1 Introduction to BIM Technology
BIM is the abbreviation of BuildingInformationModeling. It is a technology, method or process that uses digital technology to express the geometric, physical and functional information of construction projects to support construction, operation and management decisions in the project life cycle. The project information model established with BIM technology is called the BIM model. It contains all the geometric and non-geometric information of the building (such as the physical properties of the material, the price of the component, etc.). Specifically, the advantages of BIM technology are mainly reflected in the following four aspects:
(1) Visualization
In the current architectural design environment, the relevant drawings of the building are only the individual components on the drawings to draw expressions, although the renderings made by the modeling software can make people have a sensory understanding of the appearance of the building, but it involves the structural form and System pipelines and the like cannot be directly presented in three dimensions, and it is necessary for a professional to imagine using a plan paper. In this way, errors that do not correspond to drawings often occur, and the relationship between the units inside the building cannot be well observed. BIM provides a visual idea. With BIM software, designers can create a virtual building model of what they see is what they want. It includes not only the three-dimensional appearance model of the building, but also the three-dimensional model of the equipment system such as plumbing. At any stage of the design, you can see the design of each part at any time.
(2) Simulation analysis
Drawings drawn in 2D CAD can never be intelligently analyzed and simulated. It is often necessary to model the calculations separately in the relevant analysis software, which will take a lot of time, and the rough model will cause errors in the calculation. The information model created by using BIM technology contains all the data information. Therefore, the model can be imported into the analysis and simulation software based on BIM technology, and then structural analysis, thermal performance analysis, pipeline conflict inspection, fire safety inspection, energy can be performed. Analysis, specification testing, etc. Not only saves time, but also ensures the accuracy of the data and optimizes the design.
(3) Multi-professional collaborative design
Since the building information model contains all the information parameters in the building, the various types of construction (architects, structural engineers, equipment engineers, etc.) can be collaboratively designed based on this model. For example, the equipment professional can upload the information model of the built equipment part to the core data model, and then use the relevant software to perform collision detection. After finding the design conflict, feedback to the relevant professional designers and make timely modifications.
(4) Drawing generation and associated modification
CAD-based design drawings, there is no information linkage between the graph and the graph. The error of one drawing often leads to the modification of a large number of drawings one by one, and the workload is large and cumbersome. BIM technology can avoid this phenomenon. The center of the design is the model rather than the drawing. At this time, the drawing is only the performance of the data in the same model from different angles, so the modification in any view will directly reflect in the model, so that Automatically updated in other views, which greatly reduces the workload of retouching and improving design efficiency.
2 The necessity of applying BIM technology to architectural lighting design
2.1 External promotion
BIM technology was originally designed for architectural design. After years of development, BIM's transformation of the construction industry has become an indisputable fact. It has innovative improvements in cost budgeting, site analysis, energy analysis, energy analysis, specification verification, and three-dimensional coordination of architectural design, and has become quite popular in the United States, Europe, and Japan. In recent years, the development speed of BIM in China is also amazing. The Ministry of Housing and Urban-Rural Development issued in 2011, “2011-2015 Construction Industry Informatization Development Outlineâ€, and basically realized the construction enterprises during the “Twelfth Five-Year Plan†period. Information systems and accelerated application of building information models. Reasonable policies and a good development environment offer the possibility of BIM application in architectural lighting design.
At the same time, more and more design institutes are shifting the design platform from 2D CAD to BIM, which shows that it has become the trend of future architectural design development. Today's BIM, its connotation has been greatly enriched compared with when it was first proposed. It is not only the architectural design profession, but also the sub-specialties of water supply and drainage, HVAC, electrical and other buildings benefit from BIM technology, and even the landscape architecture profession is also thinking. Can you introduce BIM technology into it? Under such a strong external force, architectural lighting is also used as a subsystem in the building system, and should also follow the trend to explore whether BIM technology can serve it.
2.2 Intrinsic requirements
In addition to the driving force, the industry's inherent needs are also an important reason for BIM to enter the architectural lighting industry. And to explore the inner needs should consider what BIM can solve in the lighting design. In general, the BIM technology in the existing design environment has the following aspects to improve the lighting design.
(1) Drawing modification
Similar to architectural design, lighting designers are also plagued by changes in drawings. BIM technology is based on an overall information model. As mentioned above, as long as the model is modified in any view, it will be automatically reflected in all the drawings, so that designers can spend more time and energy on the design. Instead of drawing and reshaping.
(2) Informatization
In the past, when designing various reports related to design, it is generally necessary to measure and count according to CAD files, and then use Excel and other software to produce reports. This kind of work is very cumbersome and error-prone. And once the drawings are modified, all data needs to be re-stated. Information is the core of BIM technology. Compared with the model established by traditional modeling software, the biggest feature of BIM model is carrying information. Therefore, the BIM model can also be understood as a repository that provides a real-time and reliable list of reports, such as fixture selection tables, switchboard schedules, and more. If the design is modified, the information in the report will be automatically modified, saving time and effort and ensuring the accuracy of the design.
(3) Integration
In lighting design, designers must strictly comply with relevant design specifications, such as illuminance levels, glare requirements, energy consumption indicators, and so on. Many lighting calculation software can calculate the relevant physical quantity more accurately, but in the current two-dimensional CAD design environment, the drawing can only be imported into the lighting software as a reference base map, and then re-modeled according to the base map and placed in the fixture. Calculation. Therefore, in order to save time, some designers often calculate by experience, so that the design can not be guaranteed. In addition to calculations, the lighting design finally provides the night scene renderings to the owners. At present, there are two main methods for domestic renderings: the first is to build a model with 3D modeling software such as 3DMAX, then put the light source file and generate it by rendering. The effect chart; the second method is to use the photoshop and other software to directly change the effect of the building day scene to the night scene effect. Regarding the first method, modeling is still a time-consuming task. Although the built model can be imported into the lighting calculation software, the placed light source is not recognized and needs to be relocated. For larger projects. Still taking time and effort. The second method requires the designer to have a good sense of light and imagination, in order to accurately select the color in the PS, and to achieve the exact color of the image and the actual use of the lamp is very small, so often the map and There is a gap in actual results. Since the BIM model contains information in the design, such as the light source, the optical properties of the surface material of the building, etc., it can not only illuminate the floor plan like the traditional CAD design, but also directly render it, or import the model into BIM-based technology. In the lighting calculation software, calculation is performed to realize the integration of lighting design drawing, calculation, rendering and other related steps.
(4) three-dimensional
In the current lighting design, the renderings can only reflect the lighting situation at a certain angle or in a certain area. For designers and owners, it is impossible to accurately understand all the conditions in the project area before the project is completed. BIM technology is a full three-dimensional technology, which can show people a three-dimensional virtual light environment. Designers can see the lighting situation in each area, in order to find problems and modify the plan in time, and substantially improve the lighting design. the quality of. In addition, through this full three-dimensional design pattern, the model of the lighting system can be directly seen, which facilitates the design and the subsequent construction.