How to create links between nodes for an RRT planner?

Hi Community,

I have started my journey on learning about path planning algorithms where I have referred some very useful videos over youtube especially Brian douglas Explanation, In order to deduce my observations I wish to animate the node links being generated just like in the video but I am unable to do so.

Here is what I have achieved so far RRT Planner (only the nodes being generated and not the links).

Can someone please help me out here such that I could animate in a similar way for other path planning algorithms in the future?

[Ajay Pattassery]

Hi,

I had a look at the code and it is animating the nodes. Could you clarify on what you mean by animating node links.

[Swarup Tripathy]

By node links, I mean the line joining two nodes i.e., in case of RRT, a line joining the random node generated with it's nearest node.

With the links I wanted to have a better understanding for the formation of path planning.

Answer 1

[Swarup Tripathy]

To give an update, originally I had asked this question on StackOverflow and with the help of a person whom I connected on Matlab Discord server. I could finally generate the node links:

Here is the stack overflow link: Animating RRT node links

Final output

In the code if you tune around the part of code below present in the for loop

pause(0.4)

You'll observe the formation of nodelinks between 2 nodes and have a better understanding.

Answer 2

[Sakshay]

Hello Swarup,

As per my understanding, you want to animate the plotting process of the lines (called links in your case) that you are generating.

For animating the plot of a line, the "animatedline" object. An example code for animating a line would be:

% Create animatedline object
h = animatedline("Color", "green");

% Define the limits of the plot
axis([-20 20 -20 20]);

% Example Data
x = [1:0.05:10];
y = [1:0.05:10];

% Iteratively add points to the line object
for k=1:length(x)
    addpoints(h, x(k), y(k));
    drawnow
end

The more points in the data, the better the animation would look. Please refer to the following documentation for more information on the same:

Create animated line - MATLAB animatedline (mathworks.com)

[Swarup Tripathy]

I am not sure if this would be helpful in this case since RRT connects the nodes with the nearest node present.