> For the complete documentation index, see [llms.txt](https://shaheerxansari.gitbook.io/hydroportdoc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://shaheerxansari.gitbook.io/hydroportdoc/troubleshooting.md).

# Troubleshooting

## The fluid is missing or invisible

* Check the `.abc` file path still points to an accessible file.
* Confirm that the file contains **one deforming polygon mesh** with samples, not an unsupported multi-mesh or crowd hierarchy.
* Verify **Position Scale** and actor transforms; incorrect units can put geometry out of view or make it unexpectedly tiny/huge.
* Try previewing a frame known to contain geometry.

## The cache looks too large or too small

Select the appropriate Source Preset or use **Custom** and set Position Scale according to the exported file's actual unit convention. Reimport to apply geometry conversion changes.

## Playback is slower than expected

A large cache may require substantial decoding and mesh upload for each newly requested sample. Avoid assuming that random-frame editor scrubbing should be real time. Work with fast storage, use a lighter preview cache if possible, and render final frames in MRQ.

## Import settings appear to do nothing

Import settings are not generally live. Set options first and then import/reimport. In the checked-in source, **Recalculate Smooth Normals** triggers reimport automatically; other values may not until reopening.

## Surface looks faceted

For compatible cloth-like or smoother deforming surfaces, try **Recalculate Smooth Normals**. For fluid caches, the default **Off** preserves the normal handling intended for fluids. Test the resulting shading on your material.

## Motion blur is absent, weak, or excessive

* Ensure velocity data exists in the Alembic export.
* Enable **Import Velocities** *before* importing.
* Verify Velocity Units, Velocity Scale, and Alembic FPS.
* Check Post Process Settings and MRQ temporal-sample setup.

## Ghosting in MRQ

Use **Spatial Sample Count = 1** and try **Shutter Timing = Frame Close**, the developer-reported recommendation for HydroPort fluid renders. Compare a short rendered range first. Frame Close is not a universal cure for all motion artifacts.

## Material renders as default material

The custom renderer uses Unreal's **Geometry Cache vertex factory**. The code checks for material compatibility and can fall back to the default material when required permutations are not available. Check the material's relevant usage flags and shader compilation.

## Still having problems?

When requesting support, provide engine version (5.7/5.8), plugin build/version, source DCC and Alembic export options, FPS, preset/scale settings, a short log excerpt, and a reproduction with a small cache where possible. Do not share confidential production caches publicly.