OSM-4D/Roof table

This page was created by: Marek Strassenburg Kleciak, Kendzi

Note: This page is under construction! The definitions are constantly updated. As this page has gotten very long, the subtypes may be broken out into separate pages.

This page collects a list of 3D roof forms and is the part of OSM-4D-definition and as this part of the 3D building-definition.

The 3D roof forms are currently supported (visualization) by JOSM PlugIn Kendzi3D.

"Implemented:<Yes/no/soon>" means implementation in Kendzi 3D plugIn.

NOTE: For the correct application of this schema, the building should be marked tag roof:shape=3dr

Note

The total building height (H) is the same as defined in the specification S3DB.

This parameter is not included in the description below (Parameters), because it applies to all roof shapes.

Flat roofs

3D View / Top view + Sideviews
Numeric Type (3dr)	0.0	0.1	0.2	0.3	0.4
Human-friendly Type	flat	flat_with_terrace	flat_with_two_terraces	flat_with_three_terraces	flat_with_four_terraces
Parameters	height=*	H, H1, L1	H, H1, L1, L2 *.a	H, H1, L1, L2, L3 *.a	H, H1, L1, L2, L3, L4 *.a
Restrictions	none	L1< depth	L1< depth, L2< width	L1< depth, L2+L3< width	L1+L4< depth, L2+L3< width
Implemented	yes	yes	yes	yes	yes
Tagging	3dr:type=0.0 H - height=* <Value in meters> The highest measurable facade height from the top of the terrain to the top of the building wall, without chimneys, antennas, or skylights	3dr: type=0.1 H: height=* <Total height in meters> H1: 3dr:height1=<height of the projection> L1: 3dr:length1=<width of the first terrace>	3dr: type=0.2 H: height=* <Total height in meters> H1: 3dr:height1=<height of the projection> L1: 3dr:length1=<width of the first terrace> L2: 3dr:length2=<width of the second terrace>	3dr: type=0.3 H: height=* <Total height in meters> H1: 3dr:height1=<height of the projection> L1: 3dr:length1=<width of the first terrace> L2: 3dr:length2=<width of the second terrace> L3: 3dr:length3=<width of the third terrace>	3dr: type=0.4 H: height=* <Total height in meters> H1: 3dr:height1=<height of the projection> L1: 3dr:length1=<width of the first terrace> L2: 3dr:length2=<width of the second terrace> L3: 3dr:length3=<width of the third terrace> L3: 3dr:length3=<width of the fourth terrace>
Comment	Applies to all floor plans, including courtyards	Applies to all floor plans, including courtyards	Applies to all floor plans, including courtyards	Applies to all floor plans, including courtyards With L2 of 0, the result is as follows:	Applies to all floor plans, including courtyards

(*a) = if only L1 then all other L parameters = L1

Flat roofs with structures: other notes

Top view: Behavior of roof type 0.2 with an irregular square

The starting point S where the outline begins, and the direction of the building outline, determine how the roof is interpreted in 3D:

Outline drawn counterclockwise	Outline drawn clockwise

Outline of an irregular quadrilateral:

Top view: Behavior of the roof type 0.3 as an irregular quadrilateral.

Omitting a parameter on any layout

Top view: Behavior of the roof type 0.3 if the parameter L2 is not entered.

Concave floor plan:

Roofs with one sloping face

3D View / Top view + Sideviews
Typ	1.0	1.1
OSM tagging value	skillion	skillion_diagonal
Parameters	H1	H1, H2 *a
Restrictions	none	none
Implemented	yes	yes
Comment	Note starting point and direction	Note starting point and direction

Roof direction is defined by the first point drawn and direction of the outline. The first two points drawn are the lowest points on the roof. The angle of roof inclination is perpendicular to the first two drawn points and goes to the top.

Note: This is the definition specified by this page, some renderers may use other definitions. Please check the results of other definitions such as Kendzi3D.

