Sprite crash or interaction detection SpriteBlock or Pixel perfect?

[Giles N]

It would be really nice to know if the detection between sprites in games (we could also discuss interaction with backdrops), are dependent on

1) Spriteblock coming into contact with other SpriteBlock (entire square 16x16, 32x32 etc),

    or 

2) whether it is the drawn pixels within the sprites that makes for ‘crash-detection’/interaction-detection

    or

3) whether it is the programming behind that matters.

 

- - -

 

I’m primarily concerned with 2D games, not 3D games (driving/fligth).

 

But any input is welcome.

 

Thanks in advance for any info, input, experience.