frame = {
let i = 0
const svg = d3.create('svg').attr("width", f).attr("height", f)
const main = svg.append("g").attr('id','main')
let other = d3.select(SVG)
let group = other.selectAll('.corner').clone(true);
main.selectAll('g')
.data(data).join('g')
.attr("transform", ([i, j, r]) => `translate(${i},${j}) rotate(${r})`)
.attr('id', (d,i) => `C2_${i}`)
.append(() => group.clone(true).node())
return svg.node()
}