Gotchas

Symptoms that arrive without an error attached, and the fix for each.

Frozen simulation

A particle or cloth sim sits still.

A simulation steps while time is playing. Paused, it holds the current frame, and stepping forward a single frame does not advance it. Scrubbing backward resets and re-simulates from the start of the range, and jumping forward catches up by up to four frames per cook, so a long jump lands short of where the sim would have been.

Press play, and let it run from the start so the sim builds up.

The cook badge does not help here. Setting a node to Auto Cook makes it recook every frame, but a simulation on Auto Cook re-runs pinned to its current state rather than stepping. Advancing a sim is what play does. See Cook policy.

Field with nothing to see

A noise or distance field shows nothing, or a node downstream reports that it wanted an image.

A field is a formula, and only some kinds draw on their own. Colour fields and record fields appear in the viewport unwired. A scalar field appears only if it has a closed form and its show_slice toggle is on. Vector fields and morph fields never appear.

Feed the field into something that needs an image: a display, a paint effect, or an export. See Fields and Rasters (images).

Node produces nothing

A node is wired up and looks correct, and the viewport is empty.

Three causes. The node is Bypassed, so it passes its input straight through and a generator emits nothing. Its result is consumed by something downstream, so it is not drawn on its own. Or nothing downstream is looking at it: only what is being displayed cooks, and a node feeding a dead end never runs.

Check the bypass state first. Then make sure the result reaches the viewport, an open panel, or a pinned panel, wiring a dead branch through to somewhere visible. See The graph & cooking.

The consumed case is the one that looks most like a bug, and it has a control. Making the wire sets that node's opacity to zero for you, in the inspector slider and in the Layer Manager's opacity bar both, which is why it stops drawing. Drag it back up to 1 and the node draws again next to whatever consumes it. Pulling the wire out puts it back to 1 on its own.

Setting opacity to zero by hand is a hide, not a fade. The node stays a real object in the scene and every capture still sees it at full strength; only the live viewport pass leaves it out. That is what lets you hide a Rasterize node's 3D source without blanking the card it feeds.

Mesh nodes ignore points

Points are scattered, then a node that builds or modifies a surface leaves them alone.

Loose points are positions in space. They carry no surface, no faces, and no edges, so a node that operates on a mesh has nothing to hold.

Give the points a surface first. The Mesh node builds a surface from them, and it takes a Gaussian splat scene the same way, decoding it to points and then skinning those. The Iterator node copies geometry onto them, one copy per point: the geometry goes into source, the points go into target, and operation decides whether each slot gets a fresh copy (Replicate) or the source's existing elements are simply re-placed (Transform Only). See Points and Geometry (meshes).

Image softens when scaled up

A logo or photo is crisp small and blurry once enlarged.

An image holds a fixed number of pixels. Stretch it past the size it was captured at and the in-between pixels are invented, because there is no hidden detail to reveal. Shrinking is always clean.

Stay procedural for as long as possible. Shapes, analytic shapes, noise and fields hold sharp at any size. Convert to an image only when pixels are genuinely needed, and bake at the size you will use. See Rasters (images).

For a deliberately blocky look, pixel art included, set the Image node's interpolation to Nearest. Sampling snaps to whole pixels instead of blending. See Rasters (images).

See also