A basic BIM as a Django 2.0.2 / Wagtail 2.0 app that imports CAD files and renders Virtual Reality using A-Frame 0.8.2 library.
Main project was named BIMba, which stands for "basic Building Information Modeling". Later the app was written in Python, so BI became PY. This special version is integrated in Bakery, a Wagtail demo.
DXF files are drawing exchange files, and they are human readable (if in ASCII format). Obviously you will need a CAD if you want to generate your own files. For free I recommend NanoCAD even if you won't be able to work with solids. It doesn't matter, you won't need them. Unfortunately open source CAD projects never match the industry.
Lots of programs deal with DXF, but the goal here is to have blocks with attributes (data!), not just surfaces. Refer to the DXF constraints paragraph to understand what your files have to look like.
The app can be cloned or downloaded from Github. Using a shell get into the project folder and type git clone https://github.com/andywar65/pymbake. Add pymbake to the INSTALLED_APPS in your settings file. Migrate and Collectstatic. The app's templates look for a base.html file, so be sure to have one.
Generate a DXF in ascii mode and don't try to modify it. DXF is a sequence of key / value pairs, and deleting just one line can break up everything. By now only 3Dfaces and standard blocks (see further) can be translated, other entities will just be ignored. Create as many layers as you need, and place your entities on the desired one. Layers relate to the appearance of the entity, how it's explained in the backend paragraph.
To include meshes, explode them to 3Dfaces (I know it's bad, but this is how it works by now). If you have an Acis solid, use 3DCONVERT to obtain a mesh, then explode it.
Create a page of the Pymbake Page kind. You will have to enter a Title and an Intro and an Image for the page. In the VR Settings panel load the most important stuff: the DXF file. It will be stored in the media/documents folder. Then load the Equirectangular Image for the VR background (if none, a default one will be picked). Equirectangular images are like those planispheres where Greenland is bigger than Africa. Then you will have to check if you want your shadows on, if you want your camera to be able to fly and if 3D faces must be double sided.
At first entities inherit the original layer color, but you can change that creating as many Material Gallery items as the layers used in the DXF file. Each material needs a Name that must match the layer name (default is 0), an Image that will be applied to the entity and a Color. If the image is a 1x1 meter pattern, check the appropriate box. Default color is white, but you can use hexadecimal notation (like #ffffff) or standard HTML colors. Color affects appearance of the image. You can set the Material to Invisible, and it's like turning the layer off.
Okay, now publish and go to the frontend to see how your model behaves.
The model window is embedded within your website, but you can go fullscreen by pressing F or the visor icon in the right bottom corner of the window. On some mobiles the image will be split in two, with stereoscopic effect. You will need one of those cardboard headgears to appreciate the effect. Press ESC to exit fullscreen mode. On laptops, if you want to look around, you have to press and drag the mouse. To move around press the W-A-S-D keys. On some mobiles you literally walk to explore the model, but I've never experienced that. Some elements like Doors have animations, just click on them.
Last but not least, press the Ctrl+Alt+I to enter the Inspector mode, that makes you inspect and modify the entities of the model. Modifications can be saved to HTML files.
When you have several Pymbake Pages you can collect them under a Pymbake Index Page. This page acts like a blog index. Style is borrowed by the Bakery CSS.
Standard blocks may be found in static/pymbake/samples/standard-blocks.dxf bundled within the app: box, cylinder, cone, sphere, circle, plane, look-at, text, links, curvedimage and lights. These mimic entities of the A-Frame library, with unit dimensions. Insert the block and scale it to the desired width, length and height. You can rotate it along all axis (previous limitations solved thanks to Marilena Vendittelli). You can explode some of the standard blocks without affecting geometry: they will degrade to a series of 3D faces.
Standard blocks come with attributes that affect their geometry. In CAD, attributes are prompted when inserting a block, and can be modified in the Property window. To understand how attributes affect geometry, refer to A-Frame Documentation .
Light standard block has a type attribute which can be set to ambient, directional, point and spot. Directional light is best suited for shadowing. Scale light block to modify shadow camera frustum. Refer to A-Frame Light Component Documentation for further details.
Look-at standard block is a plane that always faces the camera.
Text standard block is a text centered in a bounding plane. The attributes control alignment, content and wrap count, which is the number of letters that fill the width of the bounding plane.
Link standard block allows you to link different pages on a click. The Tree attribute lets you select among parent, previous, next and first child page. If target has an equirectangular image (see backend paragraph) it will appear in the link.
Curvedimage standard block is an open cylinder where you can project panoramic images.
Animation standard block animates the blocks that have same insertion point in CAD file. Refer to A-Frame Animation Component Documentation for further details on animation attributes.
BIM standard blocks are recognized as real life building elements. By now we have Wall, Slab, Door and Furniture BIM entities. If you put a Door inside a Wall, you get a Openwall. Partition blocks behave pretty much as a box, but attributes are different: we can set a Type for each wall/slab and a Finishing for each side.
Wall and Slab types are defined in the backend as Pymbake Pertition Pages, and must be children of the Pymbake Page they are related to. Creating a new partition type requires Title, Intro, Image (is it a pattern?) and Color. You can then add as many wall Layers to the Partition Type as you want. Layers require a Material, a Thickness (in centimeters) and a Weight in kilograms per cubic meter.
First layer is innermost for Walls and uppermost for Slabs. The app controls if wall/slab dimensions in CAD are consistent with Partition Type features, i.e. wall/slab thickness. If inconsistency arises, wall/slab is rendered in flat red. You can leave a layer with zero thickness to assign the same Partition Type to entities with different depth. If you view a Partition Page, a schematic partition will be displayed, featuring layer names and thickness.
Finishings are defined in the backend as Pymbake Finishing Pages, and must be children of the Pymbake Page they are related to. Creating a new finishing requires Title, Intro, Image (is it a pattern?) and Color for General, Tiling and Skirting appearance. Tiling and Skirting require also height, intended as their upper bound with respect to the floor. Slabs use skirting image and color for floor appearance. If you view a Finishing Page, a collection of BIM entities will be displayed, featuring finishing patterns.
Doors can be hinged or sliding, single or double. Geometry and behaviour are defined in CAD (block dimension and attributes), appearance is defined by finishing (tiling for the panel and skirting for the frame). If you set type attribute to ghost, door panel is not rendered. If a door panel is clicked, an animation is triggered.
Furniture blocks have type and finishing attributes. There will be a list of furniture types (by now only t01 = simple table). The finishing attribute relates to a Finishing Page with equal title as the attribute. Geometry is defined in CAD.
BIM entity data is stored in a CSV file downloadable from the frontend. Data includes wall/slab weight and finishing surfaces.
Make other furniture.