roof built on a trapezoid-lot.

Lot  --> extrude(10) Mass
Mass --> comp(f) { top: Top | all: X }
Top  --> roofHip(45, 1, false) Roof
A hip roof with roof slope 45 degrees is built on top of an extruded trapezoid-lot. The overhang is set to 1. Note that the ridge is uneven.

Top  --> roofHip(45, 1, true) Roof
When using the above rule for theTop shape, the ridge vertices are set to the average height, making the hip roof even.

The roof faces are non-planar now.

For many shapes, ridges get implicitly even and hence the even option doesn't change anything.

Copyright ©2008-2023 Esri R&D Center Zurich. All rights reserved.