Troubleshooting

Symptom first, then what causes it.

The window will not open

ImportError: No module named Am_landmark or No module named 'AM_Tools' — Maya cannot see the install. Almost always one of:

• a second, stale AM_Tools definition in another .mod file is hiding it — Maya honours the first it finds and drops the rest silently. Drop the installer again; it lists every definition it can see and offers to switch the extra ones off.
• the tool went into a different AM_Tools from the one Maya is reading. Drop the installer again and look at the band under the Destination field: if it is amber, press Use it and install again. Only one AM_Tools on a machine is ever visible.
• the module was never registered (Register the AM_Tools module with Maya was cleared at install time).
• the folder was installed by hand and its parent is not on PYTHONPATH. It must be called exactly Am_landmark.

See Install.

The installer proposes a folder I do not recognise — it found an AM_Tools there. The band under the path names the tools already inside it; that is the module Maya is set up to read, and it is where this one belongs. Change it only if you mean to move the whole module, and expect the warning.

It opened once and now does nothing — running Am_landmark.load() again closes the previous window and opens a new one, so a window that seems not to appear is usually behind Maya. Turn Settings → Keep the window on top back on, or check your other monitor: the window restores its last position, and a monitor that has since been unplugged would put it off screen. It is clamped back on screen if that happens, but a very unusual layout can still hide it — Reset Preferences clears the stored geometry.

Nothing happens after I edited a file — Maya cached the module. Use the reload button; importlib.reload on the package is not enough.

Assigning does nothing

Nothing selected in the viewport to assign to — exactly what it says. The toolbar read-out tells you what Maya thinks is selected.

I selected the object, not faces — that is fine and is assigned as an object-level assignment. If you wanted only part of it, select faces.

I selected a NURBS surface — landmarks are per face; only polygon meshes have faces.

The face count did not change — you assigned the landmark that was already on those faces. The count is what is wearing it now, not what you just did.

The colours look wrong

Everything renders darker than the swatch — your scene is colour-managed and the shader plug wants linear values. Turn on Settings → Write colours through sRGB to linear. See Colour space.

The colour changes across the surface — the landmark is a lambert or blinn, so it shades with the light. Convert it to surfaceShader (Change Shader Type) and it goes flat, keeping its assignment.

Two landmarks look the same in the viewport — generate the palette with Distinct rather than Hue Wheel at a high count, or press the palette button in the row of actions to re-spread the colours you already have.

The colour I set in the Attribute Editor is not in the list — the list refreshes on scene changes and on F5; press it.

The mirror did nothing

Nothing to mirror: no landmark faces found on the source side — the faces you marked are on the negative side and the direction is Positive to Negative. Flip Direction, or use Swap Sides.

Maya symmetry is off — you are in Topology (Maya Symmetry) mode. Press Enable Maya Symmetry on the page, or switch to Spatial.

It mirrored some faces and not others — run Check Symmetry, then Select Unmatched to see which. Usually the tolerance; sometimes the model. Checking and fixing walks through it.

It mirrored onto the wrong place entirely — the plane is wrong. Check Axis, Space and Plane at; the pin button next to Plane at sets it from the selected mesh's bounding-box centre.

Nothing pairs at all on a mesh I know is symmetric — the mesh is probably not at the origin and you are in Object space with Plane at 0, or in World space with the mesh moved. Try the other space, or set the plane with the pin button.

The mesh is posed — spatial matching cannot work; use Topology (Seam Seed).

Loading a file

The file refers to meshes this scene does not have — the mesh names in the file do not match this scene. Open Rename meshes on load and set a search and replace, a namespace, or strip the file's namespaces. See Loading.

This file has no UV samples — it was saved without them. Either save it again from the original scene with samples on, or load by Face Index or Position.

N samples found no face within X — raise the tolerance, or the meshes are more different than the method can bridge. UV tolerances are in a 0–1 space; position tolerances are in scene units.

headShape (face ids out of range) — the file describes a denser mesh than the one here. The ids that exist were assigned; load by UV or Position instead to get the rest.

no colour set to match against — Colour Set was chosen and the mesh has no vertex colours. Bake first, or pick another method.

Landmarks came back but nothing is assigned — Re-apply face assignments was off, or the file was saved with Include face assignments off.

Shader types

aiStandardSurface is not in the menu — mtoa is not loaded. Load the Arnold plug-in and reopen the menu; only types this Maya can actually create are offered.

Converting lost my roughness — type-specific look-dev values do not travel, because they have no counterpart on the new type. Colour, transparency, the tag, group, notes, id and the whole face assignment do.

Cleanup

Delete Unused removed something I wanted — Ctrl+Z; it is one undo step. It only ever considers landmarks with nothing assigned to them, so the usual cause is a landmark you made and had not assigned yet.

My own materials disappeared — they cannot have been deleted by this tool: cleanup only touches tagged landmarks, and never a default, referenced or locked node. Check the Hypershade and Maya's undo history.

Performance

The list takes a moment on a huge scene — every row counts the faces wearing it. Turn off Settings → Follow the scene automatically and refresh with F5 when you want it.

A big mirror takes a few seconds — face centres are computed for the whole mesh. It is linear in face count, and it is one operation; on a multi-million face mesh, prefer Selected faces only.