High Realistic Infrared Scene Simulation Based On Ray Tracing

Rational use of infrared imaging simulation technology can improve the efficiency of infrared imaging system design, evaluation and application. This will help shorten the infrared weapons development cycles, reduce development costs and predict the application effect of new technology. The improvements of the performance of infrared weapons require the improvements of the physics realistic of infrared scene simulation. The traditional GPU-based simulation technology simplify the simulation model to ensure the real-time simulation. This technique is only considered reflection of a strong light source such as the sun, bait, etc., ignoring the reflection of other radiation sources. This method is a parallel computing method and not able to calculate occlusion relationship between radiation sources and the secondary reflection. These will seriously affect the realism of simulation. Therefore, the author’s major contributions are outlined as follows:(1) This thesis analyzes the infrared radiation imaging process and establish a reasonable infrared radiation transmission model. All objects are radiation sources in the infrared band, the radiation characteristics of the radiation source is determined by spontaneous emission and reflection to other radiation sources. In this thesis, the spontaneous emission of infrared radiation, reflection, transmission in the atmosphere and infrared imaging effect are considered as a whole process. In this thesis, bidirectional reflectance function is used to describe the reflection of the target object to other radiation sources. In this thesis, the internationally accepted atmospheric radiation transmission model is used to calculate the effect of atmospheric transmission of infrared radiation and infrared imaging system model is constructed.(2) This thesis introduces ray tracing algorithm to simulate radiation transmission process. Ray tracing technique can accurately describe the reflection of infrared radiation. In the infrared, the majority of the radiation source can not be viewed as a point source. In this paper, sampling methods is used to calculated the occlusion relationship between the radiation sources.(3) However, the operation process is quite time-consuming. The most time-consuming process of ray tracing algorithm is seeking intersection of light and scene. All of the objects are radiation sources in the infrared band. Each point must calculate the reflection of radiation source in each direction. This wil l significantly increase the amount of light, seriously affecting the efficiency of the infrared image generation, thereby affecting the application efficiency. We obtain the infrared imaging simulation framework based on ray tracing algorithm. Organization of three-dimensional scenes with reasonable spatial structure is an effective way to improve the efficiency of light traversing the scene. In this paper, KD tree structure is used to organize the scene, and Surface Area Heuristic is used for KD tree segmentation. Each internal node KD tree represents a division of space. The two sub-trees continue to be divided in the same way recursively until it encounters a stop condition.(4) Ray tracing algorithm is applied to infrared radiation transmission simulat ion in this paper. This paper implements the infrared scene image generation with ray tracing algorithm and obtained the result of infrared reflection and shadow. In the end, we validate and analyze the actual measurement results and the simulation results.