Render sprites onto a virtual 640x480 “screen”

Question

I'm making a game, and in part of it, the player uses a computer terminal. I want to draw to a virtual 640x480 screen with pixel precision, and then draw that "virtual screen" to the player's real screen. The end result will not be "pixel perfect" because 99% of people won't play the game at 640x480 -- and, in fact, I want to then go on and add further effects on top of this so it looks more like a CRT display -- but trying to figure out how to do pixel rendering in Unity has proven pretty difficult so far.

Basically I want to render something that looks like this:

onto the screen, where I draw all of the text characters myself (using Sprites? subsections of a Texture?), and then I want to render this "virtual screen" out onto the player's screen. I know RenderTextures are a thing, and maybe that's part of it? I've tried a lot of different things so far and got nowhere, hence why I'm posting here.

Sorry if this is too nooby of a question, I'm an experienced programmer who is relatively new to Unity.

Answer 1

You will want to use Texture2D.SetPixel or Texture2D.GetPixels and Texture2D.SetPixels if you want to blit sprites onto your texture.

You could render your sprites to a RenderTexture. It may be faster but until Unity5 it was a Pro-only feature (which I don't have) so I haven't experimented with it yet. You can't draw individual pixels on the GPU without a lot of complications though anyway, so if that is a requirement then you will need to use Texture2D.

For a 640x480 image, it should be sufficient to just do it on the CPU with Texture2D, even if you update it every frame.

Answer 2

I think Fuzzy Logic answer is best suited for your question (he got my +1), but i'd like to give a naif alternative. You can setup a bunch of Unity objects like quads, text, sprites (call all that TerminalStuff) and use a separate camera (call it terminalCamera) that capture the terminalStuff (perpendiculary). Then set the render output of terminalCamera to a texture In this way you can change your Terminal elements (like moving unity text objects to simulate scrolling text) to simulate terminal activity.