Playfield Motion

Although the previous archetypes are effective as static structures, motion can add a totally new dimension to each – the dimension of time/timing. Complex interaction among moving elements can create a sense of evolution to your levels. Replay value can also be enhanced by introducing a modest number of timed/random events which further increase the strategy required for players to succeed.

Mounted Objects

While not actually a type of motion, mounting objects to one another creates object chains, allowing the constituents to automatically move around together. This can create rigid, mechanical motion, or flexible, organic motion depending upon the type of mounting force used. When combined with physics and/or rotation, you can create some very interesting levels (see Ricochet Recharged and BreakQuest).

Rotation

A single rotating object with a unique collision profile will create very interesting play possibilities (fan blades, gears, etc). When combined with parenting, rotation can create an incredible variety of moving objects. (Note: don’t forget variable rotation speed!)

Scaling

Scaling can be useful when you want to simulate playfield depth or when you want to create shrinking/expanding multi-hit targets. Imagine a Mesh-type level comprised of many scaling objects…

Oscillating

Oscillating motion is where a block or other level object simply ping-pongs back and forth along a vector. Although this type of motion is always a straight line, clever use of many oscillating objects can “suggest” your game has more sophisticated motion (see LEGO Bricktopia). A proper system of oscillating motion will include properties like: initial delay before moving, movement speed, pause at extents, ease in and out, and execute ‘n’ number of oscillations before stopping.

Multi-Coordinate Motion

Providing your level objects with the ability to accept multiple coordinates allows you to send them on a simple path. With a large enough set of coordinates, pause states, timing adjustments, and triggers, this system can produce extremely complex motion.

Path-based Motion

Path based motion is a natural next step if your system supports lists of coordinates for movement (as in the simpler Multi-Coordinate-based Motion above). The difference here is that you will likely want to provide a visual tool for the level designer to draw paths (presumably made up of nodes). The simplest paths would be linear, but once you have the concept of path-following in your system, you could interpolate between nodes along a curve (using B-splines, for instance).

Logic-based Motion

Having level objects react to trigger events is a good initial step on the path to logic-based motion. However, providing playfield objects with the ability to move or adjust motion in reaction to the continuous stream of changes in the game play environment provides more flexibility. This can be as simple as passing the object the current paddle or ball position and providing methods to “avoid” or “home in” on either. Higher levels of complexity would provide multi-object swarming behaviors or perhaps an awareness of the object’s current state to simulate bravery (“home in” while life is strong) or cowardice (“avoid” when life is low).

Scrolling Playfield

The previous examples discussed motion controls for individual objects. Obviously, on a scrolling playfield everything moves at once. Let’s take a look at factors involved in scrolling the Breakout-style playfield.

Vertical Scrolling – blocks (or other level objects) move downwards towards the player; either at timed intervals, due to a switch being hit, or due to game system events (e.g., a lower row of blocks being completely cleared out). Implementing vertical scrolling may result in uncleared blocks hitting the paddle or severely crowding the lower portion of the playfield. That is, if blocks touching the bottom of the screen are not an end-condition for the level. Tip: one way to remedy this is to ensure all the blocks below the new “floor” of the level are destroyed before initiating a scroll. Try putting all the blocks into groups that represent vertical slices of the level and then clear out the appropriate slice before scrolling.

Nervous Brickdown from Arkedo provides several levels with “vertically scrolling shooter” style gameplay. Here the scroll is continuous, and the paddle must dodge obstacles while continuing to rebound the ball.

Horizontal Scrolling – blocks (or other level objects) move left or right across the playfield; either at timed intervals, due to a switch being hit, or due to other game system events (paddle touches left or right extent of screen). Implementing horizontal scrolling risks the ball getting caught between blocks during a scroll and becoming trapped or dragged off the edge of the screen. Tip: try placing your blocks into groups that represent horizontal slices of your level and then clear out the appropriate slice before scrolling. Also try halting playfield action during scrolls to ensure the ball doesn’t get trapped before the scroll is complete. Finally, think about dispensing any important power-ups that might be embedded in level formations before they too scroll off screen.

Scrolling Triggers – as suggested above, many things can trigger a scroll, from a percentage of blocks on the level being eliminated, to a switch being hit, to a certain amount of time passing. Tip: use consistent and obvious rules for initiating scrolls, or you risk the player becoming frustrated when they can’t discern why the playfield keeps changing.

Scrolling Speed – Breakout-style games that implement scrolling tend to display a fairly sedate scrolling speed, giving players time to review level contents or to build anticipation for special items that are scrolling onto the screen. If you want to take a closer look at Breakout-style games that use scrolling, see Funkiball Adventure, LEGO Bricktopia and Nervous Brickdown.