Legacy Field Layouts

This reference lists the serialized members of every pre-ZIP runtime class currently supported by skppy. Rows are in wire order. The class schema is written as v; version gates refer to that class unless a row says otherwise.

The tables describe bytes, not Python implementation attributes. A derived class starts with its serialized base-class body, so the base appears as the first member rather than duplicating the same rows in every derived table.

Type notation

Type	Wire representation
bool	One-byte archive boolean
u8, u16, u32, u64, i32	Little-endian integer of the stated width
sparse_u64	One presence-mask byte followed by the selected bytes of a u64
f32, f64	Little-endian IEEE-754 value
Point3, Vector3	Three f64 values
Plane4	Four f64 values
RGBA	Four bytes in red, green, blue, alpha order
GUID	16 uninterpreted bytes
legacy_string	Length-prefixed UTF-16 string described in legacy container
object<T>	Archive object tag followed by a body only when the tag introduces a new object
object_ref<T>	Archive object reference; null is allowed where the description says so
inline<T>	A serialized class body with no separate object tag at this position
counted<T>	u32 count followed by that many values
terminated<T>	Values ending with the terminator named in the description

Common bases and root model

CEntity

Member	Type	Description	Present when
legacy_flags	u32	Historical entity flags.	v == 1
attribute_container	object<CAttributeContainer>	Optional attributes owned by this entity.	v > 2
persistent_id	u64	Fixed-width persistent identifier.	v == 4
persistent_id	sparse_u64	Sparse persistent identifier.	v > 4

Schemas 0 and 2 have an empty body. In the SU3–8 maps, schema 2 is used by SU3 and schema 3 stores only the attribute-container member.

CDrawingElement

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
material	object_ref<CMaterial>	Front or primary display material; null means no material.	Always
hidden	bool	Element visibility flag.	v != 0
casts_shadows	bool	Whether the element casts shadows.	v > 5
receives_shadows	bool	Whether the element receives shadows.	v > 5
soft	bool	Soft-edge state.	v > 6
smooth	bool	Smooth-edge state.	v > 7
locked	bool	Lock state.	v > 8
obsolete_reference_present	bool	Announces a historical reference.	v == 2
obsolete_reference	object_ref<?>	Historical reference with no current public mapping.	v == 2 and preceding flag is true
layer	object_ref<CLayer>	Owning layer/tag reference.	v > 3

When schemas 0–5 omit the two shadow booleans, their decoded defaults are true. Older schemas also derive smooth state from the stored soft state.

CComponentBehavior

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
is_2d	bool	Whether placement is constrained to a plane. Older schemas imply true.	v >= 3
cuts_opening	bool	Whether placed instances cut an opening.	Always
snap_to	u32	Placement-plane mode. Schema 1 implies zero.	v >= 2
camera_flags	u8	Bit 0 faces the camera; bit 1 makes shadows face the sun.	v > 3
no_scale_mask	u32	Axes on which instance scaling is disabled.	v >= 5

CSketchUpModel

CSketchUpModel is the untagged root object. Its members include complete embedded class bodies and object-bearing sections; the referenced class tables define those bodies.

Member	Type	Description	Present when
prologue_word_1	u32	Confirmed root word whose semantics remain unnamed.	model v >= 7
prologue_word_2	u32	Second confirmed unnamed root word.	model v >= 7
license_product_family	u32	Product-family value recorded by the save target.	model v >= 18
next_persistent_id	u64	Next persistent entity identifier.	model v >= 26
thumbnail_dib	object<CDib>	Root thumbnail image object.	model v > 3
redefine_thumbnail_on_save	bool	Thumbnail regeneration state.	model v > 3
root_behavior	inline<CComponentBehavior>	Root component placement behavior.	Always
description	legacy_string	Model description.	Always
options	inline<COptionsManager>	Model option providers; older schemas place this in the tail.	model v >= 21
model_properties	object<CAttributeContainer>	Root attribute dictionaries.	model v >= 21
camera_leading_object	object<?>	Extra root-camera-section object, observed as null or CDib.	model v >= 21
camera	object<CCamera> or inline<old camera>	Root camera; model schemas below 11 use the older untagged body.	Always
rendering_options	inline<CRenderingOptions>	Root rendering state, including its CEntity base.	Always
obsolete_vertex_count	u32	Historical root vertex count.	Always
validity_check_performed	u32	Saved validity-check state.	model v >= 18
root_component	inline<CComponent>	Root materials, layers, definitions, and entities.	Always
shadow_info	inline<CShadowInfo>	Model shadow and geolocation state.	Always
pages	inline<CPageList>	Saved scenes; older schemas use an inline counted page array.	model v >= 12
legacy_pages	counted<object<CViewPage>>	Saved scenes before CPageList.	model v < 12
model_axes	inline<CSketchCS>	Model drawing axes, including the drawing-element base.	Always
state_words	u32[16]	Sixteen confirmed model-state words with no public semantic names.	Always
tail_options	inline<COptionsManager>	Model option providers at their older location.	model v < 21
dimension_style	inline<CDimensionStyle>	Default dimension style.	model v >= 8
text_style	inline<CTextStyle>	Default text style.	model v >= 10
fonts	inline<CFontManager>	Font registry.	Always
line_styles	inline<CLineStyleManager>	Custom line-style registry.	model v >= 29
background_image	object<CBackgroundImage>	Default model background image.	model v == 13 or v > 14
styles	inline<CSkpStyleManager>	Named style registry.	model v >= 14
watermarks	inline<CWatermarkManager>	Watermark registry.	model v >= 16
final_state	u32	Late model-state word.	model v >= 20
final_flag	bool	Late model-state flag.	model v >= 22

