Step 3 - Add Jumping

Goal

Make the hero jump on Space, but only when grounded, and play a sound. This adds your first conditional branch.

Open this step in the editor: #LI45XB (scene P41T6E#2).

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Run this step:

Babylon Bros - Jump

Blocks Used

• KeyDownEvent (Space)
• GetLinearVelocity, ExtractVector3, Abs, LessThan (ground check)
• Branch (Control Flow)
• ApplyImpulse (Physics)
• PlaySound (Audio)

Step By Step

1. Listen For Space

Add KeyDownEvent configured for Space. Label it "On Space".

2. Check Grounded

Read the hero velocity with GetLinearVelocity, ExtractVector3 to get y, take Abs, then LessThan a small threshold. A near-zero vertical speed approximates "on the ground". Feed the result into a Branch ("Can jump?").

3. Jump And Play Sound

On the true path, add ApplyImpulse on the hero body with an upward vector, then PlaySound selecting the jump sound. Use Sequence if you want the impulse and sound to fire together cleanly.

Editor Features To Use

• Set a breakpoint (F9) on the Branch and run: you can pause and confirm the ground check value before the jump fires.
• Use Debug Mode to confirm only the true path lights up when grounded.

Test And Save

Run, then jump with Space while moving. Save the graph; it should match #LI45XB. Continue with Step 4 - Collect Coins.

Further reading