Blogs - AlexPetrus

In video games I often see camera effects while playing. E.g. twisting the camera or distort the image of it. But how can you apply an effect like shaking to the camera? But first we have to understand what the camera in a video game is and what it does.

What is the camera and what does it in my game?

At first i want to explain what the camera in a video game is and what it does. While developing a video game you have to use a camera at some point. At least for most engines you have to. I started coding for games with LWJGL and if you want to use a camera there, you have to code it by yourself. Currently I'm programming with libGDX that also uses a camera for rendering the game. The camera is in fact the essential part of you game that provides data for you graphics card to be rendered on your screen. So without the camera in your game you wouldn't see anything.

But what how does it do that? That doesn't really matter, we just have to understand what the in general does and how we can use it. In general the camera has a specific position, direction and viewport. Position and direction just mean where the camera is and in what direction it is looking. The viewport is the size of the viewable field the camera has, mostly also the size of the images sent for rendering. We can also imagine this as a viewable field.

How to apply a shake effect to the camera:

Before we can apply any effect to the camera we have to think about the effect. In this case we want to shake the camera a bit. For the camera shaking means you change its position slightly to a given origin. Lets say the given origin is the actual camera position and we just want to create a small offset for that position and add it to the origin values to change them a bit. So the only thing for us to do is to calculate the offset for a shaking.

But is it only done by changing the position? No, you also can change just the angle with a similar method, or both. All three possibilities will give a different effect but all like shaking.

So, how can we calculate the shaking? That's not an easy question because there are several ways to to that. For example you could use a generated noise that lowers its intensity over time and apply that to the origin, or you can use a complex algorithm ... But lets say we want to keep it simple and clean. I decided for my self to generate a random number and use this to calculate two values between 0 and 1 that I use for a vector. Vectors in general are used for positions and directions and are handy because of the math you can do with them. Later I limit the length of the calculated vector and just add it to the actual camera position. Below you can see an excerpt of the code I use:


1. camPosition = player.getPosition();
2. if(shakeTime < .3f && player.getHP() > 0f){
2. double offset = Math.random() * 6.28;
3. Vector2 shake = new Vector2((float) Math.sin(offset), (float) Math.cos(offset));
4. shake.limit(Interpolation.fade.apply(.1f,0f,shakeTime));
5. camPosition.add(shake);
6. }


Explanation:

1. Get the actual camera position.
2. Only calculate if player is alive and the time for shaking is big enough
3. Calculate a random number from 0 to 2π.
4. Generate a vector with x and y value between 0 and 1.
5. Limit the vector with a fade out interpolation.
6. Apply it to the actual camera position

If you want to see the effect in motion feel free to check the video at my homepage.

This small tutorial is also applicable for other position changing effects for all sorts of things done with vector in a video game. E.g. you could use it for the changing the players position because of an effect from a bad potion or changing the light intensity of a torch.

Today I got inspired by a post in a post in a Facebook group. A fellow developer was asking for advice about animating sprites and software that everyone uses. So I thought how I started creating sprite animations and wrote an article on my website.

Here is the link to the article .

I wish some people searching for a point to start find that inspiring.

The last week I thought about some things I want to get ready before I start with generating levels. One of this things were collectable/consumable items.

Here is the link to my post: Alexpetrusdev.de

Below you can see some footage of my work in progress.

As planned I created some footage to show you the current development state of The Cursed Iron Cavern. I want to create a retro looking game with a rather dark setting but not like in horror games. So what do you guys think about it?

You also can download an test a version of my game at Alexpetrusdev.de

Happy testing!!!

So my dear readers, I’m really proud about the news I have to tell you. Last night my page got a brand new Download Area. Here you will find the latest versions of my projects, especially my current game The Cursed Iron Cavern.

But there is also an other reason I made CIC downloadable, I need feedback from you. So please download and install the latest version of CIC and send me some feedback.
You can use my contact form, send me a message via Facebook, Twitter or Ello or just send me a mail. I would really appreciate it if I get your feedback.

After a reativly long break because of illness I'm lately working on my game The Cursed Iron Cavern again. During the last time I made some plans for enemy life cycle and attack and started implementing those. You can read more on my website alexpetrusdev.de about it. But I want to give you some material as well:

So there I am, this is my first post in IndieDB.

Only a short time ago I lauched my page Alex Petrus Developments. From there I share all my work in game development. Currently I'm working on a game called The Cursed Iron Cavern (CIC). It's my first game project and going pretty well. Currently I'm working all alone on CIC and I have to admit that it's really hard work designing and creating a game.

If you want to read more about CIC feel free to visit my page Alex Petrus Developments where I'm also bloging about latest features of my current project. If your into social networking, I'm also on Twitter: @the_1_alex and running a page on Facebook: facebook.com/alexpetrusdev .

Below you can finde some images and videos of CIC.