BackgroundPetrochemical products possess a high risk of flammability, explosivity, and toxicity, making petrochemical accidents exceedingly destructive. Therefore, disaster analysis, prediction, and real-time simulations have become important means of controlling and reducing accident hazards. MethodsThis study proposes a complete real-time simulation solution of gas diffusion with coordinate and concentration data, which was mainly aimed at simulating the types of harmful gas leakage and diffusion accidents in the petrochemical industry. The rendering effect was more continuous and accurate through grid homogenization and trilinear interpolation. This study presents a data processing and rendering parallelization process to enhance simulation efficiency. Gas concentration and fragment transparency were combined to synthesize transparent pixels in a scene. To ensure the approximate accuracy of the rendering effect, improve the efficiency of real-time rendering, and meet the requirement of intuitive perception using concentration data, a weighted blended order-independent transparency(OIT) with enhanced alpha weight is presented, which can provide a more intuitive perception of the hierarchical information of concentration data while preserving depth information. This study compares and analyzes three OIT algorithms—depth peeling, weighted blended OIT, and weighted blended OIT with enhanced alpha weight—in terms of rendering image quality, rendering time, required memory, and hierarchical information. ResultsUsing weighted blended OIT with an enhanced alpha weight technique, the rendering time was shortened by 53.2% compared with that of the depth peeling algorithm, and the texture memory required was significantly smaller than that of the depth peeling algorithm. The rendering results of weighted blended OIT with an enhanced alpha weight were approximately accurate compared with those of the depth peeling algorithm as the ground truth, and there was no popping when surfaces passed through one another. Simultaneously, compared with weighted blended OIT, weighted blended OIT with an enhanced alpha weight achieved an intuitive perception of the hierarchical information of concentration data.