Cheat Engine

[flarn2006]

I made a cheat table for Sonic Adventure 2 with all kinds of Lua features, like an object spawner. I'd like to make it so I can spawn objects by clicking where I want to put one, or click on an object to select it. Something to do the opposite would also be nice, so I could put a little mark on the currently-selected object. Is there any way to do this? If not, take this as a suggestion.

[Dark Byte]

This is something you need to implement yourself
First you need to find the projection, view and world matrix used by the game (game specific)
Then use that to project a vector from screenspace into object space and follow that vector

Then you need to build a list of all the objects (width, height, size, x, y. All game specific) and check which objects are hit by the vector.
Then pick the one closest to the screen. (Note that the gui, crosshair, windshield, foliage, etc... are objects as well so you may need to ignore those)

In short: It's probably easier if you can find a function inside the game that you can call instead