How can I lay down an object on a plane? I am creating a scene with different objects scattered around, as if they were laid down on the floor, and I found that one of my objects it not touching the plane (the monkey head in the back).



So I have to move really up close to the object (then at some point the zoom strength slows down, not sure why), spin the scene around so as to be have my view aligned with the plane, then move it little by little.





But it's a Monkey head, so there's the jaw part, and there's the back of the head.
So after I align the jaw, I see that the back of the head isn't laid down on the plane, just the jaw is.



So I rotate, grab the object up on the Z axis... then the jaw isn't touching anymore...

And then I thought "wait, there's got to be a simpler way to do this".
One solution is to use Blender's rigid body physics simulation. Basically, you simulate the object falling and settling on the floor from gravity.

In the Properties > Physics panel, turn on both Collision and Rigid Body for both your floor object and the object you want to lay down.



For the floor object, change the rigid body Type to Passive.



Press AltA to animate the physics simulation. You should see object fall down to the floor and eventually come to rest. Press AltA again to stop the animation. If you want to apply the final position to all frames, select the object and press CtrlA>Visual Transform, then turn off the physics for those objects in the Physics panel.