Rotate a clip about the center of its mask on Fusion

I'm trying to build a Fusion composite that rotates a clip about the center of its circular mask.

So I added an elliptical mask to the Media In, and attached the Media In to a Tranform which will in turn rotate it.

When I set the Pivot of the Tranform to the same as that of the mask and adjust the Tranform's Rotation Angle, the clip starts rotating but soon goes off the screen! On the other hand, if the mask is placed at the exact center of the screen, it works fine.

What did I do wrong here?

Thanks.

I don't think you did anything wrong per se, but are you using the transform only for rotating or also scaling and positioning?

Can you share a composition? (select all your nodes - copy/paste between [code][/code] tags)

I don't think you did anything wrong per se, but are you using the transform only for rotating or also scaling and positioning?

Can you share a composition?

After further investigation, I found that the clip goes off screen only when I manually move the mask in the Node Editor after the first frame of the clip. If I move the mask at the first frame, it works fine. Any idea why? Here's the code. I appreciate your help.

Code: Select all

{
   Tools = ordered() {
      Merge = Merge {
         NameSet = true,
         Inputs = {
            Background = Input {
               SourceOp = "RotateInner",
               Source = "Output",
            },
            PerformDepthMerge = Input { Value = 0, },
         },
         ViewInfo = OperatorInfo { Pos = { 440, -16.5 } },
      },
      RotateInner = Transform {
         NameSet = true,
         Inputs = {
            Pivot = Input {
               Value = { 0.729110529238682, 0.500205616644276 },
               Expression = "Point(InnerMask.Center.X, InnerMask.Center.Y)",
            },
            Size = Input { Value = 1.51, },
            Angle = Input { Expression = "time / comp:GetPrefs().Comp.FrameFormat.Rate * 30", },
            ReferenceSize = Input { Value = 1, },
            Input = Input {
               SourceOp = "MediaIn",
               Source = "Output",
            },
         },
         ViewInfo = OperatorInfo { Pos = { 275, -16.5 } },
      },
      InnerMask = EllipseMask {
         NameSet = true,
         Inputs = {
            Filter = Input { Value = FuID { "Fast Gaussian" }, },
            MaskWidth = Input { Value = 512, },
            MaskHeight = Input { Value = 285, },
            PixelAspect = Input { Value = { 1, 1 }, },
            UseFrameFormatSettings = Input { Value = 1, },
            ClippingMode = Input { Value = FuID { "None" }, },
            Center = Input { Value = { 0.729110529238682, 0.500205616644276 }, },
            Width = Input { Value = 0.234622170873801, },
            Height = Input {
               Value = 0.234622170873801,
               Expression = "InnerMask.Width",
            },
         },
         ViewInfo = OperatorInfo { Pos = { 55, -16.5 } },
      },
      MediaOut = MediaOut {
         CtrlWZoom = false,
         NameSet = true,
         Inputs = {
            Index = Input { Value = "0", },
            Input = Input {
               SourceOp = "Merge",
               Source = "Output",
            },
         },
         ViewInfo = OperatorInfo { Pos = { 605, -16.5 } },
      },
      MediaIn = MediaIn {
         ExtentSet = true,
         NameSet = true,
         CustomData = { MediaProps = {
               MEDIA_FORMAT_TYPE = "PNG",
               MEDIA_HEIGHT = 285,
               MEDIA_LAYER_DESC = {
               },
               MEDIA_MARK_IN = 0,
               MEDIA_MARK_OUT = 119,
               MEDIA_NAME = "test.png",
               MEDIA_NUM_FRAMES = 120,
               MEDIA_NUM_LAYERS = 0,
               MEDIA_PAR = 1,
               MEDIA_PATH = "test.png",
               MEDIA_SRC_FRAME_RATE = 24,
               MEDIA_START_FRAME = 0,
               MEDIA_WIDTH = 512
            }, },
         Inputs = {
            EffectMask = Input {
               SourceOp = "InnerMask",
               Source = "Mask",
            },
            GlobalOut = Input { Value = 119, },
            Layer = Input { Value = "0", },
            ClipTimeEnd = Input { Value = 119, },
            ["Gamut.SLogVersion"] = Input { Value = FuID { "SLog2" }, },
         },
         ViewInfo = OperatorInfo { Pos = { 165, -16.5 } },
      }
   }
}


I can't replicate your problem I'm afraid. Whatever I do with the mask, everything rotates just as I'd expect it to. Can you perhaps make a screengrab/video to show your issue?

I can't replicate your problem I'm afraid. Whatever I do with the mask, everything rotates just as I'd expect it to. Can you perhaps make a screengrab/video to show your issue?

On the Fusion page, move the playhead to frame 100 or later and try moving the mask using the onscreen control. The mask will soon disappear. Thanks again.

I'm using Fusion standalone and it doesn't happen for me, so I can't reproduce your problem.
That's why I was asking for a video to demonstrate, because there doesn't seem to be an actual problem with your setup, which means something else is causing it.

Is your MediaIn long enough? What are you connecting to the merge? (there is nothing connected to it in the code that you posted) etc

I'm using Fusion standalone and it doesn't happen for me, so I can't reproduce your problem.
That's why I was asking for a video to demonstrate, because there doesn't seem to be an actual problem with your setup, which means something else is causing it.

Is your MediaIn long enough? What are you connecting to the merge? (there is nothing connected to it in the code that you posted) etc

If that's the case, I suspect it is a Davinci Resolve bug. In fact, my Davinci Resolve has been crashing at least once per session with no apparent reason. Thank you for your help.

I can't replicate your problem I'm afraid. Whatever I do with the mask, everything rotates just as I'd expect it to. Can you perhaps make a screengrab/video to show your issue?

On the Fusion page, move the playhead to frame 100 or later and try moving the mask using the onscreen control. The mask will soon disappear. Thanks again.

Masks create keyframes when you move them around. If you have moved the pivot point from the center I think it is normal. You should probably animate the pivot point according to your mask animation

Sent from my FIG-LX1 using Tapatalk