Attributes and technical face data

CAttribute

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
attribute_code	u32	Technical attribute discriminator/state value.	v == 0

CAttributeContainer

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
entries	terminated<object<CAttribute>>	Attribute objects, including named dictionaries and face UV data; a null object tag terminates the sequence.	v == 0

CAttributeNamed

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
prefix	u32	Technical dictionary prefix value.	Always
name	legacy_string	Dictionary name.	Always
entries	terminated<(legacy_string, CTypedValue)>	Key/value entries; an empty key terminates the sequence.	Always
suffix	u32	Technical dictionary suffix value.	v > 0

The field-body reader is also used for unregistered root dictionaries after their entity base has been consumed.

CFaceTextureCoords

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
attribute_flags	u32	Attribute-level texture-coordinate flags.	Always
front_transform	f64[9]	Homogeneous front-side UVQ transform.	Always
front_origin	Point3	Front projection origin or direction carrier.	v > 0
back_transform	f64[9]	Homogeneous back-side UVQ transform.	v > 1
back_origin	Point3	Back projection origin or direction carrier.	v > 1
front_pins	counted<(f64, f64, f64, f64)>	Front texture/model coordinate pin pairs.	v > 2
back_pins	counted<(f64, f64, f64, f64)>	Back texture/model coordinate pin pairs.	v > 2
front_flags	u32	Bit 0x01 enables the side and bit 0x02 selects stored projection direction.	v > 3
back_flags	u32	Back-side equivalent of front_flags.	v > 3

Geometry and construction

CVertex

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
position	Point3	Vertex position in model coordinates.	v == 0

CEdge

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Visibility, material, layer, and edge-state flags.	Always
start_vertex	object<CVertex>	Start vertex; SU3 may reuse the previous edge’s end through a chained edge reference.	Always
end_vertex	object<CVertex>	End vertex.	Always
curve	object<CCurve>	Optional owning curve.	v >= 2

CEdgeUse

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
edge	object_ref<CEdge>	Edge traversed by this loop use.	Always
reversed	bool	Reverses traversal relative to edge direction.	Always
loop	object_ref<CLoop>	Owning loop reference.	Always
obsolete_reference_1	object_ref<?>	Historical topology reference.	v == 0
obsolete_reference_2	object_ref<?>	Second historical topology reference.	v == 0

CLoop

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
is_outer	bool	Marks the outer face boundary.	Always
is_convex	bool	Cached convexity state.	Always
edge_uses	terminated<object<CEdgeUse>>	Directed boundary uses; a null object tag terminates the sequence.	Always

CFace

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Entity, front material, visibility, and layer state.	Always
plane	Plane4	Face plane equation.	Always
loops	counted<object<CLoop>>	Outer loop first, followed by inner loops.	Always
back_material	object_ref<CMaterial>	Optional back-side material.	v > 2

CCurve

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
first_edge	object_ref<CEdge>	First edge of the historical SU3 range representation.	v == 3
last_edge	object_ref<CEdge>	Last edge of the historical SU3 range representation.	v == 3
is_polygon	bool	Whether the curve is polygonal.	v in {3, 4}
edge_count	u32	Number of owned edges; concrete edge links are supplied by edge curve references.	v in {3, 4}

