## Appendix A Nonvisual Lighting Simulation Process  
For this process, a lighting simulation tool is required that allows (1) model construction (or model import); (2) setting reflection values to surfaces; (3) working with luminaire distribution files (such as LDT and IES files), including manipulating the luminous flux;(4) setting up measurement points and planes, especially in the gaze angle direction; and (5) simulation with physically correct or with acceptable abstraction (backward raytracing or radiosity method, respectively) for daylight and artificial light scenarios. Additional functions, such as table export and handling multiple scenes from the same model, are helpful but not required. Step 1: Model building. As far as geometry is concerned, the model is constructed as it would be for standard lighting design. When assigning materials, or, more specifically, reflection values \(\rho\) (rho), to the surfaces, two sets of values are used instead of one. Besides the photopic reflection values, melanopic reflection values \(\rho_{mel}\) are generated from spectral reflection measurements \(\rho_{\lambda}(\lambda)\) according to the following equation:  
\[\rho_{mel}=\int_{\text{380 nm}}^{\text{780 nm}}\rho_{\lambda}(\lambda)*s_{mel}( \lambda)\times d\lambda \tag{1}\]  
where \(s_{mel}(\lambda)\) denotes the melanopic spectral sensitivity curve [24]. If the spectral reflectance values of the materials cannot be obtained through measurements or databases, the latest version of the technical specification _DIN/TS 67600_ provides melanopic reflection values for some sample materials [57]. If transparent materials are used (such as glazing), transmittance values \(\tau\) (tau) are handled analogously. \"Measurement\" grids are added to the model as would be carried out in a standard simulation. Points or Grids at relevant eye levels are added. These can be oriented vertically, semi cylindrically, or in the exact gaze direction of the user. The orientation should depend on how well known and how variable a user's gaze is during their work processes. The simulation model is then split up into one file (or, scene, if available) using the photopic values and one using the melanopic values, called from here on the photopic model and melanopic model, respectively. Step 2: Light sources. Standard light distribution files are used, and light sources are placed inside all models. For the melanopic model, their luminous flux values are calculated from the following equation:  
\[\phi_{mel,v}^{\text{DGS}}=\phi_{v}\times a_{mel,v}\times 1.10375=\phi_{v} \times\frac{\int_{\text{380 nm}}^{\text{780 nm}}X_{\lambda}(\lambda)\times s_{mel}( \lambda)\times d\lambda}{\int_{\text{380 nm}}^{\text{780 nm}}X_{\lambda}(\lambda) \times V(\lambda)\times d\lambda}\times 1.10375 \tag{2}\]  
thereby deriving the _melanopic equivalent daylight (D65) luminous flux \(\phi_{mel,v}^{\text{D65}}\)_ (MEDLF, adapted from [24; 28]) from the luminous flux \(\phi_{v}\) and the melanopic action factor \(a_{mel,v}\). If \(a_{mel,v}\) is not known, the rightmost side of the equation calculates \(\phi_{mel}^{\text{D65}}\) from a basic measurement \(X_{\lambda}(\lambda)\), such as spectral radiance or irradiance, together with the spectral sensitivity curve \(s_{mel}(\lambda)\) and the photopic brightness sensitivity curve \(V(\lambda)\)[58]. If the spectral values of the light sources cannot be obtained through measurements or databases, the technical specification _DIN/TS 5031-100_ provides _melanopic action factors_ for standard types of light sources [28]. If the light source can be spectrally tuned, a separate MEDLF must be calculated for every configuration of interest, e.g., a 2700 K, a 4000 K, and a 6500 K setting. The luminous flux \(\phi_{v}\) has to also be adjusted if it varies with the spectral tuning. In the case of daylight, the luminous flux \(\phi_{v}\), and, therefore, the MEDLF, can generally not be set in simple simulation tools.