ANYtk3D

Fast dependency-free 3D drawing on a Tkinter Canvas.

ANYtk3D is the standalone 3D viewport extracted from ANYstructure. It renders solids, stiffened plates, cylinders and arbitrary meshes directly on a tkinter.Canvas — no OpenGL, no matplotlib, only numpy and the standard library.

Features

• Typical shapes out of the box — box, sphere, cone, truncated cone, cylinder, tube/pipe, torus, pyramid, wedge, prism, swept extrusion, disk/annulus, plane, arrow, ground grid, structural beam profiles (FB, T, I, L, C, BOX) and arbitrary index meshes
• Directional lighting — ambient + Lambert diffuse + Blinn-Phong highlight, flat-shaded per face, two-sided, world-fixed or head-lamp
• Correct depth order — every face is painted back to front by camera-space depth, closed solids cull their back faces, faces straddling the near plane are clipped instead of dropped, and 3D lines take part in the same sort
• Layered transparency — 16 screen-door density steps with non-overlapping windows per layer, so a transparent shell shows its far wall, its contents and its near wall at once
• Built for speed — geometry is compiled to numpy arrays once and every frame is vectorised; canvas items are pooled and only reconfigured when their appearance changes; the interactive level of detail self-tunes from measured frame times
• Result fields and animation — a batched add_faces call for meshes coloured per element, plus frame capture and playback that adapts its detail to the requested frame rate
• Camera orbit, zoom and pan; plate colour-coding by thickness (or any scalar) with a fixed legend; X/Y/Z axis overlay and optional rulers; animation caching and playback

Installation

pip install ANYtk3D

Tkinter ships with the standard CPython installers.

Quick start

import tkinter as tk
from anytk3d import Point3D, Tkinter3DCanvas

root = tk.Tk()
canvas = Tkinter3DCanvas(root, width=900, height=600, bg='white')
canvas.pack(fill='both', expand=True)

canvas.add_box(2.0, 1.0, 0.5, center=Point3D(-3, 0, 0.25), color='#4e79a7')
canvas.add_sphere(0.8, center=Point3D(0, 0, 0.8), color='#f28e2b')
canvas.add_tube(0.8, 0.5, 2.0, center=Point3D(3, 0, 1.0), color='#59a14f')
canvas.add_beam(Point3D(-4, 3, 0), Point3D(4, 3, 0), kind='I',
                web_height=0.6, flange_width=0.3)
canvas.add_grid(size_x=12, size_y=10)

canvas.fit_to_scene()
root.mainloop()

Shapes

add_box, add_box_from_bounds, add_sphere, add_cone, add_frustum, add_cylinder, add_tube, add_torus, add_pyramid, add_wedge, add_prism, add_extrusion, add_disk, add_plane, add_arrow, add_beam, add_grid, add_mesh, add_shape, plus the original add_polygon, add_line, add_text, add_rectangular_plate, add_flat_stiffener, add_flat_girder, add_longitudinal_stiffener and add_ring_stiffener.

Every shape builder takes center/axis placement and the same material keywords — color, outline, opacity, layer, cull_backface, lit, back_color, face_colors, tags.

The tessellation lives in anytk3d.shapes as plain functions returning a Mesh (vertices plus index faces), so it can be used, combined and tested without a display:

from anytk3d import shapes

mesh = shapes.torus(2.0, 0.4).merged(shapes.sphere(0.5))
canvas.add_shape(mesh, position=Point3D(0, 0, 3), color='#b07aa1')

Lighting

canvas.set_light(direction=Point3D(0.4, -0.6, 0.7), ambient=0.45,
                 diffuse=0.55, specular=0.12)
canvas.set_light(follow_camera=True)   # head lamp that orbits with the view
canvas.set_shading(False)              # flat colours, no shading

Ambient and diffuse sum to 1.0 by default, so a face turned toward the light renders in its exact base colour and every other face only darkens. That keeps colour-coded scenes matching their legend.

Transparency

opacity runs from 0 to 1 in 16 usable steps. A Tk canvas has no alpha channel, so this is screen-door stippling — but the front and back of a surface are given non-overlapping dither windows, sized so that stacking them reproduces ordinary alpha compositing (1 - (1 - a)^2). Passing an explicit stipple= string still uses that exact Tk pattern.

canvas.add_sphere(2.0, color='#7fb3d5', opacity=0.35)   # see the contents
canvas.add_box(1.0, 1.0, 1.0, color='#c0392b')          # ...through the shell

Colour scale

Plate colour-coding, the legend and thickness_color all share one scale. Replace it to use a different colour map — sample any ramp at a handful of positions and hand the stops over:

from matplotlib import colormaps, colors   # only if you want matplotlib maps
import anytk3d

stops = [(t / 16, colors.to_hex(colormaps['viridis'](t / 16))) for t in range(17)]
anytk3d.set_color_stops(stops)
anytk3d.get_color_stops()
anytk3d.reset_color_stops()                # back to the built-in blue→red ramp

Colours a canvas resolved itself (cylinder plate thickness, stiffener thickness) refresh on the next redraw. anytk3d.DEFAULT_COLOR_STOPS is the built-in scale; assigning to the old _THICKNESS_COLOR_STOPS constant has no effect — use set_color_stops.

Result fields

add_faces is the batched path for a mesh where every element carries its own colour — an FE stress plot, a deformed shape, a utilisation map. It takes the whole element set in one call and computes all the centroids and normals as array operations:

canvas.add_faces(polygons, colors=element_colors, outline='#64748b')
canvas.set_thickness_legend([0, 80, 160, 240], unit='MPa', title='von Mises')

polygons is a sequence of vertex sequences (Point3D or (x, y, z)), or an (faces, vertices, 3) array. On a 4900-element field this compiles in 4.5 ms against 48 ms for the same elements added one at a time.

Animation

Capture a scene per step, then replay it:

canvas.begin_animation_cache()
for step in range(frames):
    canvas.clear(keep_canvas=True)
    canvas.add_faces(deformed_shape(step), colors=field_colors(step))
    canvas.capture_animation_frame()
canvas.play_animation(fps=30)          # fast=None/True/False

A scene without cylinders or stiffeners compiles to a single shared representation, so each captured frame costs one build rather than two. Playback defaults to fast=None, which starts at full detail and drops to the reduced-detail path as soon as a frame overruns its slot; pass True or False to pin it. animation_frames, animation_frame_index and is_playing_animation are available for a progress readout.

Performance

Interactive frames use a reduced-detail scene with a face budget that adapts to the measured frame rate, so orbiting stays responsive on dense models and full detail returns when the mouse is released.

canvas.set_interactive_detail(4000)   # starting face budget while dragging
canvas.set_mesh_lines(False)          # drop per-face outlines
canvas.set_occlude_lines(False)       # keep 3D lines on top of geometry

Demos

The interactive showcase — shapes with live light controls, a colour-coded FE result field, animation playback with a measured frame rate, and a stiffened cylinder — is a single file you can run straight from an IDE (right-click → Run in PyCharm) or from a shell:

python -m anytk3d.demo

The original four-viewport demo is still there:

python -m anytk3d

or embed it in an existing Tk application with anytk3d.create_stiffened_cylinder_demo(root).

Relation to ANYstructure

ANYstructure uses this package for its 3D previews. The module keeps its original API (Tkinter3DCanvas, Point3D, Camera3D and every add_* method) so it stays a drop-in dependency.

Development

pip install -e .[dev]
pytest

License

GPL-3.0-or-later. See LICENSE.