Exercise 5: A flame from a flipbook

Purpose. To make each particle show a moving picture in place of a plain shape.

The flame in Exercise 4 was a ball that changed size and colour. A drawn flame has detail no ball can show. The picture comes from a flipbook: a series of images shown one after another, like the pages of a flick book. Each particle becomes a flat card that carries the flipbook and turns to face the camera.

Before starting

• The workspace holds one new Part with Size 4, 4, 0.2 and Transparency 1. Set both in Studio’s own Properties window. The Part is the card. It is invisible, and only the picture on it will show.
• The plugin has an internet connection. The built-in library is downloaded when the plugin starts.

Procedure

Steps 1, 9, 11 and 12 repeat earlier exercises.

Step	Control	Action	Result
1	The Part	Select, then press Transform	The HUD and the Properties panel open.
2	≡ ▸ Inventory	Press	The Inventory panel opens.
3	Inventory ▸ sidebar ▸ Inventory ▸ MeshFlipbooks	Click	The grid fills with flipbooks. Each thumbnail plays its frames and is labelled with a name and a frame count.
4	Inventory ▸ a thumbnail	Click	The Details panel opens beside the Inventory and plays the flipbook.
5	Details ▸ Insert	Press	The button reads Inserted! for a moment.
6	Properties ▸ Emission ▸ Enabled	Switch on	Ten cards a second appear at the Part. Each shows the flipbook once, from first frame to last, over its one second of life. All face the same way.
7	Properties ▸ Spawn	Expand	The Spawn rows show.
8	Properties ▸ Spawn ▸ Orientation	Set to FacingCamera	Every card turns its picture toward the camera and keeps it there as the camera moves.
9	Properties ▸ Motion ▸ Speed	Enter 3	The cards rise.
10	Properties ▸ Decals	Expand	One layer is listed, named after the flipbook.
11	Properties ▸ Decals ▸ the layer ▸ Transparency ▸ ⋯	Press, drag the right-hand keypoint up to 1, press Apply	Each picture fades out as it rises.
12	Properties ▸ Emission ▸ Enabled	Switch off	The flame stops.

NOTE

Keep the emitter selected while working in the Inventory. Clicking inside the plugin’s panels does not change the selection. Insert writes to whatever is selected, and reads Inserted! even when nothing suitable is.

NOTE

If the grid of flipbooks reads No items, the library did not download. Open Inventory ▸ Textures. If the grid there reads Failed to load, press Retry, then return to the flipbooks. If Studio asks whether the plugin may make web requests, allow it.

What the steps did

Insert added a Decal to the particle’s template, on its front face, and filled a folder of frames for it inside MeshFlipbooks. The Decal is a layer. A particle can carry several layers, each with its own picture, and each is listed under Decals with its own Transparency, Color and Brightness.

In this exercise the Part itself is invisible and the layer is what shows. The Transparency graph in the Appearance section belongs to the Part. The Transparency graph under Decals belongs to the picture. Step 11 used the second one.

Orientation turns each particle every frame. FacingCamera points the particle’s front face at the camera, as long as the emitter Part itself is not rotated. The Decal sits on the front face, so the picture is seen flat on.

The Flipbook section sets how the frames are played. It starts at Mode OneShot: the whole flipbook is spread once across the particle’s life, whatever the Lifetime. A particle that lives two seconds plays the same frames at half the speed.

Mode	How the frames are played
OneShot	Once, spread across the particle’s life. Framerate is not used.
Loop	At the Framerate, starting again from the first frame after the last.
PingPong	At the Framerate, forward and then backward.
None	Not played.

If the result differs

Symptom	Cause	Action
Insert reads Inserted! but no picture appears	The emitter was not selected.	Select the emitter and press Insert again.
A new Folder of Decals appears in the workspace	Nothing that takes a flipbook was selected, so the frames were placed in a Folder.	Delete the Folder. Select the emitter and press Insert again.
The picture shows only from one side	A Decal is drawn on one face of the card.	Set Orientation as in step 8.
A grey or coloured slab shows behind the picture	The Part’s Transparency was not 1 before Transform.	Enter 1 in Appearance ▸ Transparency.
The grid reads No items	The library did not download.	Open Inventory ▸ Textures and press Retry there. Allow web requests for the plugin if Studio asks.

Variations

Change	Result
Flipbook ▸ Mode Loop, then Framerate 24	The frames run at 24 a second and start again after the last, however long the particle lives.
Flipbook ▸ StartRandom on	Each particle starts on a frame of its own, so no two cards match.
Insert a second flipbook	A second layer is added on top of the first, with its own rows under Decals.
Decals ▸ the layer ▸ Color	Tints the picture. Drawn as a graph, the tint changes over the particle’s life.
Spawn ▸ Orientation FacingCameraWorldUp	The cards turn toward the camera but stay upright. They never lean back when seen from above.
Appearance ▸ Size, a graph from 4 to 7	The card, and the picture on it, grows as it rises.

Log

New in this exercise	The Inventory and Insert. Orientation. The Decals list. Flipbook Mode.
Done before	Transform (Exercises 1 and 4). Enabled (Exercises 1, 2 and 4). Speed (Exercises 1 and 4). A Transparency graph (Exercise 4).
Carried forward	Keep this emitter. Exercise 10 uses it again.