Tracking an Auto-Paint Brush Stroke – Smoke 2013 Ext 1


Welcome to the Smoke Learning Channel. This set of videos focus on tracking. The previous video concentrated on object tracking as well as corner pinning and 4-point tracking. Now let’s look at other places where tracking is available, starting with Auto-Paint. This is used to clean up shots and apply paint strokes to a moving image. If you would like to follow along, please click the link in the YouTube description to download the media. If you are watching the podcast version of this video, then type the link displayed in your internet browser. For this example, we will remove a small distracting symbol on the side of the vehicle. To extract the symbol, we will be using the Paint tool located in the tools tab. First, we’ll make a copy of the segment out to the desktop. Switch from the player view to the thumbnails view. You can be working in any folder you wish, but just check the eye icon in the media library to verify what you are looking at in this view. Now hold SHIFT+OPTION and drag a copy of the segment out to the thumbnails view. Now switch to the TOOLS tab. Under the Effects header, choose the Paint tool. With this cursor, click the clip and than click anywhere on the desktop to enter the paint tool. The first interface you see is normally then Paint menu, which is set to canvas tools. This is absolutely fine for single frame free hand painting. However, if you want to paint strokes over-time, you need to use Auto-Paint. A quick tip regarding your brush settings. The brush settings in canvas menu and auto-paint menu are normally interchangeable. But it has been known for the settings not to stick when switching menus. So my advice to you is not set up your brush in the canvas menu and than switch to auto-paint as the settings could change or reset. So starting off in Auto-Paint, change the Auto-Paint mode to USER. Now let’s set up the brush for this shot. Change the paint mode to CUSTOM and choose Recursive Clone in the pull-down menu. Hold CONTROL+SHIFT and click to set a cloning reference point. Release the keyboard shortcut and click again to set the cloning offset. Now if you are using a pen and tablet than this doesn’t matter. However if you are using a mouse, set your brush pressure to CONSTANT. Now let’s paint. Ensure that Auto-Paint is in RECORD. Start painting out the symbol. You can paint as many times as you like. However you cannot change the cloning reference, as Auto-paint will only use the current offset for the clone. You can only have one clone offset per auto-paint session. When you are done, press the PLAY button to lock in the strokes. Enable the Animation button and turn on the wireframe. Now scrub the time-bar. You can see the stroke paint from red to blue over time. This is how the stroke will paint itself if we used these settings. However we want the same brush stroke for every frame. So decrease the paint over time time-bar to 1. This means the full stroke will be painted every frame, starting from frame 1. Obviously the car is moving but the stroke is not. So we need to track the Stroke. Click the STABILIZER button to enter into the tracking tools. Place the tracker boxes on top of the symbol. Press ANALYZE and the Stabilizer will do the rest. Press RETURN to go back to the Paint Tool. Scrubbing the time-bar, you can see that the stroke is attached to the tracked point. If you need to reposition the stroke on the frame but keep the tracking data, just use the X and Y sliders to move the stroke before processing Auto-Paint. So if you’re ready to go, ensure you are on Frame 1. Press the render button to start painting. One extra bit of information is that you can keep rendering multiple times over the same clip and the stroke will keep getting repainted. So you could reposition the stroke slightly and render again if needed. Last thing to point out here, the STABILIZER only has one tracker box in Auto-Paint because you can only track the position of a stroke and nothing else. Now exit Auto-Paint after the render is complete. Switch to the Timeline Tab. You can now drag and drop the painted clip to a new layer in the sequence or overwrite the old segment. Press OPTION+1 to go to a single viewer. Now move the focus point to the correct layer. You can now play the clip back in the context of your edit. For our next example we move onto masks and look at tracking the mask as an object. Thank you for watching and please subscribe to
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