基于BIM技术的室内照明仿真模拟软件计算精度解析

建筑照明专业参与BIM （building information modeling）技术的同平台作业还处于起步阶段。DIALux evo 8.2和ElumTools 2019.07是目前仅有的参与BIM技术的室内照明仿真模拟软件。采用CIE （Commission Internationale de i''Eclairage）发布的CIE 171：2006—test cases to assess the accuracy of lighting computer programs的5.2至5.8测试用例,通过验证这2款软件的计算精度,分析得出软件性能的优缺点。结果表明：在计算点光源直接照度、面光源直接照度以及光通量守恒性能这3个方面,2款软件均具有较高精度;计算大面积漫反射、遇遮挡和不同反射率这3种情况的间接照度时,DIALux evo 8.2计算精度优于ElumTools 2019.07;计算小面积漫反射的间接照度精度时,ElumTools 2019.07计算精度优于DIALux evo 8.2;计算定向透射性能时,这2款软件精度均比较低。进一步分析得出：核心算法是产生误差的主要原因,2款软件信息交换均存在一定缺陷。因此,采用光子映射算法,创建建筑与照明全信息交换接口将成为未来基于BIM技术的室内照明仿真模拟软件的研发方向。

Computation accuracy analysis of indoor lighting simulation software based on BIM technology

The integration of lighting profession and building information modelling (BIM) technology on the same platform is still in its infancy. DIALux evo 8.2 and ElumTools 2019.07 are currently the only indoor lighting simulation software that participate in BIM technology. The calculation accuracy of them were verified using the cases 5.2 to 5.8 in CIE171:2006-test cases to assess the accuracy of lighting computer programs which published by CIE (Commission Internationale de i''Eclairage). Then the advantages and disadvantages of them were analysed. The results show that 1) both of them have high accuracy in calculating the direct illuminance of point light source and area light source, and luminous flux conservation performance; 2) the accuracy of DIALux evo 8.2 is better than ElumTools 2019.07 when calculating the indirect illuminance of large-area diffuse reflection, occlusion and different reflectivity; 3) ElumTools 2019.07 has higher accuracy when calculating small-area diffuse reflection; 4) both of them have relatively low accuracy when calculating directional transmission performance. Based on the case study, it is further concluded that the core algorithm is the main cause of errors, and both of them have defects in information exchanges. The use of photon mapping algorithms to create a full information exchange interface between buildings and lighting will be the future direction of indoor lighting simulation software development based on BIM technology.