Method for processing an optically reactive material, with: - Providing a starting material that is optically reactive and fills in a working volume arranged in a receiving vessel; and - optical processing of the source material in the working volume by irradiating light of a first wavelength and light of a second wavelength differing from the first wavelength, wherein the light first wavelength and the light second wavelength are provided by an illumination device and by means of optical processing at least one material property of the starting material is changed and the optical processing comprises the following: - Irradiate a first layer part volume of the working volume filled with the starting material with the light of the first wavelength; - Irradiate the first layer part volume of the working volume with the light second wavelength, wherein the light second wavelength is projected only the first layer part volume in whole or in part into the working volume by means of a projection device; - Irradiate a second layer part volume of the working volume filled with the starting material, which is different from the first layer volume, with the light of the first wavelength; - Irradiating the second layer part volume of the working volume with the light second wavelength, wherein the light second wavelength is projected only the second layer volume in whole or in part into the working volume by means of the projection device; and - Repeat the preceding steps for layerwise optical processing of the starting material in the working volume up to a volume of the starting material to be processed, which captures the working volume in whole or in part, is optically processed, characterised in that the light first wavelength is irradiated by means of several light generators for the generation of a light section, which radiate from different sides of the receiving vessel into the working volume and generate by superimposing partial beams the light section in which the projection takes place. - Providing a starting material that is optically reactive and fills in a working volume arranged in a receiving vessel; and - optical processing of the source material in the working volume by irradiating light of a first wavelength and light of a second wavelength differing from the first wavelength, wherein the light first wavelength and the light second wavelength are provided by an illumination device and by means of optical processing at least one material property of the starting material is changed and the optical processing comprises the following: - Irradiate a first layer part volume of the working volume filled with the starting material with the light of the first wavelength; - Irradiate the first layer part volume of the working volume with the light second wavelength, wherein the light second wavelength is projected only the first layer part volume in whole or in part into the working volume by means of a projection device; - Irradiate a second layer part volume of the working volume filled with the starting material, which is different from the first layer volume, with the light of the first wavelength; - Irradiating the second layer part volume of the working volume with the light second wavelength, wherein the light second wavelength is projected only the second layer volume in whole or in part into the working volume by means of the projection device; and - Repeat the preceding steps for layerwise optical processing of the starting material in the working volume up to a volume of the starting material to be processed, which captures the working volume in whole or in part, is optically processed, characterised in that the light first wavelength is irradiated by means of several light generators for the generation of a light section, which radiate from different sides of the receiving vessel into the working volume and generate by superimposing partial beams the light section in which the projection takes place. - Irradiate a first layer part volume of the working volume filled with the starting material with the light of the first wavelength; - Irradiate the first layer part volume of the working volume with the light second wavelength, wherein the light second wavelength is projected only the first layer part volume in whole or in part into the working volume by means of a projection device; - Irradiate a second layer part volume of the working volume filled with the starting material, which is different from the first layer volume, with the light of the first wavelength; - Irradiating the second layer part volume of the working volume with the light second wavelength, wherein the light second wavelength is projected only the second layer volume in whole or in part into the working volume by means of the projection device; and - Repeat the preceding steps for layerwise optical processing of the starting material in the working volume up to a volume of the starting material to be processed, which captures the working volume in whole or in part, is optically processed,