simvx.core.mesh_builder

Procedural geometry construction tool.

MeshBuilder provides a vertex-by-vertex mesh building API: set the attributes that apply, add a vertex, and commit a Mesh at the end. ImmediateGeometry3D rebuilds its mesh every frame from a user callback, suitable for debug visualisations, trails, and dynamic geometry. Primitive shapes come from the Mesh classmethods (Mesh.box(), Mesh.plane(), Mesh.sphere() and the rest).

Usage::

from simvx.core import MeshBuilder, PrimitiveType

st = MeshBuilder()
st.begin(PrimitiveType.TRIANGLES)
st.set_normal((0, 1, 0))
st.set_uv((0, 0))
st.add_vertex((0, 0, 0))
st.set_uv((1, 0))
st.add_vertex((1, 0, 0))
st.set_uv((0.5, 1))
st.add_vertex((0.5, 1, 0))
mesh = st.commit()

Module Contents

Classes

PrimitiveType	Primitive topology for MeshBuilder.
MeshBuilder	Vertex-by-vertex mesh construction tool.
ImmediateGeometry3D	A 3D node whose mesh is rebuilt every frame via a callback.

Data

log
__all__

API

simvx.core.mesh_builder.log

‘getLogger(…)’

simvx.core.mesh_builder.__all__

[‘MeshBuilder’, ‘PrimitiveType’, ‘ImmediateGeometry3D’]

class simvx.core.mesh_builder.PrimitiveType

Bases: enum.IntEnum

Primitive topology for MeshBuilder.

Initialization

Initialize self. See help(type(self)) for accurate signature.

TRIANGLES

0

LINES

1

POINTS

2

TRIANGLE_STRIP

3

__abs__()

__add__()

__and__()

__bool__()

__ceil__()

__delattr__()

__dir__()

__divmod__()

__eq__()

__float__()

__floor__()

__floordiv__()

__format__()

__ge__()

__getattribute__()

__getnewargs__()

__getstate__()

__gt__()

__hash__()

__index__()

__int__()

__invert__()

__le__()

__lshift__()

__lt__()

__mod__()

__mul__()

__ne__()

__neg__()

__new__()

__or__()

__pos__()

__pow__()

__radd__()

__rand__()

__rdivmod__()

__reduce__()

__reduce_ex__()

__repr__()

__rfloordiv__()

__rlshift__()

__rmod__()

__rmul__()

__ror__()

__round__()

__rpow__()

__rrshift__()

__rshift__()

__rsub__()

__rtruediv__()

__rxor__()

__setattr__()

__sizeof__()

__str__()

__sub__()

__subclasshook__()

__truediv__()

__trunc__()

__xor__()

as_integer_ratio()

bit_count()

bit_length()

conjugate()

class denominator

class imag

is_integer()

class numerator

class real

to_bytes()

__deepcopy__(memo)

__copy__()

name()

value()

class simvx.core.mesh_builder.MeshBuilder

Vertex-by-vertex mesh construction tool.

Accumulates vertex attributes then emits a Mesh on commit(). Set per-vertex attributes (normal, uv, colour) before calling add_vertex() – the current values are latched when the vertex is added.

Initialization

__slots__

(‘_primitive’, ‘_positions’, ‘_normals’, ‘_uvs’, ‘_colours’, ‘_indices’, ‘_cur_normal’, ‘_cur_uv’, ‘…

begin(primitive: simvx.core.mesh_builder.PrimitiveType = PrimitiveType.TRIANGLES) → None

Start a new surface. Clears any previously accumulated data.

set_normal(normal: collections.abc.Sequence[float] | simvx.core.math.types.Vec3) → None

Set the normal for subsequent vertices.

set_uv(uv: collections.abc.Sequence[float] | simvx.core.math.types.Vec2) → None

Set the UV coordinate for subsequent vertices.

set_colour(colour: collections.abc.Sequence[float]) → None

Set the vertex colour (RGBA) for subsequent vertices.

add_vertex(position: collections.abc.Sequence[float] | simvx.core.math.types.Vec3) → None

Add a vertex with the currently set attributes.

add_index(index: int) → None

Add an index referencing a previously added vertex.

add_triangle_fan(vertices: collections.abc.Sequence[collections.abc.Sequence[float]], uvs: collections.abc.Sequence[collections.abc.Sequence[float]] | None = None, normals: collections.abc.Sequence[collections.abc.Sequence[float]] | None = None) → None

Add a triangle fan as indexed triangles.

The first vertex is the hub; triangles are formed with consecutive pairs of the remaining vertices.

generate_normals() → None

Auto-compute smooth normals from triangle geometry.

Only works when primitive type is TRIANGLES. Uses the index list if present, otherwise assumes every three consecutive vertices form a triangle.

generate_tangents() → None

Auto-compute tangents using Lengyel’s method (MikkTSpace-lite).

