Design And Research On Fire Evacuation Simulation Of Virtual Teaching Building Based On Unity3D

The teaching building is a public place with high population density and complex structure,when fire happened,it is easy to cause chaotic order and heavy casualties phenomenon,so it is imperative to research the evacuation problem in fire scene.The article selects the first floor of a teaching building as research background,establishes an evacuation model based on the A*(A-Star)path planning algorithm and studies a direct impact on overall evacuation efficiency and safety status of the evacuees under different A* algorithm conditions and total number.First use 3ds Max,Adobe Fuse cc and other major modeling software to create teaching building,character model and import them into Unity3 D,use particle system components on Unity3 D to establish flame and water column model,add collision body module to all models to generate collision detection mechanism,then the whole fire scene is divided into countless small squares by using grid map method,which lays the foundation for the follow-up using A* algorithm to plan escape route,although the planned escape path is the shortest path,the safety of escape personnel is decreased because of too many turning angles and the traditional A* algorithm does not consider the complexity of fire escape scene.In order to solve the above problems,we need complete two tasks: use Bézier curve algorithm to smooth escape path and add appropriate weight value to the heuristic function to further improve A* algorithm heuristic function,in order to master the evacuation efficiency and safe escape of all escape members,the stopwatch timing function and slider component need to be added to the character model to represent the escape time and remaining life value respectively.The fire evacuation simulation experiment is carried out by using the control variable method,First they are divided into eight groups according to the number of evacuees from 30 to 100,then when the number of evacuees is the same,it is divided into three groups according to different A* path search algorithm conditions(standard A* algorithm,standard A* algorithm under path smoothing and improved A* algorithm under path smoothing),the extreme value and average value of escape time and residual life value of evacuees and the distribution of people in different ranges of escape time and residual life value are studied,through the comparative analysis of the data reaches the following conclusions: with the increase of the number of evacuees,after smoothing the escape path and improving the weight of the A* algorithm heuristic function,although the escape time slightly increases by a few seconds,they can safely escape from complex fire environment,so as to reduce their own losses.