Load PNG Into Sprite & Then Draw Sprite Onto Screen?

Hi,

How would we load a PNG into a sprite and then draw the sprite onto the screen?
A simple C# code example would be appreciated, thanks!

 

Are you talking about a sprite for the UI or for something like a 2D environment?
Unity has some awesome video tutorials that get you started on both areas.

About sprites (for 2D suff)
https://unity3d.com/learn/tutorials/topics/2d-game-creation/sprite-type?playlist=17093
and rendering the sprite on the screen.
https://unity3d.com/learn/tutorials/topics/2d-game-creation/sprite-renderer?playlist=17093

and using a sprite in the ui
https://unity3d.com/learn/tutorials/topics/user-interface-ui/ui-image?playlist=17111

 

Hi,

We have looked through the API documentation
but don't see a function that would load a PNG into a sprite
and another function to display sprite on the screen?
(we want to do everything in code)

Can someone give us a URL to the above in the API documentation?
Thanks!

 

If you're using Unity's native sprite system and not an external 2d library or framework then you don't really get clean code-based api access to the spritesheets. You'll have to do some plumbing with the 2d pipeline and spritesheet metadata that Unity creates for you during builds and the 2d materials if you want to mess with sprite references like that. Instead, to easily reference sprites from spritesheets just make Sprite variables in your behaviours and drop sprite references onto them.

You can load textures at runtime;
https://docs.unity3d.com/ScriptReference/Texture2D.LoadImage.html
https://docs.unity3d.com/ScriptReference/Texture2D.LoadRawTextureData.html

You can pack textures into spritesheets;
https://docs.unity3d.com/ScriptReference/Texture2D.PackTextures.html

You can blit graphics onto the screen using the low-level graphics apis like;
https://docs.unity3d.com/ScriptReference/Graphics.Blit.html

You should take a look at other code-based sprite systems if you want to see how they approach things. Check out something like Futile: https://github.com/MattRix/Futile


From this and a few of your other questions, you should probably re-read the official Unity manual and scripting reference, go through the various tutorials, and get a good c# reference to help you out with the language. At the moment you seem to be approaching Unity at a very low-level, wanting to control framerates, load raw sprite data, have a single 'main' entry point, and done all in code.

Sure, you can sort of work like this if you set up some systems and wrappers and it might work fine for you, but I'd recommend first learning and using Unity the way they encourage you to use so you know what you're dealing with. As others have mentioned in some other replies to you, Unity uses a component-based architecture and has a very modular and editor-based approach to building scenes and adding logic. Your approach is immediately going against this intended workflow. If you want to go against it (and no one's stopping you!) then learn a bit about how it all works first

 

Are you wanting to load the sprite at runtime for some reason? Or are you just wanting to use a sprite?

If you are just wanting to draw a sprite on the screen (and have it move around), do the following:

With a new project:

1. drag your PNG file into the assets folder.
2. select it, and in the inspector, change the texture type to "Sprite"
3. right click in the scene hierarchy, and choose UI/Image. This will create a Canvas, an EventSystem and an Image (under the Canvas).
4. Click on the image in the Hierarchy. On the "Image" script, rename it to "MySprite" or something like that. On the image component, assign the sprite you created by dragging it from the project window and dropping it on the field that has the "Source Image" label.

if your scene view is not in "2d" mode, press 2d on the scene toolbar, and then zoom out to see your sprite.
you can reuse this by making it a prefab.

If you are wanting to dynamically load the sprite, then usually you create a "Resources" folder, and place your PNG in that folder. Be sure to set the type as Sprite. Then you can load the sprite using Resources.Load<Sprite>("PngFileNameWithNoExtension");

 

Thank you so much.

 

2. select it, and in the inspector, change the texture type to "Sprite"

I wouldn't have clicked on it if it hadn't been for you... would be wondering why my png's just don't import!

 

I don't think this works for if the image itself isn't downloaded until runtime?