Stores tangent data on the resulting mesh as a tangents attribute (Nx4 float32 array with w = handedness). This is a best-effort implementation suitable for normal mapping.

commit() → simvx.core.graphics.mesh.Mesh

Build and return a Mesh from the accumulated vertex data.

clear() → None

Reset the tool for reuse (same as constructing a new instance).

property vertex_count: int

Number of vertices accumulated so far.

property index_count: int

Number of indices accumulated so far.

class simvx.core.mesh_builder.ImmediateGeometry3D(**kwargs)

Bases: simvx.core.nodes_3d.node3d.Node3D

A 3D node whose mesh is rebuilt every frame via a callback.

Override _draw_geometry or connect to the draw signal to provide geometry each frame. The node creates a fresh MeshBuilder, passes it to your callback, and commits the result as the renderable mesh.

Usage::

class MyTrail(ImmediateGeometry3D):
    def _draw_geometry(self, st: MeshBuilder) -> None:
        st.begin(PrimitiveType.TRIANGLES)
        # ... add vertices ...

Or with signals::

def draw_fn(st: MeshBuilder) -> None:
    st.begin(PrimitiveType.TRIANGLES)
    # ...

ig = ImmediateGeometry3D()
ig.draw.connect(draw_fn)

Initialization

on_update(dt: float) → None

position

‘_SpatialVecProperty(…)’

rotation

‘Property(…)’

scale

‘_SpatialVecProperty(…)’

render_layer

‘Property(…)’

property rotation_degrees: simvx.core.math.types.Vec3

property world_position: simvx.core.math.types.Vec3

property world_rotation: simvx.core.math.types.Quat

property world_scale: simvx.core.math.types.Vec3

property forward: simvx.core.math.types.Vec3

property right: simvx.core.math.types.Vec3

property up: simvx.core.math.types.Vec3

translate(offset: tuple[float, float, float] | numpy.ndarray)

translate_global(offset: tuple[float, float, float] | numpy.ndarray)

rotate(axis: tuple[float, float, float] | numpy.ndarray, angle: float)

rotate_x(angle: float)

rotate_y(angle: float)

rotate_z(angle: float)

look_at(target: tuple[float, float, float] | numpy.ndarray, up=None)

face_along(forward: tuple[float, float, float] | numpy.ndarray, up: tuple[float, float, float] | numpy.ndarray | None = None) → None

set_render_layer(index: int, enabled: bool = True) → None

is_on_render_layer(index: int) → bool

wrap_bounds(bounds: tuple[float, float, float] | numpy.ndarray, margin: float = 1.0)

strict_errors: ClassVar[bool]

True

dev_checks: ClassVar[bool]

None

dev_warnings: ClassVar[bool]

None

freeze_check_interval: ClassVar[float]

1.0

dynamic: bool

False

visible

‘Property(…)’

update_mode

‘Property(…)’

focus_mode

‘Property(…)’

drag_threshold

‘Property(…)’

focus_entered

‘Signal(…)’

focus_exited

‘Signal(…)’

__properties__: ClassVar[dict[str, simvx.core.descriptors.Property]]

None

classmethod __init_subclass__(**kwargs)

property name: str

property visible_in_tree: bool

property input_player: simvx.core.input.players.InputPlayer

property input_context: simvx.core.input.contexts.InputContext | None

reset_error() → None

add_child(node: simvx.core.node.T) → simvx.core.node.T

remove_child(node: simvx.core.node.Node) → None

reparent(new_parent: simvx.core.node.Node)

node_at(path, default=_NO_DEFAULT)

find(target, *, direct: bool = False)

find_all(target, *, direct: bool = False)

expect(target, *, direct: bool = False)

ancestor(target)

walk(*, include_self: bool = True) → collections.abc.Iterator[simvx.core.node.Node]

property path: str

property is_scene_root: bool

add_to_group(group: str)

remove_from_group(group: str)

is_in_group(group: str) → bool

on_ready() → None

on_enter_tree() → None

on_exit_tree() → None

on_fixed_update(dt: float) → None

on_draw(canvas) → None

on_draw_3d(gizmos) → None

on_picked(event: simvx.core.input.events.PickEvent) → bool | None

on_gui_input(event: simvx.core.input.events.GuiInputEvent) → bool | None

start_coroutine(gen: simvx.core.descriptors.Coroutine) → simvx.core.descriptors.CoroutineHandle

stop_coroutine(gen_or_handle)

property focused: bool

property focus_rect: tuple[float, float, float, float] | None

drag_threshold_for(pointer_type: simvx.core.input.enums.PointerType | str) → float

grab_focus() → None

release_focus() → None

capture_pointer(pointer_id: int | None = None) → None

release_pointer(pointer_id: int | None = None) → None

queue_redraw() → None

property render_dirty: bool

clear_children()

destroy()

property destroying: bool

property destroyed: bool

call_deferred(method: collections.abc.Callable[..., Any], *args: Any) → None

property app

property tree: simvx.core.scene_tree.SceneTree

property viewport_size: simvx.core.math.types.Vec2

property viewport_insets: tuple[float, float, float, float]

property physics

property physics_2d

__getitem__(key: str)

classmethod get_properties() → dict[str, simvx.core.descriptors.Property]

__repr__()