CArcCurve

Member	Type	Description	Present when
curve	inline<CCurve>	Shared curve base and edge ownership.	Always
center	Point3	Arc center.	v >= 1
normal	Vector3	Arc-plane normal.	v >= 1
x_axis	Vector3	Radius direction at zero angle.	v >= 1
start_angle	f64	Start parameter in radians.	v >= 1
end_angle	f64	End parameter in radians.	v >= 1
y_axis	Vector3	Second in-plane arc axis.	v >= 1

CConstructionGeometry

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Complete payload of this base-only construction entity.	v == 0

CConstructionPoint

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Visibility, material, and layer state.	Always
position	Point3	Guide point position.	v == 0
reference_position	Point3	Other endpoint of the optional guide segment.	v == 0
has_reference_position	bool	Whether reference_position is active.	v == 0

CConstructionLine

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Visibility, material, and layer state.	Always
origin	Point3	Point on the guide line.	Always
direction	Vector3	Guide direction.	Always
start_parameter	f64	Lower parametric bound.	v == 1 outside SU3
end_parameter	f64	Upper parametric bound.	v == 1 outside SU3
stipple_pattern	u32	Guide display pattern.	v == 1 outside SU3

CPolyline3d

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Visibility, material, and layer state.	Always
points	counted<Point3>	Ordered polyline positions.	v == 0

CSectionPlane

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Visibility, material, and layer state.	Always
plane	Plane4	Section plane equation.	v in {2, 3}
name	legacy_string	Section-plane display name.	v >= 3 and file target >= 18
symbol	legacy_string	Section-plane symbol.	v >= 3 and file target >= 18

Components and collections

CComponent

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Component-level entity, material, layer, and display state.	Always
materials	inline<CMaterialManager>	Materials scoped to this component.	v == 11
layers	inline<CLayerManager>	Layers and active layer scoped to this component.	v == 11
definitions	inline<CDefinitionList>	Nested component definitions.	v == 11
entities	counted<object<CEntity>>	Top-level component entities.	v == 11
relationships	counted<object<CRelationship>>	Graph bookkeeping relationships.	v == 11
active_section_plane	object<CSectionPlane>	Active section plane, optionally introduced inline.	v == 11

CComponentDefinition

Member	Type	Description	Present when
component	inline<CComponent>	Definition-owned materials, layers, definitions, entities, and relationships.	Always
guid	GUID	Stable definition identifier.	v in {10, 11}
name	legacy_string	Definition name.	v in {10, 11}
description	legacy_string	Definition description.	v in {10, 11}
loaded_from	legacy_string	Informational source path; consumers must not follow it.	v in {10, 11}
timestamp	u32	Saved source timestamp.	v in {10, 11}
modified	bool	Modification state.	v in {10, 11}
insertion_point	Point3	Definition insertion point.	v in {10, 11}
behavior	inline<CComponentBehavior>	Placement, opening, billboard, and scale behavior.	v in {10, 11}
definition_type	u32	Definition category; confirmed values identify ordinary, group, and image definitions.	v in {10, 11}
thumbnail	object<CThumbnail>	Optional definition preview.	v in {10, 11}

CComponentInstance

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Entity, material, visibility, and layer state.	Always
definition	object<CComponentDefinition>	Referenced definition.	Always
transform	f64[13]	Legacy component placement transform.	Always
name	legacy_string	Optional instance name.	v > 3
guid	GUID	Instance GUID.	v >= 5

CGroup

Member	Type	Description	Present when
component_instance	inline<CComponentInstance>	Complete placed-component body interpreted as a group.	v == 1

CImage

Member	Type	Description	Present when
component_instance	inline<CComponentInstance>	Complete placed-component body interpreted as an image placement.	v == 1

CDefinitionList

Member	Type	Description	Present when
definitions	counted<object<CComponentDefinition>>	Definition references; a first occurrence may introduce the full object inline.	v == 0

CRelationship

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
source	object_ref<CEntity>	Relationship source.	v == 0
target	object_ref<CEntity>	Relationship target.	v == 0

CRelationshipMap

Member	Type	Description	Present when
relationships	counted<object<CRelationship>>	Relationship objects retained as valid source/target pairs.	v == 0

Materials, images, layers, and line styles

CMaterial

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
name	legacy_string	Material name.	v == 12
has_texture	bool	Announces the inline texture body.	v == 12
texture	inline<CTexture>	Optional texture and embedded image.	v == 12 and preceding flag is true
used_by_layer	bool	Whether this material is layer display state.	v == 12
color	RGBA	Base display color.	v == 12
display_name	legacy_string	Additional saved material string.	v == 12
material_type	u32	Material category.	v == 12
colorize_type	u32	Texture colorization mode.	v == 12
transparency	f64	Transparency amount, not opacity.	v == 12
use_transparency	bool	Enables the transparency scalar.	v == 12

When transparency is enabled, public opacity is clamp(1 - transparency); otherwise opacity is 1.0.