Attention: H1 means still the difference between height=* and roof:height=* !

see Simple 3D Building: [1]

(*a) = No H3 required, as it can be derived from H1 and H2 given that the roof is flat

Roofs with 2 faces

3D View / Top view + Sideviews
Type	2.0	2.1	2.2	2.3	2.4
OSM tagging value	gabled	gabled_height_moved	side_hipped	half-hipped	hipped
Parameters	H1, L1 *a	H1, H2, L1 *a	H1, L1, L2 *a, *b, roof:orientation=<north, east, south, west, north_east, south_east, south_west, north_west> this example is roof:orientation=south	H1, H2, L1 *c	H1, L1, L2, L3 *a,*b,*d
Restrictions	L1<depth	L1<depth, H2>H1	L1<depth	L1<depth	L1<depth
Implemented	yes	yes	yes	yes	yes

(*a) = if no L1 then symmetry: 2xL1 = width

(*b) = if no L2 then symmetry: L2=L1

(*c) = if only H1 then H2 = 0.5xH1 , L1=0.5 x width

(*d) = if no L3 then L3=L2

Note: How to tag roof:orientation for roof:shape=side_hipped and similar roof shapes?

This should be self explaining: , , ,

This tag should be added for roof shapes:

• flat_double_terraced
• flat_triple_terraced
• skillion_diagonally
• side_hipped
• double_skillion
• triple_skillion
• corner_saltbox
• triple_saltbox
• round_skillion_cutted
• round_skillion_double_cutted

3D View / Top view + Sideviews			(image has mix l1 and l2)
Type	2.5	2.6	2.7	2.8	2.8 (subform)
OSM tagging value	pyramidal	double_skillion	triple_skillion	diagonal_pass	diagonal_pass
Parameters	H1, L1, L2 *a	H1, L1 *b	H1, L1, L2 *c , roof:orientation=<north, east, south, west, north_east, south_east, south_west, north_west> this example is roof:orientation=east	H1, H2, H3 *d	H1, H2, H3 *e
Restrictions	none	L1>0, L1<building width *a	L1>0, L1<building width, L2>0, L2<building width, L1+L2<building width *a, *b	H1, H2, L1 *c	H1, L1, L2, L3 *a,*b,*d
Implemented

(*a) = if no L1 then symmetry: 2xL1 = width, if no L1, L2 then symmetry: 2xL1 = width, 2xL2 = depth

(*b) = if no L1 then L1 = width

(*c) = if no L1,L2 then L1 = L2 = width. If L1+L2> depth then L1=L2=0.5 x depth

(*d) = Only three heights neccesary because the lowest height H, is the defined facade height.. H>H1 and H2>H3

(*e) = Possible subtype when H<H1 and H2<H3

Roofs with 2 Faces. L and T type

Buildings on the corner of 2 streets in the closed row of houses have often gabled roof shape which is difficult to generate only by use of roof:shape=gabled.

For this geoemtry I suggest the description roof:shape=L_gabled See example:

Roofs with more sloped faces

Subtype 3

3D View / Top view + Sideviews
Type	3.0	3.1	3.2	3.3	3.4
OSM tagging value	saltbox	double_saltbox	corner_saltbox	triple_saltbox	quadruple_saltbox
Parameters	H1, H2, L1	H1, H2, L1, L2	H1, L1, L2	H1, L1, L2, L3	H1, L1, L2, L3, L4
Implemented

Examples: 3.0 basic. 3.0 free outline.

Subtype 4

3D View / Top view + Sideviews							soon	soon
Typ	4.0	4.1	4.2	4.2.1 (L5<0)	4.2.1 (L5>0)	4.3	4.4	4.5
Typ	gambrel	mansard_onesided	mansard	thai_cutted	thai	pyramidal_diagonal	skillion_windmill	double_gabled
Parameters	H1, L1, L2, L3	H1, L2, L2, L3	H1, H2, L1, L2, L3, L4*	H1, H2, H3, L1, L2, L3, L4, L5	H1, H2, H3, L1, L2, L3, L4, L5	H1, H2	H1	H1, H2, H3
Restrictions
Implemented

(*) If symmetric, then only L1, L2 necessary

Type 4.2 has, depending on the values ​​of the parameters, sub forms which are not "mansard" roof:

Side view:

Side view:

Subtype 5

3D View / Top view + Sideviews
Typ	5.0	5.1	5.2	5.3	5.4	5.5	5.6	5.7	5.8
OSM tagging value	round	round_pyramidal	round_skillion	round_gabled	round_skillion_cutted	round_skillion_double_cutted	round_hipped	dome	dome_overlapped
Parameters	H1	H1	H1		H1, L1	H1, L1, L2	H1, L1, L2	H1	H1 *
Restrictions	H1 < depth / 2				L1<width	L1+L2<width	L1+L2<width	H1≤0,5*depth	H1≤0,5*depth
Implemented	yes

• Valid only for rectangular shapes!

