To stop climbing up just release the jump button. To start climbing up vines hold the grab button when in front of a vine and hold the jump button to start climbing up. In this case turn into the direction you want to move to start ceiling climbing. If wall climbing is also possible when pressing the grab button, wall climbing will start instead. To stop ceiling climbing simply release the grab button. To start climbing along ceilings hold the grab button when below, but not too far below, the climbable ceiling.

Currently only the steel fence block and the closed trap door block support ceiling climbing.

Smart Moving Mod allows climbing along ceilings as long as the ceiling block supports it. If you are beyond a certain falling speed when grabbing, damage will be done to you. If you are still falling slow enough, free climbing will start. To grab an edge while falling down along a wall, rotate towards the edge in the wall and press the grab button. To climb down click and hold the grab button without moving forward toward the edge. When enabled by configuration or by default you can climb everywhere you find at least a block sized horizontal edge. Smart Moving Mod implements an optional mode of free climbing behaviour.

Smart moving mod controls