CMaterialManager

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
materials	counted<object<CMaterial>>	Material registry in archive order.	Always
current_material	object_ref<CMaterial>	Runtime selection state, not a separate public material.	v >= 2

CTexture

Member	Type	Description	Present when
has_inline_dib	bool	Announces an untagged CDib body in older layouts.	v < 5
inline_dib	inline<CDib>	Older embedded image body.	v < 5 and preceding flag is true
entity	inline<CEntity>	Common entity state in newer layouts.	v >= 5
dib	object<CDib>	Embedded image object.	v >= 5
width	f64	Physical texture width in model inches.	Always
height	f64	Physical texture height in model inches.	Always
filename	legacy_string	Informational texture filename.	Always
average_color	RGBA	Saved average image color.	Always

CDib

Member	Type	Description	Present when
image_format	u32	Encoded-image format. Schema 1 implies value 4 without storing it.	v > 1
byte_count	u32	Length of encoded image data.	v > 0
image_bytes	u8[byte_count]	Bounded PNG, JPEG, BMP, or related encoded bytes.	v > 0
format_1_suffix	u32	Extra format-specific word.	v >= 3 and image_format == 1

Schema 0 has an empty body.

CThumbnail

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
camera	inline<old camera>	Untagged historical camera payload.	v == 0
camera	object<CCamera>	Camera associated with the thumbnail.	v == 1
dib	object<CDib>	Thumbnail image bytes.	v in {0, 1}

CLayer

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
name	legacy_string	Layer/tag name.	Always
hidden	bool	Stored inverse of public visibility.	Always
display_material	inline<CMaterial>	Layer display material; it is not added to the model material registry.	Always
page_behavior	u32	Per-scene visibility behavior.	v > 1
obsolete_reference	object_ref<?>	Historical layer reference with no current public mapping.	v > 2

CLayerManager

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
layers	counted<object<CLayer>>	Layer registry.	Always
active_layer	object_ref<CLayer>	Active layer.	v == 3 or layer count is nonzero
folders	counted<object<CLayerGroup>>	Flat folder list used by the first folder layout.	v == 6
root_folder	inline<CLayerGroup>	Root of the nested folder tree.	v >= 7

CLayerGroup

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
name	legacy_string	Folder name.	v in {1, 2, 3}
child_folders	counted<object<CLayerGroup>>	Nested folders.	v in {1, 2, 3}
child_layers	counted<object_ref<CLayer>>	Layers directly owned by the folder.	v in {1, 2, 3}
visible	bool	Folder visibility.	v > 1
expanded	bool	Saved user-interface expansion state.	v > 2

CCustomLineStyle

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
historical_entity	inline<CEntity>	Second historical entity body.	v < 3
name	legacy_string	Line-style name.	v in {1, 2, 3, 4}
dash_code	u16	Numeric dash pattern.	v == 1
dash_pattern	legacy_string	Text dash pattern.	v > 1
line_width_points	f64	Display width in points.	Always
stipple_scale	f64	Dash-pattern scale.	v > 1
superseded_width	f64	Historical width value retained for alignment.	v in {2, 3}
color	u32	Packed line color.	v >= 4
mutable	u8	Whether the style can be edited.	v >= 4

Cameras, pages, and visual metadata

CCamera

Member	Type	Description	Present when
eye	Point3	Camera position.	Always
target	Point3	Look-at target.	Always
up	Vector3	Up direction.	Always
near	f64	Near clipping distance.	Always
far	f64	Far clipping distance.	Always
perspective	bool	Perspective rather than orthographic projection.	Always
field_of_view	f64	Perspective field of view.	Always
orthographic_height	f64	Orthographic view height.	Always
obsolete_vector	Vector3	Historical vector retained for alignment.	Always
aspect_ratio	f64	Image aspect ratio.	Always
fov_is_height	bool	Whether field of view is measured vertically.	Always
legacy_flag	bool	Confirmed camera flag whose semantics remain unnamed.	v >= 2
name	legacy_string	Camera name.	v > 2
image_width	f64	Saved image-plane width.	v > 3
is_2d	bool	Two-dimensional camera mode.	v > 4
scale_2d	f64	Two-dimensional view scale.	v > 4
center_2d_x	f64	Two-dimensional image center X.	v > 4
center_2d_y	f64	Two-dimensional image center Y.	v > 4

The untagged SU3 camera replaces target with a direction vector and ends after the obsolete vector; the public target is reconstructed as eye + direction.

