Global Settings¶

Scene-wide particle simulation, timeline, cache, compute-device and evaluation controls.

Where to find it¶

3D Viewport > Sidebar > Pro Particles > Global Settings. These scene controls stay in the same place in Lists and Nodes and are shared by both particle authoring modes.

Scene controls¶

These controls affect the whole Pro Particles simulation. Current-frame feedback is automatic: changing a simulation parameter or transforming a relevant source/target refreshes the active frame without a separate Live Update switch.

Global Settings are shared by Lists and Physics Nodes. Switching authoring mode changes the simulation document, but does not create a separate time scale, device selection or interactive cache.

Tuning order¶

1. Keep Global Time Scale at 1 while establishing the physical setup.
2. Start with Substeps at 1 and raise it only when fast motion, collisions or stiffness need finer temporal integration.
3. Leave Catch Up Timeline Jumps enabled when timeline causality matters. Disable it temporarily when the goal is quick inspection of isolated frames.
4. Choose the Compute Device before a long simulation or bake.
5. Use the in-memory cache for iteration and a persistent Output Cache or Alembic export for approved work.

Global Time Scale and Substeps solve different problems. Time Scale changes how much simulation time passes; Substeps divide that time into more solver steps. Slowing time can hide instability but does not replace adequate integration at the final timing.

• Global Time Scale: globally speeds up or slows down particle simulation.
• Substeps: scene-wide minimum number of simulation steps per Blender frame. Raise it for fast motion, demanding collisions, or effects that need tighter integration.
• Catch Up Timeline Jumps: keeps timeline jumps causally correct by simulating skipped particle frames. Disable it when navigating long timelines to evaluate only the requested frame instead of replaying the skipped range.
• Show GPU HUD: shows or hides the compact GPU Preview status overlay. The toggle stays directly accessible in Global Settings whenever GPU Preview is available.
• HUD Settings: a separate section that is collapsed by default. Expand it to adjust the HUD X/Y viewport offset, Scale, and background Opacity. These controls are disabled while Show GPU HUD is off.
• Compute Device: selects the GPU used by particle and Pyro simulation when more than one compatible adapter is available. The refresh button rebuilds the adapter list.
• Framerate Awareness: simulation time follows the Blender scene frame rate, so per-second behavior remains consistent at 24, 30, 60 fps, and other rates.
• Automatic realtime refresh: parameter edits, color-ramp changes, Flow Field edits, and relevant object transforms update the current frame automatically. There is no Live Update toggle.
• Reset: clears the live solver state and in-memory frame cache and returns the simulation to its initial frame. The button remains directly below Global Settings when that section is collapsed.
• Remove Particle System: removes the Pro Particles setup from the scene.

Reset is the appropriate action after changing a setting whose result depends on earlier frames. Automatic current-frame refresh cannot reconstruct an alternate history without replaying from a valid earlier state.

In-Memory Cache¶

The in-memory cache keeps recent Blender Geometry frames for responsive timeline scrubbing. Reset clears it. Use Output Cache when frames must remain available after reopening the project.

• Use In-Memory Cache: keeps recently simulated Blender Geometry frames in RAM for fast scrubbing and timeline playback, including Point Cloud particles, Trails, Instances, Meshers, Dendrites, Cloth, Soft Body, and Strands.
• Memory Cache (MB): maximum RAM budget for these frames. If one frame is larger than the budget, it remains visible but is not kept for later playback.
• GPU Preview and Blender Geometry can be mixed in one setup. Blender Geometry frames are cached; GPU Preview continues to show the live simulation. Revisiting cached Geometry frames can still require catch-up to update GPU Preview.
• Catch-up: with Catch Up Timeline Jumps enabled, timeline catch-up extends the existing valid in-memory Geometry cache instead of replacing earlier frames. It can be stopped with Esc; cancelling a clean catch-up keeps otherwise valid cached frames. If the catch-up is still simulating negative pre-roll frames, Esc discards that partial pre-roll and starts at the scene timeline's first frame. This pre-roll remains cancellable with Use In-Memory Cache disabled. Older frames are removed when needed to stay within Memory Cache (MB).
• GPU Preview timeline jumps: with catch-up enabled, forward and backward jumps that require reconstruction can both be stopped with Esc. GPU Preview refreshes automatically when catch-up finishes, including in combined Pro Particles and Pro Pyro setups. With catch-up disabled, skipped ranges are not replayed.

Choose Memory Cache (MB) from the amount of RAM available to Blender, not GPU VRAM. A larger value retains more Geometry frames but does not increase simulation quality. This budget applies only to Blender Geometry frames.

Evaluation Mode¶

• GPU Preview: the evaluation build has no frame or particle limit while GPU Preview is active. Display changes and preview refreshes remain available after frame 120, including Cloth, Soft Body and Strands.
• Geometry: particle points, generated meshes and curves share a 25,000-vertex/point output budget per frame and are available through frame 120. Excess geometry is cut off with a warning. GPU Preview keeps the complete simulation.
• Output restrictions: Output Cache baking, Alembic, Terrain exports, Flow Field VDB exports and saving Initial States are unavailable in evaluation mode.
• Pro Pyro: Fast GPU Volume has no frame limit in the evaluation build; VDB preview remains limited to 120 frames. VDB export, baking and writing loop files are unavailable.
• Pro Terrain: GPU Preview retains its normal resolution and controls. Heightfield Geometry is cut off at 25,000 vertices, with a warning only when the limit is exceeded.

Use the dedicated Output tab for persistent post-simulation caches and Alembic export.

Switching simulation scenes¶

A Blender file may contain multiple scenes configured for Pro Particles or Pro Pyro, but only one configured scene simulates at a time. Switching to another configured simulation scene resets the live simulation state and in-memory caches before that scene runs. Use persistent Output Caches or Pro Pyro VDB caches when completed frames must survive scene switching.

Troubleshooting¶

• The result changes after a timeline jump: enable Catch Up Timeline Jumps so skipped frames are replayed.
• Catch-up takes too long while exploring: disable it for isolated-frame inspection, but enable it again before judging history-dependent motion.
• A setting change appears to use old history: Reset and replay from the start or from a valid cache state.
• Scrubbing consumes too much RAM: lower Memory Cache (MB). This affects retained Blender Geometry frames, not particle count or solver quality.
• A second configured scene clears the first: only one configured scene can simulate at a time. Bake persistent output before switching scenes when the result must be retained.