Here in this lecture, we'll add a scrolling background to the game. I've imported a background image here, it's a simple border texture. So I'll open the room and go to the Layers panel, I select the background layer. Under the properties, I can select an image for the background, so I'll select the water Sprite. Now you can see that it appears in the room but only once. So I'll go to the properties and enable horizontal and vertical tiling.

Now it fills the room. Now we'll go to properties and scroll down. I'll set the vertical speed to four. So the background will keep going down at four pixels per step. So this way it will give the illusion that the player ship is going forward when it's actually the background scrolling down. So run the game and you can see that the background is moving.

Now let's implement the islands. I started start by creating a new sprite and ultimate s Island click on Import. Now I need to import these four oil and images into one Sprite. So I'll select these four files and click Open. So now we have four frames in our Sprite. Generally multiple frames are used for animations.

So you have a play button here and an animation speed and if you hit the play button and the sprite animators, but we don't need these four frames for animation, we just found any one of these images to randomly show up for the island. So I'll set the animation speed to zero so that the sprite doesn't animate and we'll set the origin to middle center. Now let me explain to you the image index of our Sprite. Image index is a built in variable in objects that stores the number of the frame that is being displayed. So the first frame is zero, the second frame is one and so on. So when we create our island object, we wanted to select a random frame in the zero to three range So I'll create an object called oil and I'll assign the sprite.

Now I'll add the Create event in the actions also a random, I need this get random number action, so I'll drag it in, This action will give me a random number in a rage. So for that range, I'll set the minimum to zero and the maximum two three, I'll change decimal to integer since we don't want decimal values, and in the target, I'll type image index. So this action will return a random number in the zero to three range and then apply it to image index. So the eyelid sisters will get a random frame from us right now in the actions also at speed and they had this set speed action. This action sets the speed of the cluster so that it starts moving or change direction to vertical. Since I won't die it starts to move vertically instead of moving in a specific direction.

I'll set the speed to four So it'll move down at a speed of four. The speed should match the vertical speed in your rooms background. Now I'll click on Add event, go to other and add the outside room event, this event drones when the task goes completely out of the room. So in that case, we want to destroy that instance, if we don't destroy it, then the island instances will keep adding up and increase the memory usage. So I'll search destroy and add the destroy star section here. So basically, the instance will be deleted when it goes outside the room.

Now I'll open the room and go to the Layers panel. I'll click here to create a new instance layer. So basically, this is another layer for placing instances. I'll hit f2 and rename it to islands. Now make sure that it's placed below the instances layer but above the background layer. Now we'll play some Island instances in this case layer.

So the island install cells will appear below the layer share because the islands layer is below the transport layer. Now we'll run the game and you can see that the islands have different images and that they move down. But we also need to make it so that more or less dances are created automatically. So we'll do that in the next lecture.