A method for generating planning data or control data for a radiation treatment, comprising the following steps: a) acquiring segmented data of an object which contains a treatment volume and a non-treatment volume (OAR1, OAR2); b) modelling at least some or all of the volume or surface of the treatment volume as a source of light or rays (ray1, ray2) exhibiting a predefined or constant initial intensity; c) modelling the non-treatment volume (OAR1, OAR2) as comprising volumetric elements or voxels which each exhibit an individually assigned feature or attenuation or transparency value (t min ≤ t ≤ t max) for the light or rays (ray1, ray2) which feature is assigned to the light or ray (ray1, ray2) or which attenuation or transparency maintains or reduces the intensity of the light or ray (ray1, ray2) as it passes through the respective volumetric element or voxel, wherein the feature or attenuation or transparency value is individually assigned to each volumetric element or voxel of the non-treatment volume (OAR1, OAR2); d) defining a map surface which surrounds and is outside of the treatment volume; e) calculating an accumulated intensity value for points or areas on the map surface, the accumulated intensity being the sum of the intensities of all the rays (ray1, ray2) which exhibit the predefined or constant initial intensity and are emitted from the volume or surface of the treatment volume and reach a respective point on the map surface by following a straight line, wherein if the ray (ray1, ray2) passes through a non-treatment volume (OAR1, OAR2) or voxel, the intensity of the respective ray (ray1, ray2) is reduced or attenuated by a factor which is determined by the individual feature or attenuation or transparency value of the respective non-treatment volume (OAR1, OAR2) or voxel; and f) generating an intensity distribution on the map surface using the calculated accumulated intensities, wherein the areas or points on the map surface which exhibit the highest calculated accumulated intensity are used to define one or more suitable directions for irradiating the object and/or are used to control the position and/or activation of a radiation device. a) acquiring segmented data of an object which contains a treatment volume and a non-treatment volume (OAR1, OAR2); b) modelling at least some or all of the volume or surface of the treatment volume as a source of light or rays (ray1, ray2) exhibiting a predefined or constant initial intensity; c) modelling the non-treatment volume (OAR1, OAR2) as comprising volumetric elements or voxels which each exhibit an individually assigned feature or attenuation or transparency value (t min ≤ t ≤ t max) for the light or rays (ray1, ray2) which feature is assigned to the light or ray (ray1, ray2) or which attenuation or transparency maintains or reduces the intensity of the light or ray (ray1, ray2) as it passes through the respective volumetric element or voxel, wherein the feature or attenuation or transparency value is individually assigned to each volumetric element or voxel of the non-treatment volume (OAR1, OAR2); d) defining a map surface which surrounds and is outside of the treatment volume; e) calculating an accumulated intensity value for points or areas on the map surface, the accumulated intensity being the sum of the intensities of all the rays (ray1, ray2) which exhibit the predefined or constant initial intensity and are emitted from the volume or surface of the treatment volume and reach a respective point on the map surface by following a straight line, wherein if the ray (ray1, ray2) passes through a non-treatment volume (OAR1, OAR2) or voxel, the intensity of the respective ray (ray1, ray2) is reduced or attenuated by a factor which is determined by the individual feature or attenuation or transparency value of the respective non-treatment volume (OAR1, OAR2) or voxel; and f) generating an intensity distribution on the map surface using the calculated accumulated intensities, wherein the areas or points on the map surface which exhibit the highest calculated accumulated intensity are used to define one or more suitable directions for irradiating the object and/or are used to control the position and/or activation of a radiation device.