R Shiny animation scatterplot speed performance - r

Question

I want to make an animation in R Shiny where my scatter plot is progressively updated at each iteration, here is my current plot
library(shiny)
library(plotly)
ui <- fluidPage(
titlePanel(""),
sidebarLayout(
sidebarPanel(
actionButton("launch", "Launch Simulation"),
radioButtons("display","Show every iteration", selected = 10,
choices = c(1,5,10,50),inline = FALSE),
numericInput("iter","Maximum number of iterations", value = 2000,
min = 500,max = 5000, step = 500)
),
mainPanel(
plotlyOutput('plot')
)
)
)
server <- function(input, output) {
rv <- reactiveValues(i = 0,
df = data.frame(x = -1,y = -1))
observeEvent(input$launch,{
rv$i = 0
rv$df = data.frame(x = runif(5000, min = -1,max = 1),
y = runif(5000, min = -1,max = 1))
})
observe({
isolate({
rv$i = rv$i + as.numeric(input$display)
})
if ((rv$i < input$iter)&input$launch){
invalidateLater(0)
}
})
output$plot <- renderPlotly({
df = data.frame(x = 0,y = -1)
df = rbind(df,rv$df)
plot_ly(df[1:(rv$i + 1),], x = ~x, y = ~y,
type = 'scatter', mode = 'markers',
marker = list(size = 4), hoverinfo="none") %>%
layout(showlegend = FALSE)
})
}
shinyApp(ui = ui, server = server)
The code is working fine at the beginning but after around 1000 iterations, the animation becomes very slow. I think the main problem is that because in my code, I have to re-make the plot all over again at each iteration, is there a smoother way to do what I want to do?
(Not necessarily with Plotly but it is important to me that I keep track of the number of the iterations outside of the plot (here rv$i))