Subtype 6

3D View / Top view + Sideviews
Typ	6.0	6.1	6.2	6.3	6.4
OSM tagging value	basilical		cross_gabled	basilical_five_aisled	apse_gabled
Paramaters	H1, H2, H3, L1	H1, H2, H3, H4, H5, H6, H7	H1	H1, H2, H3, H4, H5	H1, n
Description	3x nave Basilika		Building on the cross floor plan, Wings can have different lengths, Nave and transept must be continuously and they must each have the same width.	five-aisled basilica.	Building with an apsis Values: 0-semicircle, 2 to 9 indicates resolution of the half circle. Here=4
Restrictions
Implemented

Subtype 7

This subtype describes roofs with repeatable geometry. There are at the moment 5 repeatable geometries.

• Simple saw form
• Trapezoidal shape
• Double inclined saw form
• Semicircle
• Wave

The last, 3. number below "n" describes the number of repeat.

3D View / Top view + Sideviews	7.1.2	7.1.4 7.1.19	7.2.2 7.2.3	7.3.5	7.4.5 7.4.3	7.5.2
Type	7.1.n	7.1.n (subtype)	7.2.n	7.3.n	7.4.n	7.5.n
OSM tagging value	sawtooth		trapeze	gabled_row	round_row	wave
Parameters	H1	H1,n	H1,n	H1,n	H1,n	H1,n
Restrictions
Implemented

Inversion and half end

Syntax 7.m.n,5 means the half end of the "wave"

Syntax 7.m.ni mirrors the shape

Subtype 8

Subtype 8 describes

8.A

Rotation bodies based on round / regular polygonal ground view. In the default visualization the circle is divided into 24 segments.

3D View / Top view + Sideviews
Typ	8.0.1	8.0.2	8.0.3	8.0.4	8.0.n
OSM tagging value	cone	mansard_cone	double_mansard_cone	triple_mansard_cone	onion
Parameters	H1, D1	H1,H2,D1, D2	H1,H2,H3,D1, D2, D3	H1,H2,H3,H4,L2,L3,L4	Sehe Beispiel oben: Querschnitt
Description	Ebener Verlauf (Kegeldach)	1 x Knick in dem Dachflächenverlauf	2 x Knicks in dem Dachflächenverlauf [2]	3 x Knicks in dem Dachflächenverlauf	n x Knicks in dem Dachflächenverlauf z.B Zwiebelkuppel
Restrictions
Implemented

8.B

Surfaces of higher degrees

3D View / Top view + Sideviews		..
Type	8.1	8.2	8.3	8.4	8.5	8.6	8.7	8.8	8.9
OSM tagging value	hyperbolic_paraboloid	parabolic	hyperbolic_tower	elliptic_hyperboloid	ellipsoid_cutted	elliptic_paraboloid	tent	geodesic_dome	spherical_cutted
Parameters	H1,H2,H3	H1,H2,L1,L2,ResolutionH, ResolutionV	H1,D1, Twist, ResolutionH, ResolutionV	H1,D1,D2,ResolutionH, ResolutionV, Twist	H1, ResolutionH, ResolutionV, *a	H1, ResolutionH, ResolutionV, Twist *a	H1, D, alpha, ResolutionH, ResolutionV, Twist	Type= <dodecaeder,ikosadeder, triangles:value> value=<number of triangles> ,*b	height=value (height of middle point of the sphere), radius=<value> (radius of the sphere) cutting:sphere:top=<value> Hc - Horizontal cutting plane of the sphere on the top or: cutting:sphere:down=<value> Hc - Horizontal cutting plane of the sphere down
Description	Sehe: [3] Any floor plan possible	If H1=H2 and L1=L2 then A horizontal parabolic cylinder (see pict right) Any floor plan possible	Often used in industry	The same mathematical definition like 8.3 but not cutted in the middle			tent surface	Geodesic dome, examples:[4],[5]	just a sphere
Restrictions									no negative values
Implemented	no	no	no	no	no	no	no	no	no

(*a) clarify: are this parameters enough?

(*b) nr of triangles=20*n*n or 60*n*n. For understanding of details see page of Werner Brefeld: [6]

• Twist -rotation along z axis. Example see: [7]
• ResolutionH : number of segments of floor plan (when change to regular polygon with n sides wished)
• ResolutionV : number of segments of building height

Subtype 9

Subtype 9 describes the so called generic shapes.

The assumption is that all roof faces of the building start at the same height and have the same inclination. These roof areas can be generated on any floor plan.

This method is particularly convenient because very few tags can describe common roof geometry for large, complex roofs.

Top view
Type	9.0	9.1	9.2
OSM tagging value	equal_hipped	equal_mansard	flat_mansard
Parameters	alpha H is the maximal height resulting from alpha	H1, alpha , H1 is the height of the lower roof side.	H1, alpha 1
Restrictions	none
Implemented	yes	in progress	in progress

Tagging Proposal

Attribut	Value	Description
building	yes, *	just building..
3dr:type	e.g. 2.0	Describes roof type. E. g. 2.0. Tagging for the quick manual input can be supplemented with the description of the dormers. Extended version can looks like 3dr:type=2.0.a.a)
Parameters for roof type :
3dr:height1	[m, d] default meter	The parameter describing the first height for a given type of roof.
3dr:height2	[m, d]	The parameter describing the second height for a given type of roof.
3dr:heightX
3dr:length1	[m, %] Domyślnie %.	The parameter describing the first length for a given type of roof.
3dr:length2	[m, %] Domyślnie %.	The parameter describing the second length for a given type of roof.
3dr:lengthX	[m, %]	The parameter describing the the next (X) lengths
Dormers
3dr:dormer	E.g. "aa.a"	Atrybut opisujący kolejne lukarny uporządkowane w grupy. Grupy lukarn rozdzielone są kropkami. Grupa mogą zostać przypisane do krawędzi obrysu budynku lub do boku prostokąta opisującego dany obrys. W przypadku przypisania do krawędzi numer grupy odpowiada numerowi krawędzi obrysu. Sposób przypisania określa atrybut 3dr:donor:type. Domyślnie grupy przypisane są do krawędzi. Brak atrybutu oznacza przypisanie grup do krawędzi =rect Lukarny podane w tym atrybucie są nadrzędne względem tych podanych w atrybucie building:roof:3dr:type. Wartość dotycząca lukarn z atrybutu 3dr:type powinna zostać automatycznie przenoszona do tego pola po zakończeniu edycji.
3dr:donor:type	"rect"	Określa sposób przypisania grup lukarn. Wartości: Domyślne brak, rect - przypisanie grup do krawędzi prostokąta opisującego obrys budynku.
3dr:dormer:width	[m]	Wartość domyślna dla wszystkich nadbudówek dla danego dachu. Opisuje szerokość nadbudówki [domyślnie m]
3dr:dormer:heightX	[m, d]	Wartość domyślna dla wszystkich nadbudówek dla danego dachu. Wysokość nadbudówki [domyślnie m, dla niektórych dozwolone stopnie]
3dr:dormer:lengthX	[m, %]	Parametr opisujący kolejne długości nadbudówki

The position of the tagged point corresponds to the symmetry axis of the dormer.

Examples

Roof based on shape of rectangle

Some roof base on shape of rectangle and only for this shape can exist. Building polygon not always have only four nodes. And it can have different shape than rectangle. Example of this building polygon is:

Example of roofs based on rectangle are types: 0.*, 1.*, 2.*, 3.*, 4.*, 5.* ?, 7.*

Examples

Type 2.1	Type 5.2	Type 5.6
		3D view:

In case of type 5.6 we find the biggest circle inside building polygon. The circle is base for roof sphere (red surface on image, shared points are marked blue) rest of roof is generated flat (gray color).

Generation of building bounding box.