CSketchUpPage

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
name	legacy_string	Scene/page name.	v == 1
description	legacy_string	Scene/page description.	v == 1

CViewPage

Member	Type	Description	Present when
page	inline<CSketchUpPage>	Entity base, page name, and description.	Always
flags	u32	Snapshot-presence mask: camera, rendering, shadows, axes, hidden entities, layer visibility, and sections.	Always
camera	inline<old camera> or object<CCamera>	Camera snapshot; untagged before page schema 7.	camera bit set
rendering_options	inline<CRenderingOptions>	Rendering snapshot, including its entity base.	rendering bit set
style	object_ref<CSkpStyle>	Style used by the rendering snapshot.	rendering bit set and v > 9
shadow_info	inline<CShadowInfo>	Shadow snapshot.	shadow bit set
display_shadows	bool	Scene-local shadow visibility.	shadow bit set
axes	inline<CSketchCS>	Axes snapshot.	axes bit set
display_axes	bool	Scene-local axes visibility.	axes bit set
hidden_entities	counted<object_ref<CEntity>>	Hidden entity set.	hidden bit set
hidden_layers	counted<object_ref<CLayer>>	Layer-visibility override set.	layer-visibility bit set
active_section_planes	counted<object_ref<CSectionPlane>>	Active section-plane set.	section bit set
show_in_slideshow	bool	Include page in scene animation.	Always
display_watermarks	bool	Historical page-level watermark state.	6 <= v <= 10
transition_time	f64	Transition duration.	v >= 8
delay_time	f64	Pause duration.	v >= 9
background_image	object<CBackgroundImage>	Optional page background image.	v > 9
display_background_image	bool	Scene-local background-image visibility.	v >= 12
image_rep_present	bool	Announces an embedded ImageFileRep.	v >= 12
image_rep	inline<ImageFileRep>	Optional saved image representation.	v >= 12 and preceding flag is true

CPageList

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
pages	counted<object<CViewPage>>	Saved pages in display order.	v == 1
active_page	object_ref<CViewPage>	Runtime active-page selection.	v == 1

CBackgroundImage

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
image_reference	inline<ImageReference>	Image path, data, dimensions, and saved file state.	v == 10
visible	bool	Background-image visibility.	v == 10
opacity	f64	Background-image opacity.	v == 10
grip_points	counted<Point3>	Calibration/control points.	v == 10
principal_point_delta	Vector3	Photo-match principal-point offset.	v == 10
radial_distortion_k1	f64	First radial lens-distortion coefficient.	v == 10
image_source	u32	Saved image-source category.	v == 10

CSketchCS

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Present when the axes object is read from the archive graph.	Always
origin	Point3	Axes origin.	v == 0
x_axis	Vector3	X-axis direction.	v == 0
y_axis	Vector3	Y-axis direction.	v == 0
z_axis	Vector3	Z-axis direction.	v == 0

The root-model axes body follows an already consumed drawing-element prefix; the four geometric members above are the CSketchCS field body.

CShadowInfo

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
time	u32	Saved shadow time value.	v == 7
daylight_savings	bool	Daylight-saving adjustment.	v == 7
country	legacy_string	Geolocation country.	v == 7
city	legacy_string	Geolocation city.	v == 7
longitude	f64	Longitude in degrees.	v == 7
latitude	f64	Latitude in degrees.	v == 7
timezone_offset	f64	Time-zone offset.	v == 7
north_direction	Vector3	Model north direction.	v == 7
display_shadows	bool	Master shadow visibility.	v == 7
display_north	bool	North-indicator visibility.	v == 7
display_on_all_faces	bool	Draw shadows on all faces.	v == 7
display_on_ground_plane	bool	Draw shadows on the ground plane.	v == 7
light	i32	Light intensity setting.	v == 7
dark	i32	Dark intensity setting.	v == 7
use_sun_for_all_shading	bool	Use sun direction for all face shading.	v == 7

CWatermark

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
leading_flag	bool	Confirmed watermark flag with no public semantic name.	v == 1
name	legacy_string	Watermark name.	v == 1
state_word	u32	Confirmed saved state word.	v == 1
position	u32	Watermark placement mode.	v == 1
state_flag_1	bool	First saved placement/display flag.	v == 1
state_flag_2	bool	Second saved placement/display flag.	v == 1
state_flag_3	bool	Third saved placement/display flag.	v == 1
state_flag_4	bool	Fourth saved placement/display flag.	v == 1
state_flag_5	bool	Fifth saved placement/display flag.	v == 1
scale	f64	Saved watermark scale value.	v == 1
opacity	f64	Watermark opacity.	v == 1
path	legacy_string	Informational source path.	v == 1
dib	object<CDib>	Encoded watermark image.	v == 1

