Roof table

Roof table
Status:	Draft (under way)
Proposed by:	Marek Strassenburg Kleciak, Kendzi
Tagging:	type=
Applies to:
Definition:	description of allowed roof geometry and building parts for parametric 3D modelling of buildings.
Rendered as:	JOSM PlugIn Kendzi3D
Draft start:	2011-06-09
RFC start:
Vote start:
Vote end:

This page is the working version and currently not updated!. For latest details see polish or german version. The english translation comes soon!

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

Contents 1 Flat roofs 2 Roofs with one sloping face 3 Roofs with 2 faces 4 Roofs with more sloped faces 4.1 Subtype 3 4.2 Subtype 4 4.3 Subtype 5 4.4 Subtype 6 4.5 Subtype 7 4.5.1 Inversion and half end 4.6 Subtype 8 4.6.1 8.A 4.6.2 8.B 4.7 Subtype 9 5 Tagging Proposal 6 Examples 6.1 Roof based on shape of rectangle 6.1.1 Examples 6.1.2 Generation of building bounding box. 6.1.3 Roof properties 6.2 Starting point 6.3 Polygon direction 6.4 Places for dormers 7 Complex roof geometry 8 Name translation

Flat roofs

3D View / Top view + Sideviews
Typ	0.0	0.1	0.2	0.3	0.4
Parameters		H1, L1	H1, L1, L2 *.a	H1, L1, L2, L3 *.a	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

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

Roofs with one sloping face

3D View / Top view + Sideviews
Typ	1.0	1.1
Parameters	H1	H1, H2, H3 *a
Restrictions	none	none
Implemented	yes	yes

(*a) = if only H1,H2 then H3 = H2 (Info: H4 is not necessarily then H4=2 x H2)

Roofs with 2 faces

3D View / Top view + Sideviews
Typ	2.0	2.1	2.2	2.3	2.4
Parameters	H1, L1 *a	H1, H2, L1 *a	H1, L1, L2 *a, *b	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

3D View / Top view + Sideviews			(image has mix l1 and l2)
Typ	2.5	2.6	2.7	2.8	2.8 (subform)
Parameters	H1, L1, L2 *a	H1, L1 *b	H1, L1, L2 *c	H1, H2, H3 *d	H1, H2, H3 *e
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 more sloped faces

Subtype 3

3D View / Top view + Sideviews
Type	3.0	3.1	3.2	3.3	3.4
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
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 Symmetry, then only L1, L2 necessary

Typ 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
Parameters	H1	H1	H1	H1, L1	H1, L1, L2	H1, L1, L2	H1
Restrictions				L1<width	L1+L2<width	L1+L2<width	H1≤0,5*depth
Implemented

Subtype 6

3D View / Top view + Sideviews
Typ	6.0	6.1	6.2	6.3	6.4
Paramaters	H1, H2, H3, L1	H1, H2, H3, H4, H5, H6, H7	H1	H1, H2, H3, H4, H5	H1, n
Description	Dreischiffige 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	7.2.n	7.3.n	7.4.n	7.5.n
Parameters	H1	H1	H1	H1	H1	H1
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
Parameters	H1	H1,H2,L2	H1,H2,H3,L2,L3	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 [1]	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		..						soon
Type	8.1	8.2	8.3	8.4	8.5	8.6	8.7	8.8
Parameters	H1,H2,H3	H1,H2,L1,L2,ResolutionH, ResolutionV	H1,D1, Twist, ResolutionH, ResolutionV	H1,D1,D2,ResolutionH, ResolutionV, Twist	H1,D1, ResolutionH, ResolutionV,Twist *a	H1, ResolutionH, ResolutionV, Twist *a	H1, D, alpha, ResolutionH, ResolutionV, Twist	Type:<dodecaeder,ikosadeder>,triangles:<number of triangles> *b
Description	Sehe: [2] 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:[3],[4]
Restrictions
Implemented	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: [5]

• Twist -rotation along z axis. Example see: [6]
• 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 die sog. generic shapes. Assumption: All roof faces of the building with the beginning in the same height, have the same inclination. There are generated roof surfaces on any possible outline geometry.

Top view
Type	9.0	9.1	9.2
Restrictions	none
implemanted	yes	in work	in work

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:lenght1	[m, %] Domyślnie %.	The parameter describing the first lenght for a given type of roof.
3dr:lenght2	[m, %] Domyślnie %.	The parameter describing the first lenght for a given type of roof.
3dr:lenghtX	[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:lenghtX	[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:lenght. 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:[7] :

"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	saltbox
3.1	double_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

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