node_inspect
Read-onlyIdempotent
Read Houdini nodes and parameters without modifying them to confirm names, expressions, keyframes, cook results, and validation issues before writing changes.
Instructions
Read one node, or a list of nodes, without changing anything.
Modes: info, parms, schema, changed, names, expression, keyframes, code, cook_chain, explain, material, image, channels, simulation, render_settings, cache, time_dependency, validate, layout, readers.
Use it before you write: to confirm a parameter name, to see whether a
parameter carries an expression, and to read what a node reports after a
cook.
Do not use it to list a network: scene_overview does that.
mode:
"info" — type, inputs, outputs, flags, changed parameters.
"parms" — every parameter, or one parameter when you give
`parm`. The result says whether the value comes
from an expression.
"schema" — the parameter templates: types, ranges, menus.
Read this before you write a menu parameter.
"changed" — only the parameters that a person set: not at the
default, or with an expression or keys. Folders,
labels, buttons and hidden fields are left out, and
a ramp is one entry with its keys.
"names" — the names of the parameters, and nothing else. Read
this first when you do not know the name to write.
"expression" — the expression on `parm`, and its language.
"keyframes" — the keys on `parm`.
"code" — the VEX snippet in a wrangle node.
"cook_chain" — what this node cooks from, upstream.
"explain" — a short account of what the node does here.
"material" — the shader parameters of a material node.
"image" — the COP node: resolution, planes, data type.
"channels" — CHOP channels. `channel`, `start` and `end` read
the samples of one channel.
"simulation" — the DOP network. `object_name` reads one object,
with `field_name` one field of it.
"render_settings" — the parameters of a ROP node.
"cache" — the file cache state of a node.
"time_dependency" — which nodes under this one cook again on every
frame, and what makes each one do it. With
`frames` it times each one and sorts by the time.
"validate" — the names in the parameters of the node that name
nothing: a group, an attribute or a volume that the
input geometry does not hold. That is the failure
that gives a wrong result with no error.
"layout" — for a network: each node that sits above its input,
each pair of nodes where one name covers the
other, wires behind nodes, and the house rules:
node comments, box titles that are sentences or
cut off, a box in a box, a node in a box it is not
part of, a Null OUT_ display node with no Output.
Read it after you add nodes.
"readers" — the parameters that read `parm` through a channel
reference or an expression: what else a write to
it changes.
A solver has hundreds of parameters: give pattern or fields.
Returns JSON. A cook error comes back in the result: an empty geometry with
no error line means the node cooked and made nothing.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| end | No | channels: the last sample frame. | |
| mode | No | One of "info", "parms", "schema", "changed", "names", "expression", "keyframes", "code", "cook_chain", "explain", "material", "image", "channels", "simulation", "render_settings", "cache", "time_dependency", "validate", "layout", "readers". | info |
| parm | No | parms, expression, keyframes, readers: the parameter name. | |
| paths | Yes | One node path, or a list. A list keeps going after a node that fails, and each result names its path. | |
| start | No | channels: the first sample frame. | |
| fields | No | parms, changed: keep only these keys of each parameter, for example ["value", "expression"]. The name is always kept. | |
| frames | No | Read at another frame, or at several: one frame, a list, or {"start": 1, "end": 10, "step": 2}. With time_dependency, time each node. The playbar goes back after. | |
| channel | No | channels: the CHOP channel whose samples to read. | |
| pattern | No | parms, changed: keep the parameters whose name or label holds this text or matches it as a glob. "|" separates alternatives: "time|step|cfl". | |
| field_name | No | simulation: the field of object_name to read. | |
| object_name | No | simulation: the DOP object to read. | |
| has_expression | No | parms: keep only the parameters that carry an expression. | |
| include_all_parms | No | info: list every parameter, not only the ones that changed. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |