# Motion blur, shutterOpen and shutterClose
**URL:** https://forum.aousd.org/t/motion-blur-shutteropen-and-shutterclose/2823
**Category:** Hydra
**Created:** [January 15, 2026, 7:34am UTC](https://forum.aousd.org/t/motion-blur-shutteropen-and-shutterclose/2823 "2026-01-15T07:34:07Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@glevner](https://forum.aousd.org/u/glevner)
#### Post date: [January 15, 2026, 7:34am UTC](https://forum.aousd.org/t/motion-blur-shutteropen-and-shutterclose/2823/1 "2026-01-15T07:34:08Z")
I am developing a generative procedural plugin for Hydra 2, and would like to integrate motion blur support. To determine whether motion blur is required or not, I fetch the primary camera from HdSceneGlobalsSchema, then ask the camera for its shutterOpen and shutterClose data sources.
The problem I am having is that those data sources initially return 0, even if the camera prim contains authored, non-zero values. They continue to return 0 until I set them manually, using usdview’s interpreter window.
Another problem (perhaps related) is that I declare a dependency on the primary camera’s shutterOpen and shutterClose properties in my plugin’s UpdateDependencies() method, and yet changing their values does not trigger an Update().
Any suggestions…?
---
### Author:  [@glevner](https://forum.aousd.org/u/glevner)
#### Post date: [January 15, 2026, 4:48pm UTC](https://forum.aousd.org/t/motion-blur-shutteropen-and-shutterclose/2823/2 "2026-01-15T16:48:21Z")
Well, I found the solution by myself. Changing the shutterOpen and shutterClose attributes from float to double fixes both problems…
---
### Author:  [@glevner](https://forum.aousd.org/u/glevner)
#### Post date: [January 22, 2026, 5:37pm UTC](https://forum.aousd.org/t/motion-blur-shutteropen-and-shutterclose/2823/3 "2026-01-22T17:37:02Z")
I am reopening this issue because, although my procedural plugin sees the shutter values, RenderMan XPU, which I am using to test motion blur, does not see them automatically.
When I run usdview, RenderMan XPU initially ignores the authored values for the camera’s shutter:open and shutter:close properties and says that motion blur is globally disabled. But if I set one of them by hand in usdview’s Python interpreter window, even to the same value, RenderMan XPU then sees the value and performs motion blur correctly.
Any suggestions…?