Manual:BIM modeling/es

El modelado de información de construcción significa (BIM, engl.: Building Information Modelling) . La definición exacta de lo que es varía, pero podemos decir simplemente que es la forma en que se modelan hoy en día los edificios y otras grandes estructuras como puentes, túneles, etc. Los modelos BIM suelen basarse en modelos 3D, y además incluyen una serie de capas de información adicionales, como información sobre materiales, relaciones con otros objetos o modelos, o instrucciones especiales para la construcción o el mantenimiento. Esta información adicional permite todo tipo de análisis avanzados del modelo, como la resistencia estructural, la estimación de costes y tiempos de construcción o el cálculo del consumo energético.

El Ambiente de trabajo Arquitectura de FreeCAD implementa una serie de herramientas y facilidades para el modelado BIM. Aunque tiene un propósito diferente, está hecho para trabajar en estrecha integración con el resto de FreeCAD: Cualquier cosa hecha con cualquier otro banco de trabajo de FreeCAD puede convertirse en un objeto Arch, o ser utilizado como base para un objeto Arch.

Como en el Ambiente de trabajo Disegno Piezas, los objetos producidos por el Arch Workbench están destinados a ser construidos en el mundo real. Por lo tanto, necesitan ser sólidos'. Las herramientas de Arch normalmente se encargan de ello automáticamente, y también proporcionan herramientas de utilidad para ayudarte a comprobar la validez de los objetos.

El ambiente de trabajo Arquitectura también incluye todas las herramientas del Ambiente de trabajo de Borrador, y utiliza su sistema de rejilla y ajuste. Antes de empezar, siempre es una buena idea navegar a través de las páginas de preferencias tanto de Draft como de Arch y establecer la configuración por defecto a su gusto.

En este capítulo veremos cómo modelar este pequeño edificio:



y producir una vista en planta y en sección a partir de ella:



NOTA: Debido a un error en la versión 0.18, asegúrese de hacer las líneas en este orden y esta dirección.
 * Crear un nuevo documento, y cambiar al Ambiente de trabajo Arquitectura.
 * Abra el menú y establezca:
 * Líneas principales cada.
 * Espaciado de la cuadrícula para tener una cuadrícula basada en un metro, lo cual es conveniente para el tamaño de nuestro edificio.
 * Tamaño de la cuadrícula.
 * En la barra de herramientas de snapping asegúrese de que el [[Image:Draft_Snap_Grid.svg|16px]] grid snap esté habilitado, para que podamos usar la rejilla tanto como sea posible.
 * Si no ves los ejes entonces haz clic en el [[Image:Draft_Snap_Grid.svg|16px]] alternar rejilla de borrador.
 * Establece el Plano trabajo en el plano XY
 * Aleja el zoom y desplázalo para que puedas ver el área desde (0,0) hasta (4,3). Ver el Mouse Model para las instrucciones.
 * Dibuja cuatro líneas con la herramienta [[Image:Draft_Line.svg|16px]] Borrador línea. Puedes introducir las coordenadas manualmente, o simplemente elegir los puntos de la cuadrícula con el ratón:
 * Del punto (0,0) al punto (0,3)
 * Del punto (0,3) al punto (4,3)
 * Del punto (4,3) al punto (4,0)
 * Del punto (4,0) al punto (0,0)



Observa que hemos dibujado siempre en la misma dirección (en el sentido de las agujas del reloj). Esto no es necesario, pero asegurará que las paredes que construiremos a continuación tengan todas la misma dirección izquierda y derecha. También podrías pensar que aquí podríamos haber dibujado simplemente un rectángulo, lo cual es cierto. Pero las cuatro líneas nos permitirán ilustrar mejor cómo añadir un objeto dentro de otro.


 * Once your have created the lines check their start and end points and adjust if necessary to get them exactly correct.


 * Select the first line, then press the [[Image:Arch_Wall.svg|16px]] Wall button.
 * Repeat this for the 3 other lines, until you have 4 walls.
 * Select the four walls, and set their Height property to 3.00m and their Alignment property to left. If you didn't draw the lines in the same order as we did above, some of the walls might have their left and right directions flipped, and might need to be set to right instead. You will obtain four intersecting walls, on the inside of the baselines:



Now we need to join these walls together, so they intersect properly. This is not necessary when your walls are drawn in a way that they already connect cleanly, but here we need to, since they are intersecting. In Arch, this is done by electing one of the walls to be the "host", and adding the others to it, as "additions". All arch objects can have any number of additions (objects whose geometry will be added to the host's geometry), and subtractions (objects whose geometry will be subtracted). The additions and subtractions of an object can be managed anytime by double-clicking the object in the tree.
 * Select the four walls with pressed, the last one being the wall that you chose to become the host
 * Press the [[Image:Arch_Add.svg|16px]] Add button. The four walls have now been turned into one:



The individual walls are however still accessible, by expanding the wall in the tree view.