CWatermarkManager

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
watermarks	counted<object<CWatermark>>	Watermark registry.	v == 2

Annotations, fonts, and styles

CDimension

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Entity, material, visibility, and layer state.	Always
text	legacy_string	Dimension text.	Always
font	object<CSkFont>	Dimension font.	v >= 1
is_3d_text	bool	Whether text is placed in model space.	v >= 1
arrow_type	u32	Dimension arrowhead type.	v >= 1

CDimensionLinear

Member	Type	Description	Present when
dimension	inline<CDimension>	Common dimension text, font, and drawing state.	Always
start_ref	inline<CPointRef>	First measured anchor.	Always
end_ref	inline<CPointRef>	Second measured anchor.	Always
normal	Vector3	Dimension-plane normal.	Always
x_axis	Vector3	Dimension local X direction.	Always
dimension_type	u32	Linear dimension layout type.	Always
y_position	f64	Text/line position on the local Y axis.	Always
x_position	f64	Text/line position on the local X axis.	Always
text_position	u32	Explicit text-position mode; older schemas imply zero.	v > 5

CDimensionRadial

Member	Type	Description	Present when
dimension	inline<CDimension>	Common dimension text, font, and drawing state.	Always
target	object_ref<CEdge>	Referenced arc edge; null selects embedded arc geometry.	v == 2
parameter	f64	Parameter on the target arc.	v == 2
radius_ratio	f64	Radial leader placement ratio.	v == 2
is_diameter	bool	Diameter rather than radius annotation.	v == 2
arc	inline<CArc3d>	Fallback arc when target is null.	v == 2 and target is null

CText

Member	Type	Description	Present when
drawing_element	inline<CDrawingElement>	Entity, material, visibility, and layer state.	Always
font	object<CSkFont>	Text font.	v == 9
screen_x	f64	Saved horizontal screen offset.	v == 9
screen_y	f64	Saved vertical screen offset.	v == 9
point_ref	inline<CPointRef>	Anchor entity, point, and instance paths.	v == 9
leader_vector	Vector3	Leader direction/offset.	v == 9
view_direction	Vector3	View direction used for placement.	v == 9
leader_type	u32	Leader layout type.	v == 9
line_weight	u32	Leader line weight.	v == 9
point_ref_front	bool	Front-side anchor state.	v == 9
hide_out_of_plane	bool	Hide when viewed out of plane.	v == 9
arrow_type	u32	Leader arrowhead type.	v == 9
display_leader	bool	Leader visibility.	v == 9
text	legacy_string	Annotation text.	v == 9
convert_to_screen_on_explode	bool	Conversion behavior when exploding its owner.	v == 9
hidden_leader_direction	u32	Saved direction for a hidden leader.	v == 9

CSkFont

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
face_name	legacy_string	Typeface family name.	v in {0, 1}
bold	bool	Bold style.	v in {0, 1}
italic	bool	Italic style.	v in {0, 1}
point_size	u32	Screen size in points.	v in {0, 1}
use_world_size	bool	Enables model-space font sizing.	v > 0
world_size	f64	Model-space text height.	v > 0

CFontManager

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
fonts	counted<object<CSkFont>>	Font registry.	v == 0

CTextStyle

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
font	object_ref<CSkFont>	Primary/world font.	v in {4, 5}
arrow_type	u32	Leader arrowhead type.	v in {4, 5}
line_weight	u32	Leader line weight.	v in {4, 5}
hide_out_of_plane	bool	Hide out-of-plane text.	v in {4, 5}
leader_type	u32	Leader layout type.	v in {4, 5}
display_leader	bool	Default leader visibility.	v in {4, 5}
color	RGBA	Model-space text color.	v in {4, 5}
screen_color	RGBA	Screen-space text color; schema 4 reuses color.	v > 4
screen_font	object_ref<CSkFont>	Screen-space font; schema 4 reuses font.	v > 4

