Adding Two Dimensional Data Protocols for python wrapper (vtx & tex)

[baptiste-mnh]

Relating to this issue :
https://github.com/erleben/pySoRo#adding-two-dimensional-data-protocols

I add two function in the python wrapper to get the vertices and textures coordinate compatible with open3d to do real time visualisation.

The 2 new functions

points.get_vertices_2d()
points.get_texture_coordinates_2d()

The code to test :

import pyrealsense2 as rs
import numpy as np
from open3d import *


# Create a pipeline
pipeline = rs.pipeline()

# Create a config and configure the pipeline to stream
#  different resolutions of color and depth streams
config = rs.config()
config.enable_stream(rs.stream.depth, 640, 480, rs.format.z16, 30)
config.enable_stream(rs.stream.color, 640, 480, rs.format.rgb8, 30)

# Start streaming
profile = pipeline.start(config)


# Streaming loop
try:
    vis = Visualizer()
    vis.create_window("Test")
    pcd = PointCloud()
    while True:
        vis.add_geometry(pcd)
        pcd.clear()
        # Get frameset of color and depth
        frames = pipeline.wait_for_frames()
        color = frames.get_color_frame()
        depth = frames.get_depth_frame()
        if not color or not depth:
            continue
        pc = rs.pointcloud()
        pc.map_to(color)
        points = pc.calculate(depth)
        vtx = np.asanyarray(points.get_vertices_2d())
        pcd.points = Vector3dVector(vtx)
        vis.update_geometry()
        vis.poll_events()
        vis.update_renderer()
finally:
    pipeline.stop()

[dorodnic]

Hi @baptiste-mnh
At glance looks very cool, thank you for contributing!

[lramati]

The pull request's logic is great, but there's a couple small things that could add some more polish.

[lramati]

It would be nice if this wasn't hard coded to floats.
It should be enough to add the std::string &format and size_t size parameters from the above overload and use them instead of "@f" and sizeof(float) respectively.

[lramati]

I think it would be cleaner to have a single get_vertices function that takes an int parameter requesting the number of dimensions of the output than get_vertices and get_vertices_2d.
This function should default to 1 dimension on no input to remain backwards compatible.

[lramati]

Same here as on get_vertices_2d

[baptiste-mnh]

Thanks!
So how do you call it when you want in in 2D?

[lramati]

Whatever you think looks most pythonic. get_vertices(2) or get_vertices(dims=2) seem like reasonable choices.

[baptiste-mnh]

Yes I approve this choice!

[dorodnic]

This PR should get auto-merged once we make this weeks release and merge development into master