 * Let's now place a door. In FreeCAD, doors are considered a special case of windows, so this is done using the Window tool.
 * Start by selecting the wall. This is not necessary, but a good habit to take. If an object is selected when starting the window tool, you will force the window to be inserted in that object, even if you snap to another object.
 * Set the Working Plane to auto so we are not restricted to the ground plane
 * Press the [[Image:Arch_Window.svg|16px]] Window button.
 * In the window creation panel, select the Glass door preset, and set its Width to 0.9m and its Height to 2.1m
 * Make sure the [[Image:Draft_Snap_Near.svg|16px]] Near snap location is turned on, so we can snap on faces
 * Place your window roughly on the middle of the front face of the wall:




 * After clicking, our window is placed on the correct face, but not exactly where we want:




 * We can now set the precise location by expanding the wall and the window objects in the tree view, and changing the Placement property of the base sketch of our door. Set its position to x = 2m, y = 0, z = 0. Our window is now exactly where we want it:




 * Repeat the operation to place a window: Select the wall, press the window tool, select the Open 2-pane preset, and place a 1m x 1m window in the same face as the door. Set the placement of the underlying sketch to position x = 0.6m, y = 0, z = 1.1m, so the upper line of the window is aligned to the top of the door.



Windows are always built on sketches. It is easy to create custom windows by first creating a sketch on a face, then turning it into a window by selecting it, then pressing the window button. Then, the window creation parameters, that is, which wires of the sketch must be extruded and how much, can be defined by double-clicking the window in the tree view. Now, let's create a slab:


 * Set the Working Plane to XY plane
 * Create a [[Image:Draft_Rectangle.svg|16px]] rectangle with a length of 5m, a height of 4m, and place it at position x:-0.5m, y:-0.5m, z:0.
 * Select the rectangle
 * Click the [[Image:Arch_Structure.svg|16px]] structure tool to create a slab from the rectangle
 * Set the height property of the slab to 0.2m and its normal direction to (0,0,-1) because we want it to extrude downwards. We could also simply have moved it 0.2m down, but it is always good practice to keep extruded objects at the same place as their base profile.
 * Set the Ifc Type property of the slab to slab. This is not necessary in FreeCAD, but is important for IFC export, as it will ensure that the object is exported with the correct IFC type.




 * Let's now use one of the structural presets to make a metallic beam. Click the [[Image:Arch_Structure.svg|16px]] structure button, select a HEB 180 preset, and set its height to 4m. Place it anywhere:




 * Adjust its placement by setting its Angle to 90° in the (1,0,0) axis, and its position to x:90mm, y:3.5m, z:3.09m. This will position the beam exactly on one of the side walls:




 * We need now to duplicate this beam a couple of times. We could do that one by one using the [[Image:Draft_Clone.svg|16px]] clone tool, but there is a better way, to do all the copies at once using an array:
 * Select the beam
 * Press the [[Image:Draft_OrthoArray.svg|16px]] Draft OrthoArray button
 * Set the Number of elements for the X direction of the array to 6, set the number for the Y and Z direction to 1, and press OK.
 * Expand the interval X property of the array, and press the small [[Image:Bound-expression-unset.png|16px]] expression icon at the right side of the X field. This will open an expressions editor:




 * Write (4m-180mm)/5 in the expression field, and press OK. This will set the x value to 0.764 (4m is the total length of our front wall, 180mm is the width of the beam, which is why it is called HEB180, and we want a fifth of that space as interval between each beam):




 * We can now easily build a simple slab on top of them, by drawing a rectangle directly on the top plane of the beams. Select a top face of one of the beams
 * Press the [[Image:Draft_SelectPlane.svg|16px]] working plane button. The working plane is now set to that face.
 * Create a [[Image:Draft_Rectangle.svg|16px]] rectangle, snapping to two opposite points of the border beams:




 * Select the rectangle
 * Click the [[Image:Arch_Structure.svg|16px]] structure button and create a slab with a height of 0.2m.

That's it, our model is now complete. We should now organize it so it exports correctly to IFC. The IFC format requires that all objects of a building are inside a building object, and optionally, inside a story. It also requires that all buildings are placed on a site, but the IFC exporter of FreeCAD will add a default site automatically if needed, so we don't need to add one here.


 * Select the two slabs, the wall, and the array of beams
 * Press the [[Image:Arch_Floor.svg|16px]] Floor button
 * Select the floor we just created
 * Press the [[Image:Arch_Building.svg|16px]] Building button

Our model is now ready to export:



The IFC format is one of the most precious assets in a free BIM world, because it allows the exchange of data between any application and actor of the construction world, in an open manner (the format is open, free and maintained by an independent consortium). Exporting your BIM models as IFC ensures that anyone can see and analyze them, no matter the application used.

