DEV Community: David Asamonye

Virtual Reality and Augmented Reality — Different or Similar?

David Asamonye — Tue, 22 Oct 2019 08:48:01 +0000

The more I delve into Virtual and Augmented Reality, the more excited I am about these fields of study and the more I become more dedicated to exploring them both. Today, we will not go over how to get started with building Virtual Reality or Augmented Reality, we will cover that in another article, this is more like an introductory article to the two concepts.

For the sake of newbies, I would go over defining the basics of both Virtual and Augmented Reality.

What is Virtual Reality?

Virtual Reality is a simulation of a virtual world, sort of like an alternate universe, where the user sees and hears an experience that is created by man. It gives you a feeling of immersion into the game or movie that is being experienced.

What is Augmented Reality?

while Virtual Reality is a simulated virtual world, Augmented Reality is the superimposition of virtual objects on the real world, In Augmented Reality, you are still conscious of the real world around but with the insertion of virtual objects, which through several techniques, look and act as though they are present in the real world.

To the beginner, both may be hard to tell apart, most especially if one has not had any experience of both but the more you learn about them, the further apart they grow in your mind.

The truth is, they share some similarities but from my experience, they are a lot more different than they are similar both in terms of experiencing them and most especially the techniques and technologies that are used to build them.

Similarities

The major similarity between VR and AR is the fact that both have to deal with virtual objects meaning that whether you are working on a VR project or an AR project, you would either have to create your own “Game” objects or import already existing objects into your project and for the most part, you may have to do so using a Game engine such as Unity or Unreal Engine or build your Objects from scratch.

Differences & Unique Challenges

The differences of both lie in the way they have to be presented to the end-user, VR is basically a simulation, meaning that as a creator, you must be able to give your user the feeling that the experience is real, for this to happen, the VR device should be powerful enough to deliver consistent high framerates, as any drop in framerates would break the immersion.
Virtual Reality is all about convincing a user that the virtual world he is experiencing at the moment is no different from the real world, right now, there are some limitations in achieving this goal namely;

The two lenses used for each eye magnifies the screen which makes the view in most VR devices pixelated.
For there to be an illusion of reality, all the human senses must perceive something similar, imagine you are feeling cold while your eyes can see fire all around, this makes it difficult to be convinced that the experience is real. Another example is you enjoying a fast-moving VR experience while you are sitting on the couch in your living room, as a matter of fact, this causes a very popular problem with VR today called Motion sickness, this just basically means that what the body sees is not in tandem with its sense of movement.

There are still other limitations to achieving the illusion of reality in VR but I believe these are the major challenges. It is important to note that regardless of these challenges, VR is still a very enjoyable experience and if you haven’t tried it, I urge you to give it a try, you will not regret it.

For Augmented Reality, the user doesn’t have to be convinced that the experience is real, the main challenge in AR is for the user to feel as though the virtual objects are part of the real world. What this means is that the virtual objects must properly overlap the real world, that is, if you added a virtual dog to stand on the ground, the dog must be seen as standing on the ground, if the dog is perceived to be floating, the experience would appear unreal.

Another challenge has to do with lighting, imagine being in a poorly lit room and then you introduce a virtual object into the environment and the virtual object looks really bright, it will appear unreal also, the virtual object has to be lighted according to the room lighting both in terms of amount and the source direction.

One other challenge with AR is something called Occlusion, I will explain with an example. Suppose you place a virtual cup on a distant table, let’s assume the cup properly overlaps and sits on the table and the lighting was correct, imagine that someone walks in between you and the table and you still get to see the cup even while there is an obstacle(the human subject), the makes the experience appear fake, I do believe it is quite challenging because it involves the AR device to be able to sense depth and arrange objects based on their proximity, also, suppose the subject in between the virtual object and the AR device is transparent, the AR device should make an exception to that.

Conclusion

The fields of VR and AR are really exciting areas of exploration, a lot has been achieved but a lot more still needs to be achieved. Currently, there are SDKs and other tools that try to tackle the challenges that are unique to VR or AR but they are not yet perfect. This is going to be our first article in a series based on building VR and AR experiences, our next article will be an introduction to the tools and technologies used in building both VR and AR experiences, so stay tuned for that!

Performing Binary Search in JavaScript and Ruby

David Asamonye — Mon, 14 Oct 2019 09:40:40 +0000

Binary Search is arguably the most effective means of searching through very large data to find a target value. It does by eliminating half of the data each time it traverses through to find the target. For example, if you were to search through 1–20 to find 11, how would you do that? the first reaction would be to search linearly by counting from 1 till you find 11, you won’t notice how tasking this can be until you are searching for 1,123,000 out of 2,000,000 numbers but you can greatly simplify this process using binary search. If we are to find 11 from 1–20 using binary search, all we have to do is get the value in the middle i.e. 10 and we compare with 10 with our target value, since 11 is greater than 10, we then eliminate every value from 10 downwards, then we get the middle value once again between 10–20 i.e. 15 then compare with 11, now 11 is less than 15, so in the case, we eliminate all values from 15 upwards, we keep repeating this step until we find the target value. Again, since the dataset (1–20) is small, we may not notice how time and effort saving binary search can be until you search a very large set of data.

