Adjacent

Adjacent is a geometric constraint solver implemented in C++. It is heavily inspired by NoteCAD by Alexey Egorov, an open-source CAD program written in C#/Unity.

Adjacant comes with a C++ and a Python interface.

Installation

For the installation, you need cmake, xtensor, xtl, and a recent C++ compiler. If you want to build the Python bindings as well, you will need to additionally install pybind11.

You can install these dependencies using mamba (or conda).

mamba install cxx-compiler cmake xtensor pybind11 -c conda-forge

Then you can build the project by doing

conda activate
mkdir build; cd build
cmake .. -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX
make
make install

Python examples

from adjacent_api import *

# Adjacent computes everything symbolically so we need to create named parameters

x = Param("x", 0.0)
y = Param("y", 5.0)
z = Param("z", 1.0)

# Now we can create a point at (0, 5, 1)
p1 = Point(x, y, z)

# helper function
def point(name, xyz=(0, 0, 0)):
    if len(xyz) <= 2:
        xyz = (*xyz, 0)
    return Point(Param(f"{name}_x", xyz[0]), Param(f"{name}_y", xyz[1]), Param(f"{name}_z", xyz[2]))

p2 = point("p2", (3, 1, 2))
p3 = point("p3", (5, 5, 9))
p4 = point("p4", (1, 2, 9))
p5 = point("cc1", (1, 1))

l1 = Line(p1, p2)
l2 = Line(p3, p4)
c1 = Circle(p5, Param("rad1", 1.2))

s = Sketch()

s.add_entity(l1)
s.add_entity(l2)
s.add_entity(c1)

DESIRED_ANGLE = -0.8 * math.pi

# Let's add some constraints to the sketch
s.add_constraint(constraints.Coincident(p2, p4))
s.add_constraint(constraints.Diameter(c1, 2.5))

s.add_constraint(constraints.Coincident(p1, p5))
# s.add_constraint(constraints.Tangent(c1, l1))

s.add_constraint(constraints.Length(l1, 5))
s.add_constraint(constraints.Length(l2, 1.5))

# Horizontal / Vertical constraint
s.add_constraint(constraints.HV(l1, constraints.HVOrientation.OY))

# s.add_constraint(constraints.HV(l2, constraints.HVOrientation.OY))
s.add_constraint(constraints.Angle(l1, l2, DESIRED_ANGLE))
# s.add_constraint(constraints.Parallel(l1, l2))
# s.add_constraint(constraints.HV(l1, constraints.HVOrientation.OX))
# s.add_constraint(constraints.Length(l2, 1.5))
# s.add_constraint(constraints.Distance(p2, p3, 0.5))
# s.add_constraint(constraints.PointOn(p3, l1))

# And solve!
s.update()

print("L1: ", l1)
print("L2: ", l2)
print("C1: ", c1)