Data manipulation/transformation

Data in CoppeliaSim can transformed in various ways:

Following example illustrates how to pack/unpack data. Other functions can be found here:

#python

# Refer to the various Python packages, e.g.:
import struct
import base64
import cbor2 as cbor

# One can also use some built-in functions:
base64Buffer = sim.transformBuffer(binaryPackedData, sim.buffer_uint8, 1, 0, sim.buffer_base64)
originalBuffer = sim.transformBuffer(base64Buffer, sim.buffer_base64, 1, 0, sim.buffer_uint8)

# Packing/unpacking random data, in CoppeliaSim format:
data = [1, 'hello', {'value': 'world'}, [1, [2, 3]]]
binaryPackedData = sim.packTable(data)
data = sim.unpackTable(binaryPackedData)

--lua

-- Packing/unpacking specific type of data:
local data = {1, 2, 3}
local binaryPackedData = sim.packDoubleTable(data) -- binary packing
data = sim.unpackDoubleTable(binaryPackedData) -- binary unpacking

base16 = require('base16')
local base16PackedData = base16.encode(binaryPackedData) -- base16 encoding
binaryPackedData = base16.decode(base16PackedData) -- base16 decoding

base64 = require('base64')
local base64PackedData = base64.encode(binaryPackedData) -- base64 encoding
binaryPackedData = base64.decode(base64PackedData) -- base64 decoding

local base64Buffer = sim.transformBuffer(binaryPackedData, sim.buffer_uint8, 1, 0, sim.buffer_base64)
local originalBuffer = sim.transformBuffer(base64Buffer, sim.buffer_base64, 1, 0, sim.buffer_uint8)


-- Packing/unpacking random data:
local data = {1, 'hello', {value = 'world'}, {1, {2, 3}}}
local binaryPackedData = sim.packTable(data) -- binary packing
data = sim.unpackTable(binaryPackedData) -- binary unpacking

cbor = require('org.conman.cbor')
local cborPackedData = cbor.encode(data) -- cbor encoding
data = cbor.decode(cborPackedData) -- cbor decoding

More packing/unpacking functions can be found here.

Following example illustrates usage of linear algebra functionality:

#python

# Refer to the numpy package for instance:
import numpy

--lua

-- Get the absolute transformation matrices of an object and its parent:
local absObj = Matrix4x4:frompose(sim.getObjectPose(objectHandle))
local absParentObj = Matrix4x4:frompose(sim.getObjectPose(parentHandle))

-- Compute the relative transformation matrix of the object:
local relObj = Matrix4x4:inv(absParentObj) * absObj

-- Get the relative transformation matrix of the object directly:
local relObj2 = Matrix4x4:frompose(sim.getObjectPose(objectHandle, parentHandle))

-- Check that both matrices are same:
print(relObj:sub(relObj2):abs():max())

The documentation for the linear algebra functionality for Lua can be found here.