Abstract: From the volume fog algorithm, the smoke is rendered in the virtual reality space based on the extinction formula, so that the extinction effect is close to that of the non-irritating real smoke in experiments. This research provides effective support for the simulation of emergency exit instruction system in virtual space. This work also tested the impact of 1 080 and 1 440 resolution head-mounted VR display on human visual acuity and visibility. The experimental results show that the low resolution in VR helmet reduces the visual acuity, but has not much impact on visibility. In virtual dark scenes, the improved volume fog algorithm can bridge the gap between human visibility and smoke extinction coefficients, so as to test the visual perception effect of human eyes on fire smoke. The relationship between human eye visibility and fire extinction coefficient is constructed, and it provides a means to reconstruct the smoke in a VR environment based on the simulation result from FDS, which can improve the effect of escape drill in virtual fire field.

Key words: virtual reality｜, volumetric fog technology;fire visibility, virtual smoke reconstruction, FDS