In FreeCAD, IFC import and export is done by interfacing with another piece of software, called IfcOpenShell. To be able to export to IFC from FreeCAD, the IfcOpenShell-python package must be installed on your system. Be sure to select one which uses the same python version as FreeCAD. The python version that FreeCAD uses is informed when opening the View -> Panels -> Python console panel in FreeCAD. When that is done, we can now export our model:


 * Select the top object you want to export, that is, the Building object.
 * Select menu File -> Export -> Industry Foundation Classes and save your file.
 * The resulting IFC file can now be opened in a wide range of applications and viewers (the image below shows the file opened in the free IfcPlusPlus viewer). Checking the exported file in such a viewer application before distributing it to other people is important to check that all the data contained in the file is correct. FreeCAD itself can also be used to re-open the resulting IFC file.



We will now place some dimensions. Unlike the previous chapter, where we drew all the dimensions directly on the Drawing sheet, we will use another method here, and place Draft dimensions directly in the 3D model. These dimensions will then be placed on the Drawing sheet automatically. We will first make two groups for our dimensions, one for the dimensions that will appear in the plan view, and another for those that appear on the elevation.


 * Right-click the "house" document in the tree view, and create two new groups: Plan dimensions and Elevation dimensions.
 * Set the Working Plane to XY plane
 * Make sure the [[Image:Draft_Snap_WorkingPlane.svg|16px]] restrict snap location is turned on, so everything you draw stays on the working plane.
 * Draw a couple of [[Image:Draft_Snap_Dimensions.svg|16px]] Dimensions, for example as on the image below. Pressing and  while snapping the dimension points will give you additional options.




 * Select all your dimensions, and drag them to the Plan dimensions group in the tree view
 * Set the Working Plane to XZ plane, that is, the frontal vertical plane.
 * Repeat the operation, draw a couple of dimensions, and place them in the Elevation dimensions group.



We will now prepare a set of views from our model, to be placed on a Drawing page. We can do that with the tools from the Drawing Workbench, as we have seen in the previous chapter, but the Arch Workbench also offers an all-in-one advanced tool to produce plan, section and elevation views, called Section Plane. We will now add two of these section planes, to create a plan view and an elevation view.
 * Select the building object in the tree view
 * Press the [[Image:Arch_SectionPlane.svg|16px]] Section Plane button.
 * Set its Display Height property to 5m, its Display Length to 6m, so we encompass our house (this is not needed, but will look better, as it will show naturally what it is used for), and its Placement position at x:2m, y:1.5m, z:1.5m.
 * Check the list of objects considered by the Section Plane by double-clicking it in the tree view. Section Planes only render specified objects from the model, not all of them. The objects considered by the Section Plane can be changed here.




 * Repeat the operation to create another section plane, give it the same display length and height, and give it the following Placement: position: x:2m, y:-2m, z:1.5m, angle: 90°, axis: x:1, y:0, z:0. Make sure this new section plane also considers the building object.




 * Now we have everything we need, and we can create our Drawing page. Start by switching to the Drawing Workbench, and create a new default [[Image:Drawing_Landscape_A3.png|16px]] A3 page (or select another template if you wish).
 * Select the first section plane, used for the plan view
 * Press the [[Image:Drawing_DraftView.png|16px]] Draft View button. This tool offers a couple of additional features over the standard Drawing View tool, and supports the Section Planes from the Arch Workbench.
 * Give the new view the following properties:
 * X: 50
 * Y: 140
 * Scale: 0.03
 * Line width: 0.15
 * Show Cut True
 * Show Fill: True
 * Select the other section plane, and create a new Draft View, with the following properties:
 * X: 250
 * Y: 150
 * Scale: 0.03
 * Rendering: Solid



We will now create two more Draft Views, one for each group of dimensions.


 * Select the Plan dimensions group
 * Press the [[Image:Drawing_DraftView.png|16px]] Draft View button.
 * Give the new view the following properties:
 * X: 50
 * Y: 140
 * Scale: 0.03
 * Line width: 0.15
 * Font size: 10mm
 * Repeat the operation for the other group, with the following settings:
 * X: 250
 * Y: 150
 * Scale: 0.03
 * Line width: 0.15
 * Font size: 10mm
 * Direction: 0,-1,0
 * Rotation: 90°

Our page is now ready, and we can export it to SVG or DXF formats, or print it. The SVG format allows you to open the file using illustration applications such as Inkscape, with which you can quickly enhance technical drawings and turn them into much nicer presentation drawings. It offers many more possibilities than the DXF format.

Descargas

 * The file produced during this exercise: https://github.com/yorikvanhavre/FreeCAD-manual/blob/master/files/house.FCStd
 * The IFC file exported from the above file: https://github.com/yorikvanhavre/FreeCAD-manual/blob/master/files/house.ifc
 * The SVG file exported from the above file: https://github.com/yorikvanhavre/FreeCAD-manual/blob/master/files/house.svg

Relacionados

 * Ambiente de trabajo BIM
 * Ambiente de trabajo Arquitectura
 * El Borrador plano de trabajo
 * Los ajustes Borrador Atrapar
 * El sistema de expresiones
 * El formato IFC
 * IfcOpenShell
 * IfcPlusPlus
 * Inkscape