I am having trouble showing the back$\_$plane. All the other plances work without an issue. The output shows an image and not an animation. Please help

$"""$ We will use a scene dictionary with keys as object names

Each object will have its own keys containing object$-$specific points and transformation matrix"""

# $3-$D$,$ unit$-$cube $($homogenous coordinates$)$

cube $=$ np$.$array$([[0,0,0,1],[1,0,0,1],[1,1,0,1],[0,1,0,1],$

$[0,0,1,1],[1,0,1,1],[1,1,1,1],[0,1,1,1]])$

# make length of the cube $12$ meters

cube$[$:$,$ :$3]=12*$ cube$[$:$,$ :$3]$

cube$[$:$,$ :$3]=$ cube$[$:$,$ :$3]-6$

$...$#scene$[\text{'}$back$\_$plane'$][\text{'}$transform$\text{'}]=$ np$.$array$([0,0,0,-$height $/2,-30,$ Z$\_$start $+$ height$])$

scene$[\text{'}$back$\_$plane'$][\text{'}$transform$\text{'}]=$ np$.$array$([90,0,0,-$height$/2,-30,$ Z$\_$start$])$

# create and transform the cube

scene$[\text{'}$cube$\text{'}][\text{'}$points$\text{'}]=$ cube

scene$[\text{'}$cube$\text{'}][\text{'}$transform$\text{'}]=$ np$.$array$([30,30,0,0,0,$ Z$\_$start$])$

$"""$ Perform the dolly of the entire scene, save images as a single gif $"""$

## TODO Create the Z values for the dolly animation

## store Z values in a numpy array object of size $[$steps$]$

Tzs $=$ np$.$linspace$($Z$\_$start, Z$\_$end, steps$)$

## TODO Compute the focal length to keep the cube of same size

## store the f values for each Z step in a numpy array object of size $[$steps$]$

## this f value should be adjusted to keep the cube the same size throughout the animation

#fs $=$ f$\_$start $*($Tzs$[0]/$ Tzs$)$

$...$ # visualize the scene

plot$\_$img $=$ visualize$\_$scene$($projected$\_$scene, grid$\_$count$)$

# write the current image in the gif

gif$\_$writer.append$\_$data$($plot$\_$img$)$

gif$\_$writer.close$()$