What causes missing contact shadows making objects float in Unreal?

Standard shadow maps are too coarse to capture the tiny contact shadow right under an object, so without a screen-space contact shadow the gap reads as the object floating.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Missing Contact Shadows Making Objects Look Like They Float in Unreal

Quick answer: Enable Contact Shadows on the light with a small length, or enable per-mesh Inset/Distance Field shadows, so the fine grounding shadow under objects is rendered.

Objects look glued to nothing when the tiny shadow where they touch the ground is missing. Unreal's Contact Shadows feature adds that fine screen-space shadow and grounds them.

How to fix it

1. Enable contact shadows on the light

On the directional or local light, set a small Contact Shadow Length (e.g. 0.05-0.1). This adds a screen-space trace that fills in the fine shadow shadow-maps miss.

2. Tune the length per scene scale

Too long a contact shadow produces dark halos; too short does nothing. Adjust the length to your world scale so small props are grounded without artifacts.

3. Consider distance field shadows

Enable Distance Field Shadows / mesh distance fields so high-detail contact and ambient occlusion under objects is computed independently of shadow-map resolution.

4. Verify shadow casting is on

Confirm the object actually casts shadows (Cast Shadow enabled) and is not marked movable-without-shadow; contact shadows still require the mesh to be a shadow caster.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unreal Engine error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

The errors you never hear about are the ones quietly costing you players. Visibility turns them into a worklist.