Encoding and decoding of acoustic environment

An apparatus for decoding an acoustic environment, the acoustic environment comprising at least one audio source and at least one audio object, the at least one audio object being represented by a structural-acoustic data which links positional data of polygons with acoustic properties of acoustic materials, wherein the positional data comprises, for each polygon, the position of the vertexes, the apparatus comprising:

• a bitstream receiver for receiving, from the bitstream, an encoded version of structural-acoustic data and at least one audio stream to be rendered as generated by the at least one audio source in the acoustic environment;
• a processor configured to decode the at least one audio stream representing the at least one audio source,
• wherein the processor is configured to decode the structural-acoustic data,
• wherein the processor uses, for at least one dimension, an ordered shortlist, in which coordinate values of previously decoded vertexes are stored according to an order,
• wherein the process is configured, in case the bitstream has encoded therein an ordinal value of the ordered shortlist, to reconstruct the coordinate value as the value stored in the ordered shortlist associated with the ordinal value,
• the apparatus further comprising a renderer, to render an audio signal obtained from the at least one audio stream according to structural and positional relationships between the at least one source and the decoded structural-acoustic data.