CDimensionStyle

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
style_version	u32	Saved style serialization word.	v == 4
font	object_ref<CSkFont>	Dimension font.	v == 4
text_3d	bool	Place text in model space.	v == 4
always_readable	bool	Keep text readable from either view side.	v == 4
extension_offset	u32	Extension-line offset.	v == 4
extension_overshoot	u32	Extension-line overshoot.	v == 4
line_weight	u32	Dimension line weight.	v == 4
arrow_type	u32	Arrowhead type.	v == 4
arrow_size	u32	Arrowhead size.	v == 4
highlight_non_associative	bool	Highlight dimensions detached from geometry.	v == 4
highlight_color	RGBA	Detached-dimension highlight color.	v == 4
show_radial_diameter_prefix	bool	Show radius/diameter prefix.	v == 4
hide_out_of_plane	bool	Hide out-of-plane dimensions.	v == 4
hide_out_of_plane_value	f64	Out-of-plane threshold.	v == 4
hide_small	bool	Hide dimensions below a size threshold.	v == 4
hide_small_value	f64	Small-dimension threshold.	v == 4
color	RGBA	Dimension line color.	v == 4
text_color	RGBA	Dimension text color.	v == 4
text_position	u32	Default text-position mode.	v == 4

CSkpStyle

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
guid	GUID	Style identifier.	v in {1, 2}
initial_file_name	legacy_string	Original style filename.	v in {1, 2}
style_version	u32	Version of the style option stream.	v in {1, 2}
display_name	legacy_string	User-facing style name.	v in {1, 2}
file_name	legacy_string	Current style filename.	v in {1, 2}
options	counted<(u32 key, style variant)>	Heterogeneous style options; object-bearing NPR and watermark values retain archive references.	v in {1, 2}

CSkpStyleManager

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
styles	counted<object<CSkpStyle>>	Named styles.	v == 2
active_style	object_ref<CSkpStyle>	Active style.	v == 2 and count is nonzero
selected_style	object_ref<CSkpStyle>	Selected style.	v == 2 and count is nonzero
selected_style_dirty	bool	Whether the selected style has unsaved changes.	v == 2 and count is nonzero

Rendering options

CRenderingOptions

The root and scene forms consume the same entity body immediately before the following ordered members.

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
render_mode	u32	Face rendering mode.	Always
model_transparency	bool	Model-level transparency display.	Always
material_transparency	bool	Material transparency display.	Always
jitter_edges	bool	Jittered edge display.	Always
line_style_edges	bool	Custom line-style edge display; older schemas imply true.	v > 37
edge_display_mode	u32	Edge visibility mode.	Always
background_color	RGBA	View background color.	Always
foreground_color	RGBA	Foreground/edge color.	Always
highlight_color	RGBA	Selection highlight color.	Always
construction_color	RGBA	Construction-geometry color.	Always
obsolete_display_flag	bool	Historical display flag with intentionally unnamed semantics.	Always
display_instance_axes	bool	Component-instance axes visibility.	Always
display_color_by_layer	bool	Color geometry by layer.	Always
texture	bool	Texture display.	Always
edge_color_mode	u32	Edge color source.	Always
extend_lines	bool	Extend edge endpoints.	Always
line_extension	u32	Extension length.	Always
draw_silhouettes	bool	Silhouette edge display.	Always
silhouette_width	u32	Silhouette width.	Always
draw_depth_que	bool	Depth-cued edge display.	v >= 26
depth_que_width	u32	Depth-cue width.	v >= 26
draw_line_ends	bool	Line-end display.	v >= 26
line_end_width	u32	Line-end width.	v >= 26
draw_profiles_only	bool	Restrict profile processing to profiles.	v >= 28
draw_hidden_geometry	bool	Hidden geometry visibility.	Always
draw_hidden_objects	bool	Hidden object visibility; older schemas reuse hidden geometry.	v >= 39
face_color_mode	u32	Face color source/mode.	Always
face_front_color	RGBA	Default front-face color.	Always
face_back_color	RGBA	Default back-face color.	Always
inactive_fade	f64	Fade amount for inactive geometry.	Always
instance_fade	f64	Fade amount for other component instances.	Always
inactive_hidden	bool	Hide inactive geometry.	Always
instance_hidden	bool	Hide other component instances.	Always
display_fog	bool	Fog visibility.	v >= 29
fog_color	RGBA	Fog color.	v >= 29
fog_use_background_color	bool	Use background color for fog.	v >= 29
fog_start_dist	f64	Fog start distance.	v >= 29
fog_end_dist	f64	Fog end distance.	v >= 29
fog_hint_mode	u32	Fog distance interpretation.	v >= 30
edge_type	u32	Edge rendering type.	v > 30
display_sketch_axes	bool	Model axes visibility.	v > 30
display_text	bool	Text visibility.	v > 30
display_dims	bool	Dimension visibility.	v > 30
hide_construction_geometry	bool	Hide guides and construction points.	v > 30
sky_color	RGBA	Sky color.	Always
horizon_color	RGBA	Horizon color.	v >= 24
ground_color	RGBA	Ground color.	Always
draw_horizon	bool	Horizon visibility.	Always
draw_ground	bool	Ground visibility.	Always
draw_underground	bool	Ground display below the horizon.	Always
ground_transparency	u32	Ground transparency.	Always
section_active_color	RGBA	Active section-plane color.	Always
section_inactive_color	RGBA	Inactive section-plane color.	Always
section_default_cut_color	RGBA	Default section-cut color.	Always
section_cut_width	u32	Section-cut line width.	Always
section_display_mode	u32	Bit 0x01 displays planes; bit 0x02 displays cuts.	Always
section_default_fill_color	RGBA	Default section-fill color.	v > 36
section_cut_filled	bool	Section fill visibility.	v > 36
transparency_sort	u32	Transparency sorting mode.	Always
draw_soft_edges	bool	Soft-edge display.	Always
soft_edge_limit	f64	Smoothing angle/limit.	Always
draw_smooth_edges	bool	Smooth-edge display.	Always
mipmap_option	bool	Historical model-level mipmap option.	v in {23, 24, 33}
locked_color	RGBA	Locked-entity display color.	v >= 27
display_watermarks	bool	Watermark visibility.	v >= 32
xray_opacity	f64	X-ray opacity.	v >= 35
draw_back_edges	bool	Back-edge display.	v >= 36
photomatch_draw_background	bool	Photo-match background visibility.	v >= 36
photomatch_background_opacity	f64	Photo-match background opacity.	v >= 36
photomatch_draw_overlay	bool	Photo-match overlay visibility.	v >= 36
photomatch_overlay_opacity	f64	Photo-match overlay opacity.	v >= 36