Binary search becomes more effective with increase in data. For instance, we would require a lot less steps while searching for 1,123,000 among 2,000,000 numbers compared to linear search than we would search for 11 among 20 numbers. Let’s run a pseudocode to see how many steps it will take us to search for 19 among 30 numbers;

First, we set our default min and max values to 0 and array.length i.e. 29 respectively.

min = 0
max = 29

Get the average of the min and max values and set it to a variable of your choice, let’s call ours search. Remember to round search to the nearest whole number.

search = (0+29)/2 = 14.5 ~ 15

Compare search to the target value 19, if search = 19, then we have found our answer, if not, we can proceed. In this case, search is not equal to 19.

if search == targetValue
    return search

If search is less than targetValue, we set min = search + 1. Since search, 15, is less than targetValue, 19, we set our min = 15+1=16.

if search < targetValue
    min = search + 1

Next, we recalculate our search variable, i.e. (16+29)/2 = 45/2 = 22.5 ~ 23. Remember, we always round off search.

search = (16+29)/2 = 22.5 ~ 23

Compare search to target value once again, as before, if search == target value, we simply return search. In this case, search is greater than the target value.

if search == targetValue
    return search

If search is greater than targetValue, we set max = search -1. i.e. max = 23–1=22.

if search > targetValue
   max = search - 1

Once again, we recalculate our search value, i.e. (16+22)/2 = 38/2 = 19.

search = (16+22)/2 = 38/2 = 19

Compare search to target value once again, as usual, if search==targetValue, we have found our answer. Here, search == target meaning, we found our answer! So we return search.
Lastly, if none of the above conditions are met, we set the function to return -1.

It took us 9 steps to search for our target value among 30 numbers, if we were to count linearly, it will take about 19 steps to do the same, so now you can see how effective Binary search is.

Now, we are going to translate our pseudocode into real-life code in JavaScript and Ruby so we can better appreciate Binary search:

Ruby Implementation

JavaScript

Conclusion

One very important thing to note about performing a Binary search is that you slice the array in half each time you perform a search. In our code above, we made an iterative solution for solving Binary search, you could also solve the problem using recursion if you want to. The true power of binary search lies when you have millions probably billions of elements to search through, it is also a widely used method for search in Computing.

Linked Lists in JavaScript and Ruby

David Asamonye — Thu, 26 Sep 2019 09:53:12 +0000

A Linked List is a linear data structure similar to an Array, Queue or Stack where each element called a Node is organized sequentially and each Node contains data of its value and a pointer or reference to the next Node. If you remember while we were kids in primary and even secondary school, we always had a general students assembly each morning where we placed our hands on our neighbours shoulders, recall that our only concern at that point was ourselves(node.value) and then our hands resting on the shoulder of the person next to us (next_node), this should give us a practical example of what a Linked List looks like.

So far, we have only discussed a Linked List where we only have a reference to the Node in front of us, what about a situation where we also want to keep have a pointer to the Node behind? This is where Doubly Linked List comes in, in Doubly Linked List, each node has three information, its value, a reference to the next node and also a reference to the node before it, meaning it is possible to traverse either forward or backwards in a Doubly Linked List.

As a Microverse student, the three first coding challenges in the Ruby curriculum are based on Linked Lists, while you are only required to solve these challenges in Ruby, I made an extra effort to see what it looks like to implement a Linked Lists and some of its methods in JavaScript. So let’s get started!

First, let us create a sort of mockup for our Linked List in a sequential order (pun intended);

Define the Node class
Define the Linked List class
Create add method

Define the Node Class
First, we must define a Node object that would have a data value and also contain a reference to the next_node, remember that a Node in a Linked List is simply each element in the Linked List.

Ruby Implementation

JavaScript

We set next/next_node to nil/null by default just in case no value is passed as an argument e.g when the current node is the last. We can also see that our node object has two properties.

Define the LinkedList class
The next thing on our mockup list is to create a LinkedList class, this will contain the head which is the entry point into our Linked List, tail which is the end of the List. The LinkedList class should house the methods we will create.

Ruby Implementation

JavaScript

In Ruby, we also add a class variable list_length which will be useful in creating some of the methods.

Create add method
Now that we have set up our Node and LinkedList class, the next thing we are going to do is to create an add method that will allow us to add new nodes to the end of the list. To achieve this, we will move(traverse) through the list to the end of the list find the tail node, then instead of the tail node pointer to point to null, we make it point to the newly created node.

Ruby Implementation

JavaScript

Conclusion
That is all for today, we have been able to create both the Node and LinkedList class and also create a method to add new nodes to the end of the list.

How did you learn to create Algorithms to solve problems?

David Asamonye — Tue, 11 Jun 2019 10:16:26 +0000

This is my first post on this amazing platform, I am not yet an expert coder and I am seeking some inspiration from the experts in the house.

Kindly share your experience of becoming proficient enough to tackle challenges or problems using code of your preferred language.

I would love to hear all your wonderful experiences, I am pretty sure this would help others also.