This study investigates the influence of light types and intensity on spatial brightness perception in virtual reality (VR). Spatial brightness is the result of the complex relationship between the luminance of an object and its surrounding environment. Four experiments were conducted using different types and intensities of virtual light sources in a VR environment, where the observers were asked to match the brightness of a test scene to a reference scene. The results show that different light types, such as spot, point, and rect lights, affected the perceived spatial brightness differently. The existence of an object on a vertical surface had insignificant influenced the spatial brightness perception. The order of reference light intensity and the presence of shadows also had little impact on the brightness matching. Experimental results show that light types and intensity are important factors for creating realistic and immersive VR experiences. At the end of the thesis, directions for future research in this area are recommended.

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