曲线

Examples

Initialization

A Curve can be initialized:

• by typecasting another geometry

• or by using a constructor such as Line, Circle, Spiral

import geonodes as gn

with gn.Tree("Test") as tree:

    # Typecasting the tree input geometry
    
    curve = gn.Curve(tree.ig) # Hope it is really a curve
    
    # We create a cube
    
    circle = gn.Curve.Circle()
    circle.set_position(offset=(0, 0, 2))
    
    # We return the two meshes
    
    tree.og = curve + circle

To mesh conversion

Use to_mesh method to transform the curve into a Mesh.

import geonodes as gn

with gn.Tree("Test") as tree:
    
    # Which radius do you want
    
    radius = gn.Float.Input(.1, "Radius", min_value=0.001, description="The curve radius")

    # Let's start from a spiral    
    spiral = gn.Curve.Spiral()
    
    # To mesh
    
    mesh = spiral.to_mesh(gn.Curve.Circle(radius=radius), fill_caps=True)
    mesh.faces.shade_smooth = True
    
    # Done
    tree.og = mesh

UV Mapping from curve factor

In the following example, we use the curve parameter to build the UV map of a torus. Here the UV mapping is stored as corner named attribute ‘uv_map’ into the geometry. It can be accessed through Attribute material shader node.

import geonodes as gn

with gn.Tree("Torus") as tree:
    
    segms = gn.Integer.Input(32, "Segments",     min_value=3)
    rings = gn.Integer.Input(32, "Rings",        min_value=3)
    R     = gn.Float.Input(1.,   "Major radius", min_value=0.001)
    r     = gn.Float.Input(.25,   "Minor radius", min_value=0.001)
    mat   = gn.Material.Input(None)
    
    with tree.layout("Base torus"):
    
        major = gn.Curve.Circle(resolution=rings, radius=R)
        minor = gn.Curve.Circle(resolution=segms, radius=r)
        
        u = major.points.parameter_factor
        v = minor.points.parameter_factor
    
        major.points.set_named_float("u", u)
        minor.points.set_named_float("v", v)
        
        torus = major.to_mesh(profile_curve=minor)
        
    with tree.layout("UV Mapping"):
        
        u = torus.get_named_float("u")
        v = torus.get_named_float("v")
        
        torus.corners.set_named_vector("uv_map", (u, 1 - v, 0))
        
        torus.remove_named_attribute("u")
        torus.remove_named_attribute("v")
        
        torus.faces.material = mat
    
        
    tree.og = torus

Final

from imare import *
init_modules(__file__, "imare", "geonodes")
flush_data()

import geonodes as gn
from geonodes.nodes import nodes

mat = bpy.data.materials.new("a")
mat.diffuse_color = (1, 0, 0, 1)

# 用几何节点计算并保存UV

with gn.Tree("Geometry Nodes", reroute=False, shift=False) as tree:
    ring_seg = gn.Integer.Input(32, "Ring Segments")
    pipe_seg = gn.Integer.Input(32, "Pipe Segments",)
    ring_rad = gn.Float.Input(1., "Ring radius")
    pipe_rad = gn.Float.Input(.25, "Pipe radius")
    mat = gn.Material.Input("a")

    with tree.layout("Base torus"):

        major = gn.Curve.Circle(resolution=ring_seg, radius=ring_rad)
        minor = gn.Curve.Circle(resolution=pipe_seg, radius=pipe_rad)

        u = major.points.parameter_factor
        v = minor.points.parameter_factor

        # u = major.points.index
        # v = minor.points.index

        major.points.store_named_float("u", u)
        minor.points.store_named_float("v", v)

        torus = major.to_mesh(minor)

    with tree.layout("UV Mapping"):

        u = torus.named_float("u")
        v = torus.named_float("v")

        torus.corners.store_named_vector("uv_map", (u, 1 - v, 0))

        torus.remove_named_attribute("u")
        torus.remove_named_attribute("v")

        torus.faces.material = mat

    tree.og = torus


Tree({
    O.cube: {
        Mod.geometry_nodes: {
            "node_group": "Geometry Nodes",
        },
    },
}).load()
bpy.context.scene.frame_end = 90