To generate 3D model for building polygon which is not rectangle at first place we need to find the smallest rectangle containing building polygon. It is easy to generate shape of building roof for rectangle and it is easy to place dormers using this rectangle.

Example of generating roof for complex building polygon:

Roof properties

Because roofs are base on rectangle, rectangle sizes are taken in to account in process of roof generation. Each roof type has properties describing it's shape eg. 3dr:length. If properties are write in presents true size of properties are calculated using presents and rectangle sizes.

Some times automatically generated bounding rectangle (red color) is not as we expected (green color):

Starting point

When we need to describe roof with precision it is necessary to determinate roof direction. Now day proposals using tag building:roof:orientation= along|across. Unfortunately this tag is not enough because:

1. There are building polygons which are square. In that case value of tag is pointless and there are four way to generate roof model

2. There are roof shapes which have four like type 1.0 or more ways to generate roof model:

next tags leike along, rotated or mirrored make the tagging system prone to errors.

3. Dormers needs to precisely mark where roof “begins”

To precisely mark where roof “begins” we need to choose some point as start point. There is not need to add additional tags for node because building polygon has defined nodes direction. We can use start point as point first point on building polygon.

Warning. Starting point for building polygon is not visible in osm editors!

Polygon direction

By default bounding rectangle is generated as the smallest rectangle write on building polygon. Not always we expected this behavior. To change this we need add additional tags describing direction of bounding rectangle. Direction of rectangle affects on location of dormers because it describing where it is front of building.

Example:

Method 1

Using tags assigned to nodes of building polygon. Two of nodes have assigned tag 3dr:direction=begin|end. Method may by used for single buildings which don't share walls.

Tag	Description
3dr:direction=begin	Begin of vector describing direction of roof.
3dr:direction=end	End of vector describing direction of roof.

Status Implemented

Method 2

Points describing direction are write using relation. This allow for buildings with shared walls.

Relation type: 3dr

Any node with role 3dr:direction:begin

Any node with role 3dr:direction:end

Warning It may change

Warning Not implemented

Places for dormers

For roofs base on rectangle there are four place where we can put dormers. Places are connected with edges of rectangle containing building polygon. Example image:

Places number on roof	Tag	Tag (Alternative) (not working)	Description
place 1	3dr:dormers:front	3dr:dormers:1	Front
place 2	3dr:dormers:right	3dr:dormers:2	Right side
place 3	3dr:dormers:back	3dr:dormers:3	Back
place 4	3dr:dormers:left	3dr:dormers:4	Left side

Not for all roofs shapes all four places are available. In example above for roof shape type 2.0 there are only two places for dormers. There are places 1 and 3 (front and back). All others places are ignored.

Warning Currently not implemented. Currently dormers can be setup using tag 3dr:type=2.0.aa.b

Complex roof geometry

The complicated roofs should be described as a sum of single simple components

Name translation

The both descriptions for the roof geometry are compatible. You can write "0.0" or "flat".We are working on understandable description for every roof types.

Names for roof types:[8] :

"roof table"	"building attributes"
0.0	flat
1.0	skillion
2.0	gabled
2.3	half-hipped
2.4	hipped
2.5	pyramidal
3.0	half_saltbox*
3.1	saltbox*
3.2	corner_saltbox
3.3	triple_saltbox
3.4	quadruple_saltbox
4.0	gambrel
4.1 , 4.2	mansard
4.3	helm
5.0	round
5.2	half_round
5.6	dome
6.0	three_aisled
6.2	crosspitched
6.3	five_aisled
7.1.n	sawtooth
7.2.n	trapeze
7.3.n	gabled_row
7.4.n	round_row
7.5.n	wave
8.0	cone
8.1	hyperbolic_paraboloid
8.2	parabolic
8.3	hyperbolic_tower
8.4	elliptic_hyperboloid
8.5	ellipsoid_cutted
8.6	elliptic_paraboloid
8.7	tent
8.8	geodesic_dome
8.9	spherical_cutted
9.0	equal_hipped

• Note: the common german name for the both roof subtypes is "Berliner Dach". See: [9]

Comparison table with: Image - roof_table - building attributes at: Dachformen.pdf --Geri-oc 18:41, 7 December 2011 (UTC)