Translucent material rendering is an essential part of the field of real-time rendering. Transmission rendering relies on the accurate calculation of transmission thickness and is often limited by the complexity of scene models and lighting. This paper proposed a virtual light-based method to calculate the transmission thickness in translucent material rendering. A virtual light was added to the scene, and the sorting algorithm was employed at the virtual light for the depth information of the scene. In calculating the transmission thickness from the real light source to the shading point, it was proposed to take samples on a straight line segment of the world space connecting the two points, calculate the proportion of sampled points inside the object to the total number, which was multiplied by the length of the straight line segment, thus obtaining the estimation. Moreover, in the case of multiple real light sources

in the scene, the sampling-based method could reuse the scene depth information stored in the virtual light. The proposed method could effectively enhance the accuracy of transmission thickness calculation, and reduce the memory overhead caused by the increasing number of light sources. Experiments show that the proposed method can strike a good balance between efficiency, effectiveness, and memory overhead.