Nodes
HydraRender
HydraRender: renders the 3D scene through a USD Hydra render delegate.
HydraRender: renders the 3D scene through a USD Hydra render delegate. Storm (real-time, in the backend) by default; Karma CPU/XPU when Houdini is installed (runs husk); Cycles (hdCycles) runs in the backend on the standalone engine when the Hydra build is installed. Same inputs as ScanlineRender: bg sets the format, obj/scn, cam. Output: rgba (scene-linear, unclamped), depth (1/Z or Z), optional N. Karma also renders progressively in the Viewer (docs/notes/hydra.md).
| Node | HydraRender |
|---|---|
| Type id | OC_N_hydrarender |
| Menu | 3D › HydraRender |
| Nuke class | none: saved in .nk files as an Oink node |
| Code | opencomp_core/nodes/three_d/hydra_render.py |

Inputs and outputs
| Port | Name | Type |
|---|---|---|
| input 0 | bg | image |
| input 1 | obj/scn | scene |
| input 2 | cam | scene |
| output 0 | Image | image |
Knobs
Panel tab Hydrarender, in panel order.
| Knob | Label | Type | Default | Range / values | Nuke knob | Description |
|---|---|---|---|---|---|---|
delegate | delegate | menu | storm | storm (Storm), karma (Karma CPU), karma_xpu (Karma XPU), cycles (Cycles (hdCycles)) | ||
samples | samples | float | 4 | 1 to 4096 (integer) | Storm: jittered passes averaged; Karma: path-traced samples | |
lighting_enable_mode | lighting | menu | auto | auto, on, off | ||
ambient | ambient | float | 0 | 0 to 1 | ||
output_depth | depth | bool | true | |||
one_over_z | 1/Z depth | bool | true | |||
output_normal | normal (N) | bool | false |
Other knobs (Python, .nk and the assistant; not on the panel)
| Knob | Label | Type | Default | Range / values | Nuke knob | Description |
|---|---|---|---|---|---|---|
gl_color | Viewer Controls Color | float ×3 | 0, 0, 0 | 0 to 1 | ||
postage_stamp_frame | Static Frame | int | 1 | -2147483648 to 2147483647 | ||
lifetimeStart | Lifetime Start | int | 0 | -2147483648 to 2147483647 | ||
lifetimeEnd | Lifetime End | int | 100 | -2147483648 to 2147483647 | ||
useLifetime | Use Lifetime | boolean | false | |||
cached | Cached | boolean | false | |||
bookmark | Bookmark | boolean | false | |||
dope_sheet | Dope Sheet | boolean | false | |||
clone_group | Clone Group | string | ||||
link_source | Link Source | string | ||||
link_overrides | Link Overrides | string | ||||
split_views | Split Views | string |
Nuke equivalent
No Nuke class. In a .nk file this node is written as an Oink node that Nuke will not recognise.