Page History

$(same_as_output) [nodeName] – The same path that is set in the Output rollout would be used for loading the preview and render caches. When a node name is specified, its output is passed to the current input.
$(simoutput) – A synonym for $(same_as_output).
$(dir) – The scene directory.
$(data_dir) – The default directory where cache files are written. By default this is $(dir), meaning that the cache files are written next to the scene file, but it can be overridden with a custom directory from the Phoenix Global Preferences.
$(scene) – The scene file name.
$(handle) – A unique number of the node.
$(nodename) – The name of the node.
$env(<variable_name>) – An environment variable. See Using Environment Variables.

# signs can be used to specify the cache frame number with at least as many digits as the pound signs. If the number of frame digits is less than the number of pound signs, the number is padded with zeroes to the left. For example:

Play Length | inplength – The duration in timeline frames. In Linear mode, when this parameter is larger than 0, the sequence length is limited to its value. In Loop mode this parameter shows the loop length. 

Auto Origin | autoOrigin – When enabled, if there are any loaded cache files, automatically set the Timeline Origin and the Cache Origin to the first frame of the cache sequence, so changing the Play Speed will stretch the sequence relative to this frame.

Timeline Origin | playat – An offset specifying which timeline frame the starting cache will be placed on. You can think of it this way: "Put cache #(Cache Origin) on timeline frame #(Timeline Origin)".

Cache Origin | inpoffset – An offset specifying which cache file from the sequence will be placed on the timeline at frame Timeline Origin. You can think of it this way: "Put cache #(Cache Origin) on timeline frame #(Timeline Origin)".

Loop Overlap | loopjnt – In Loop mode, specifies the number of timeline frames after the loop's end that will be blended with the loop's beginning to make for a smooth transition. Keep in mind that the end transition frames are not in front of the sequence end, but after it. For example if the loop starts at frame 35 and has a Length of 20 and a Loop Overlap of 5, the transition frames will start at frame 55 and will end at frame 59, which means the simulation must be at least 59 frames long. It is recommended that the Loop Overlap value be longer than the average "lifetime" of the simulation elements while involved in highly visible motion. For example, for a waterfall, the Loop Overlap value should be at least the average time it takes for a water droplet to fall the full distance before being absorbed into the water at the bottom. For a campfire, it should be at least the average time for a particle to rise up and disappear/die. Correct setting of this value is especially important for simulations that contain particles.

Interpolation – Simple linear interpolation suitable for slow simulations. This is the fastest method but it does not capture movement well and may produce flickering.
Velocity – Velocity-based interpolation. Produces better results, but works more slowly. Captures well the movement of the fronts of the plumes, but does not work well for smoke moving backwards, and also may produce flickering. It  requires an exported grid velocity channel from the Output rollout.
Precise Tracing - Improved Velocity based interpolation for Fire and Smoke simulations. Captures fire/smoke plume movement very well and can handle very low Play Speeds. Requires an exported grid Velocity channel, as well as Advection Origin channel from the Output rollout.

Load Nearest If Missing | loadnearest  – If there is no cache file at the required frame, the nearest cache is found and loaded. This is useful for a simulation that ends with a sequence of static frames (for example, still liquid or freezing fire) as it prevents the need to render multiple identical frames after movement has stopped.

Flip Up Axis | ifyz – When enabled, flips the Y and Z axis of the cache's transformation. This is useful when the cache was created with a different up axis (for example in Maya).

Example: Timeline Origin

---

Section

Column width 40% UI Text Box type info The following example demonstrates how the Timeline Origin parameter can be used to specify which frame on the timeline is treated as the first frame when reading the Input Path cache files. The files go from simulationFrame_000 to simulationFrame_030. When the Timeline Origin is set to 10, they are read as if they were saved as simulationFrame_010 to simulationFrame_040. Column width 60%

Example: Cache Origin and Play Speed

 

---

Section

Column width 40% UI Text Box type info The following example demonstrates how the Cache Origin and Play Speed can be used to offset and speed up the input cache files. The files go from simulationFrame_000 to simulationFrame_030. When the Timeline Origin is set to 100, they are read as if they were saved as simulationFrame_100 to simulationFrame_130. The Cache Origin is then used to specify which simulation Frame will be placed on Timeline Origin = 100. Because Cache Origin is set to 10, the whole sequence is shifted 10 frames back such that simulationFrame_000 is placed at frame 90. Thus, the sequence now goes from frame 90 to frame 120. The Play Speed is then set to 2.0. Those thirty frames are now reduced to fifteen. The Cache Origin frame is treated as the middle point when shrinking the sequence. Column width 60%

Example: Looping a Simulation

 

---

Section

Column width 40% UI Text Box type info The following example demonstrates how the Input rollout parameters can be used to loop a simulation. The Timeline Origin parameter is set to 0 - this will be the first frame of the timeline which the Input Path files read into the scene by the Simulator will be placed on. The Cache Origin is set to 10 so simulationFrame_010 will be read and placed at Timeline Origin = 0. The Play Length is set to 15 so the sequence now repeats itself every 15 frames when played back (those are actually simulationFrame_010 to simulationFrame_025). Finally, the Loop Overlap parameter is set to 5 to provide a few extra frames for blending the start and end of the loop together in a smooth transition. Column width 60%