Confirmed complete schemas are 22, 25, 28, 32, and 35–39. Intermediate gate numbers explain field evolution but are not all known as complete emitted layouts.

Embedded serialization records

These records are not independent entries in the SU8 version map, but named class-like payloads occur inside the supported runtime classes above.

CPointRef

Member	Type	Description	Present when
kind	u32	Point-reference kind.	Always
format_version	u32	Selects the optional reference/path members.	Always
position	Point3	Saved point position.	Always
leaf	object<CEntity>	Referenced leaf entity.	Always
secondary_leaf	object<CEntity>	Optional second leaf.	format version > 0
instance_path	counted<object<CComponentInstance>>	Primary nested-instance path.	Always
secondary_instance_path	counted<object<CComponentInstance>>	Secondary nested-instance path.	format version > 3

CArc3d

Member	Type	Description	Present when
center	Point3	Arc center.	Always
normal	Vector3	Arc-plane normal.	Always
x_axis	Vector3	First in-plane axis.	Always
start_angle	f64	Start angle.	Always
end_angle	f64	End angle.	Always
y_axis	Vector3	Second in-plane axis.	Owning layout requests it

CTypedValue

Member	Type	Description	Present when
type_code	u8	Selects the following payload representation.	Always
value	Type selected by type_code	Null (0); integers (2–4, 8, 9); f32 (5); f64/time-like values (6, 12–16); bool (7); string (10); nested array (11); triples (17–19); or 16-double transform (20).	Type is not null

COptionsManager

Member	Type	Description	Present when
version	u32	Options-manager serialization version.	Always
providers	counted<option provider>	Named option-provider records.	Always
provider.name	legacy_string	Provider name.	For each provider
provider.entries	terminated<(legacy_string, CTypedValue)>	Option name/value pairs; an empty name terminates the provider.	For each provider

CLineStyleManager

Member	Type	Description	Present when
entity	inline<CEntity>	Common entity state.	Always
styles	counted<object<CCustomLineStyle>>	Custom line-style registry.	Always

ImageReference

Member	Type	Description	Present when
path	legacy_string	Informational image path.	v == 3
state	u32	Saved image-reference state.	v == 3
dib	object<CDib>	Encoded image data.	v == 3
width	u32	Pixel width.	v == 3
height	u32	Pixel height.	v == 3
file_size	u32	Saved source-file size.	v == 3
timestamp	u32	Saved source-file timestamp.	v == 3

ImageFileRep

Member	Type	Description	Present when
has_data	bool	Announces an encoded byte payload.	Always
byte_count	u32	Encoded payload length.	has_data is true
image_bytes	u8[byte_count]	Bounded image-representation bytes.	has_data is true

Deliberately neutral names

Fields whose behavior is not established by controlled fixtures retain names such as state_word, obsolete_*, or legacy_flag. This keeps byte order and type information explicit without assigning unsupported semantics.