This video will show you how to use the motion vector ROP.  Then I will give a brief overview of the material setup in UE4. And then I'll go into some of the details regarding how we calculate a useful vector in texture space.

[UPDATE 10 May 2019] - The ROP now has a raw multiplier value that can be used with the material function code at the bottom of the ROP. Just copy and paste the code into a material function, and input the multiplier as a scalar input.


You can download the latest motion vector ROP from the development branch of our Game Development Toolset on GitHub.

For more info about motion vectors and creating a UE4 material check out Klemen Lozar's awesome tutorial - Frame Blending with Motion Vectors


  • gaoshang1244 2 years, 9 months ago  | 

    NICE tur! How can do in houdini 15?

  • Landerb 2 years, 6 months ago  | 

    Hi mike, I followed this tutorial exactly and all i am getting is the entire frame of each image running up and to the left with no distortion. Any suggestions?

  • mikelyndon-sesi 2 years, 5 months ago  | 

    Does the motion vector texture look correct?
    Have you turned on double apply motion vectors in the material instance?
    Does your number of Columns and Rows value in the material instance match your texture?

  • hdl35301 2 years, 4 months ago  | 

    Thank you for a wonderful tool.
    I have a question.
    If I turn on double apply motion vectors in Material,
    Emission and Alfa flip correctly, and the motion vector continues to flip to the upper left.
    If I turn off Double Apply Motion Vectors in Instance Material,
    The Motion Vector flips correctly, Emission and Alfa continue to flip to the upper left.
    How can I flip Emission and Alfa and motion vector all in the same way?

  • mikelyndon-sesi 2 years, 4 months ago  | 

    Can you check the FlipBook_MotionVectors material function to make sure that the ConstantBiasScale in the Motion Vector Setup section has Bias = -0.5 and Scale = 2.0

  • hdl35301 2 years, 4 months ago  | 

    Thank you for your reply.
    I could solve it as I had you taught me.
    I appreciate you very much.
    Please keep making great tools in the future.

  • Michelleshow 2 years, 1 month ago  | 

    hi , there's an error when I click Render Atlas and I don't know what I can do to fix. I use Houdini 16.5 . I am new to Houdini . Is there any tip?

  • BlackRiverStu 1 year, 11 months ago  | 

    Hey, I`m facing what I believe to be an error on Houdini 16. When I render the atlas, the result frames are all stretched, with a different resolution from what it's said on houdinis interface. For example, on an 8x8 atlas, it says the frames will have the size of 128x128, but its comming as 100x720 for some reason.

    I have tried an animation of 150 frames by using intervals of 15 frames, with no success, and tries picking up only 64 frames, with no frame intervals, and got the same error. The camera is orthographic and I`m using the commercial version of houdini.

    Does anyone have a clue?

  • dmarks 1 year, 11 months ago  | 


    This looks excellent and is exactly what I need. I am having trouble getting the network into Houdini. I've tried both install methods outlined in GitHub, and no matter what I do I cannot get Motion Vector ROP to come up on my node view.

    It is important to note that I'm currently using an Apprentice License, so that I can test these things prior to asking my studio to pull the trigger on a Houdini license. Maybe this is the issue?


    • dmarks 1 year, 11 months ago  | 

      Nevermind.... got it working. Thanks anyways. Great tutorial. Thanks for putting this stuff together!

  • mellacita 1 year, 7 months ago  | 

    For some reason, I'm getting an all-black render. Have stuff loaded in the Export Node and the right camera in the Camera field, but won't render the motion vector at all. I also get an error saying "Error: rendering child" for the atlas.

    What do you think?

    • mellacita 1 year, 7 months ago  | 

      Figured one bit out--was using a non-commercial file and was exceeding the maximum resolution for the atlas. But not sure why the sequence frames are still black.

  • jbaki 1 year, 4 months ago  | 

    I am trying to use this and get a bright yellow outline around my explosion.
    There is also an alpha.
    Are the lights in your scene above important?
    Even with some photoshop to a no blue channel background the image looks nothing like Klemen Lozar's results.

  • ViktorMartynov 1 year, 3 months ago  | 

    I could not repeat Klemen Lozar's material. It gives an error in "SubUV_Funktion". Share a link to the finished material or show how to do it.

  • hflong240 1 year, 1 month ago  | 

    Can I create MotionVector from cloudfx ?

  • mikelyndon-sesi 1 year, 1 month ago  | 

    I don't think so. The motion vectors ROP requires a velocity field and I don't thin the cloud sops generate those fields.

  • allansimonsen 11 months, 4 weeks ago  | 

    Setting the Playbar to 1..100 (and indeed setting global animation options) doesn't seem to have any impact on the Frame Range rendered. This includes going into the Controls and manually setting it to 1-100. Obviously I'd prefer not having an additional 140 frames worth of empty at the end of the simulation :) Any tips to what might have gone wrong? (Houdini 17.5.173).

    • allansimonsen 11 months, 4 weeks ago  | 

      Switched the range to using $FSTART/$FEND instead of RFSTART/RFEND (similar to the rop_pyro_preview node) seems to resolve it. I haven't ducked deeper into the system to see where else that might break things.

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