Collision

This must be called once on the system before any bodies with collision are stepped.

NSC (Non-Smooth Contact)

Material

friction = float     # friction coefficient
restitution = float  # restitution coefficient
mat = chrono.ChContactMaterialNSC()
mat.SetFriction(friction)
mat.SetRestitution(restitution)

Easy bodies (material passed to factory)

# Sphere
sph_radius = float   # sphere radius [m]
sph_density = float  # sphere density [kg/m³]
sphere = chrono.ChBodyEasySphere(sph_radius, sph_density, True, True, mat)
sphere.SetPos(chrono.ChVector3d(x, y, z))
sys.Add(sphere)

# Box
box_sx = float      # box width [m]
box_sy = float      # box height [m]
box_sz = float      # box depth [m]
box_density = float # box density [kg/m³]
box = chrono.ChBodyEasyBox(box_sx, box_sy, box_sz, box_density, True, True, mat)
sys.Add(box)

# Cylinder
cyl_radius = float   # cylinder radius [m]
cyl_height = float   # cylinder height [m]
cyl_density = float  # cylinder density [kg/m³]
cyl = chrono.ChBodyEasyCylinder(chrono.ChAxis_Y, cyl_radius, cyl_height, cyl_density, True, True, mat)
sys.Add(cyl)

Visual material (texture on contact body)

vis_mat = chrono.ChVisualMaterial()
vis_mat.SetKdTexture(chrono.GetChronoDataFile("textures/concrete.jpg"))
body.GetVisualShape(0).SetMaterial(0, vis_mat)

SMC (Smooth/Penalty Contact)

Material

friction = float  # friction coefficient
mat = chrono.ChContactMaterialSMC()
mat.SetFriction(friction)
# mat.SetYoungModulus(2e7)   # optional
# mat.SetPoissonRatio(0.3)   # optional

Manual body with explicit collision shapes

mass = float    # body mass [kg]
radius = float  # collision sphere radius [m]
body = chrono.ChBody()
body.SetMass(mass)
body.SetPos(chrono.ChVector3d(x, y, z))

# Add collision shape (SMC material embedded in shape)
shape = chrono.ChCollisionShapeSphere(mat, radius)
body.AddCollisionShape(shape)
body.EnableCollision(True)

# Add visual shape separately
sphere_vs = chrono.ChVisualShapeSphere(radius)
sphere_vs.SetTexture(chrono.GetChronoDataFile("textures/bluewhite.png"))
body.AddVisualShape(sphere_vs)

sys.AddBody(body)

SMC collision shapes

chrono.ChCollisionShapeSphere(mat, radius)
chrono.ChCollisionShapeBox(mat, sx, sy, sz)
# Attach at offset: body.AddCollisionShape(shape, chrono.ChFramed(pos, rot))

When to Use NSC vs SMC