Tag Archives: Motion blur

[HtoA] [Tip] Speeding up motion blur on VDB volumes

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Merging your velocity vel.x, vel.y, and vel.z grids into a single vector grid using a Vdb Vector Merge node can speed up your renders.

vdb_vector_merge

You can safely ignore the “component grids have different transforms” warning on the VDB Vector Merge.  The x, y, and z components of the velocity have slightly different transforms because they located on the center of the cell faces in each direction; that’s coming from the marker-and-cell (MAC) grid used in the simulation.

If you really want to be precise with the velocities, you need to resample them on the same grid, say the density grid:
unnamed
Hat tips to Saber, Fred

[SItoA] Disabling camera motion blur

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Starting with version 2.8, SItoA no longer supports the Softimage motion blur property. Instead, you use the Arnold Parameters property to control transformation and deformation motion blur.
arnold_parameters_motion_blur

However, you cannot add an Arnold Parameters property to a camera (at least not using the SItoA custom menus, which will tell you that a camera is “is not a valid Object to add Arnold Parameters to”). Here’s a couple of ways to work around that:

  • Create an Arnold Parameters property on a polygon mesh, and then in the Explorer, drag that property to your Camera.
  • Select your camera and run this Python snippet: 
    cam = Application.Selection(0)
cam.AddCustomProperty( "Arnold_Parameters" )