PLECK lesson 61 · suggested week 13, day 1
Understand platform coordinates and acceleration
Objective. Distinguish horizontal control, vertical velocity and gravity.
Godot Engine Standard desktop editor 4.7.2-stable, GDScript (Godot 4), Compatibility renderer. Headless Godot 4.7.2.stable.official.ed1daf0bf passed 106 assertions on the supplied scaffolds, including malformed JSON saves. Audio used the Dummy driver and a synthetic WAV, not a speaker. The visual editor, browser export, and signed-in submission were not tested. The desk still does not run a student's own upload.
About 55 minutes. The due date is chosen by a parent.
Gravity, jumps, floor checks and safe geometry
Suggested pace: Recall and predict 5 min; Read instruction and scaffold 12 min; Build or design the assigned artifact 25 min; Run acceptance tests 8 min; Explain and checkpoint 5 min.
Materials: Paper and pencil or a private text document, Local course folder and prior checkpoint, No paid assets or public account required.
Comes after VGC-L060.
Relay Runner is a short delivery platformer. Horizontal input directly selects a sideways velocity, while gravity accelerates the player downward over time. In 2D positive y is down, so a jump begins with negative y velocity. Acceleration changes velocity; velocity changes position through move_and_slide. Do not add gravity directly to position. Draw the expected vertical-velocity signs for rising, peak and falling. Keeping these ideas separate helps diagnose a jump that moves backward or falls upward.
Worked example
A ball thrown upward begins with negative y velocity. Gravity adds a positive amount each physics step, slowing the rise and eventually producing downward motion.
Understand platform coordinates and acceleration — evidence task
- 1. Sketch a jump arc and label y-velocity signs.
- 2. Predict what doubling gravity does if jump speed is unchanged.
Deliverable. Annotated jump diagram and prediction note.
Acceptance checks
- VGC-L061-T1. Rising is negative y velocity and falling is positive.
- VGC-L061-T2. Prediction distinguishes initial jump impulse from continuing acceleration.
Understanding question. What is vertical velocity near the top of a jump?
Submit readable text or photos/scans of each numbered design page. Audio explanation may supplement a diagram or text, not replace requested artifacts.
If this is still shaky. Use C-PLATFORM with one wide floor and no hazards. Verify floor contact before adding platforms. Start with the first assigned task and re-run its acceptance test before adding the remaining feature.
Optional extra. Compare two gravity/jump-speed pairs while keeping horizontal speed fixed. Document one changed parameter, your prediction, and the observed effect; optional, not required for completion.
Turn in a typed answer, a JPEG, PNG, or WebP photo, a PDF scan, or an MP3, WAV, M4A, MP4, or WebM file up to 4 MB. A parent can log paper. One https address is stored as text and is not opened or run. Zip and code files are refused.
- Your first 2D game
Free public tutorial; no account; external asset download is optional, not used by this course.
· Opening this link does not submit the lesson.
This is a preview. A parent assigns the lesson and chooses the due date after the student is enrolled. The answer key is not on this page.