Odd questions

[Slimwaffle]

So I have some odd questions that I feel like might be aimed out the more advanced members of our community. I had some ideas for the project I am working on and just wanted to see if they are do-able.

First Idea;

Is there some kind of parameter for detecting if an entity or location is located in shadow? I was thinking it would be cool to make enemies spawn out of shadows.

Second Idea;

Pretty much the same thing as number 1 but for detecting if light is being cast on an entity. So I could make it that; If player is in direct sunlight then hunger and thirst reduce at a greater rate and apply heatwaves to the screen.

Last Idea;

What is the correct method for getting the terrain height? Is there a way I can set terrain height at location while playing the game? So that the player can hold a button to bring up an overlay to show terrain elevations and then use a second button to raise or lower the terrain. So they can dig raise or flatten ground similar to the way life is feudal does it.

Note; I tried getting the terrain height using code from other forum posts but kept getting error messages and couldn't figure it out. 

[macklebee]

1 and 2: 

3:

 

[Slimwaffle]

Thanks mate much appreciated. I will look these over now.