 Animation director Toshihiko Nishikubo was responsible for the realism and strove for accurate depictions of movement and effects . The pursuit of realism included the staff conducting firearms research at a facility in Guam . Nishikubo has highlighted the tank scene as an example of the movie 's realism , noting that bullets create sparks when hitting metal , but do not spark when a bullet strikes stone . 
 Animation director Toshihiko Nishikubo was responsible for the realism and strove for accurate depictions of movement and effects . The pursuit of realism included the staff conducting firearms research at a facility in Guam . Nishikubo <a href='been_done' title='1'><mark>has</mark></a> highlighted the tank scene as an example of the movie <a href='null_genetive' title='2'><mark>'s</mark></a>realism , noting that bullets create sparks when hitting metal , but do not spark when a bullet <a href='uninflect' title='3'><mark>strikes</mark></a> stone . 
Animation director Toshihiko Nishikubo was responsible fa da realism and strove ffaaccurate depictions of movement and effects . Tdapursuit of realism included the staff conducting firearms research at a facility in Guam . Nishikubo done highlighted thdaank scene as an example of the movie  realism , noting that bullets create sparks when hitting metal , but do not spark when a bullet strike stone .