Wisps User Manual
Animation
- Flipbooks. Point it at an atlas, set the grid, set the frame rate. Frames are always blended into each other, so a short animation doesn’t strobe — you can ship a 16-frame smoke puff and have it read as smooth.
- Seamless loops. Fade the card in at the start of its cycle and out at the end, and a looping effect stops announcing where the loop is.
- No marching in step. Turn on world-position randomisation and every instance starts at a different point in the animation, with no per-instance setup and no scripting.
- Manual control. Scrub the animation by hand from a script when you want the timing to follow gameplay instead of the clock.
- Scrolling textures for effects that don’t need a flipbook at all.
Flow
Flow maps distort the card over time, in two modes:
| Mode | Use it for |
|---|---|
| Distortion | The texture churns and warps continuously. Good for smoke, fog and fire, and it never pops as it cycles. |
| Optical flow | A low-frame-count flipbook is interpolated along real motion, so it moves like a high-frame-rate one without the memory cost of the extra frames. |
Wind
A wind field drifts and warps the card independently of everything else, with its own speed, scale and intensity. Cards in a group sway together instead of each doing its own thing, so a stand of foliage moves like one plant rather than fifty.
Fades
- Soft intersections — smoke meets the floor instead of slicing into it.
- Fade on approach — the card dissolves as the camera walks into it, rather than filling the screen.
- Fade at distance — cards can be culled far away without a visible pop.
- Fade at extreme angles — a billboard gives itself away when you see it edge-on, so past a threshold it fades out.
- Soft edges — a rounded mask so the quad’s corners never show.
Each of these has its own transition control, so you tune where it starts and how sharply it happens.
Facing behaviours
Making a quad face the camera is the easy half. The hard half is what happens when the camera climbs above it. Past a threshold you choose, a card can respond in one of four ways:
| Always face | The classic. The card tracks the camera at every angle. |
| Push | Past the threshold the card starts rotating with the camera, flattening progressively rather than spinning on the spot. Best for grass and ground clutter seen from above. |
| Camera aligned | Past the threshold it lies flat, scaled so the transition doesn’t read as a size change. |
| Stretch | No threshold — the card eases toward flat continuously as you rise. The smoothest option when the camera moves vertically a lot. |
Cards authored around either axis are supported directly. You don’t rotate the mesh to change orientation — which would rotate the texture with it — so a texture painted upright stays upright and unmirrored.
Lighting
Cards take a normal map for real surface detail, and a roundness control that makes a flat quad shade like a volume — a puff of smoke lights from the side like a sphere, not like a poster. Combined with proper alpha handling, cards light and self-shadow plausibly from any direction.
Not included: 3D flipbooks, six-point lighting and aerial-perspective integration. Wisps is a card shader, not a volumetric system.