How to Scribble Over a Video in Blender

In this tutorial I'll show you how to draw or scribble over a video in Blender in order to achieve an effect seen in the Justin Bieber 'What do you mean' lyric video. 

The tutorial is divided into five parts: 

1. Introduction to Grease Pencil tool
2. Animating with Grease Pencil
3. Preparing the video
4. Animating over a video, and
5. Rendering

Screencast

How to Scribble Over a Video in Blender

1. Introduction to the Grease Pencil Tool

Step 1

In a new file, Press A on the keyboard to select all objects and then press Del to delete them.

Step 2

To execute Grease Pencil tool, hold D key on the keyboard, and just draw a stroke with left mouse button or your pen tablet, in the 3D viewport. The stroke will finish when you release the mouse button. 

Rotate the view with middle mouse button and you will see that the stroke is in 3D, and can be created from any angle.

Step 3

To see more options for drawing with the Grease Pencil tool, press T and bring out theToolshelf. Click on the Grease Pencil Tab.

Step 4

Here you will see the four basic tools which can be used in drawing.

1. Draw—enables the brush to draw a freehand stroke
   
2. Erase—erases the grease pencil stroke
3. Line—Drag to create straight lines
4. Poly—create polygons by connecting the end points of line strokes

Step 5

You need to hold D key on the keyboard or click the Draw button each time to draw a stroke. You can avoid this by checking theContinuous Drawing option. 

With this option, a sketching session starts, allowing to create multiple strokes. Press Esc or Enter to exit sketching session.

Step 6

At the lower part you will find the Stroke Placement options.

There are several choices for Drawing Settings.

• View—Strokes are locked to the view
• Cursor—Strokes are drawn with position determined by the 3D cursor
• Surface—Strokes are drawn onto the visible surface of a 3D object
  
• Stroke—Strokes are drawn in 3D-space, with their position projected onto existing visible strokes

Step 7

With the mouse in 3D view, Press N to bring up the Properties panel. In the Grease Pencil panel you'll see all other appearance settings.

1. By default a new layer will be automatically added when you start drawing
   
2. Stroke—Sets the line color. Move the Opacity slider to set the transparency of the stroke
   
3. Fill—Sets the color of the interior of the strokes. The opacity slider sets the transparency of the fill color
   
4. Thickness—Sets the thickness of the stroke
   
5. X-Ray—Makes the lines visible when they pass behind other objects in the scene

Step 8

Press the X button to remove the grease pencil object that is the rough scribble you just made.

2. Animating Using Grease Pencil

Step 1

Blender allows you to use the Grease Pencil tool to do tradition 2D animation by drawing frame by frame. Just delete the previous Grease Pencil layer or object if you have any or open a new file. 

Press 1 on the number pad to get into front view. Press 5 to toggle off perspective mode. This will give a neat flat view which will be a good background to draw the animation. 

In the Grease Pencil tab of the tool shelf, turn on Continuous Drawing. This will be useful while sketching, otherwise you might need to hold D again and again to draw. Press the Draw button. You will notice that a new layer for Grease Pencil is created.

Step 2

Press Shift-Right arrow to make sure you are on frame one. I'll be animating a falling circle, you can draw anything you want. This is not an animation tutorial and focuses more on the Grease Pencil tool.

Step 3

Press Right arrow on the keyboard to go to the next frame—frame 2. You can click on the right arrow of the frame counter to go to next frame but since you are in sketching mode you need to press Esc or Enter to exit Continuous Drawing and then click on any other button and then back to Draw button again. 

Therefore it is better to use the keyboard shortcut if you are in sketching mode.

Step 4

In frame 2 you'll see the sketch you made in the first frame. This will go away as soon as you make a new one. Draw the circle slightly at a lower position to animate it falling down.

Step 5

Press Right arrow on the keyboard to go into next frame. Draw the sketch in the frame. Similarly repeat the process to make a shot.

Step 6

Press Esc to exit Continuous Sketching mode. Press Shift-Left arrow to get into first frame or press the Go to First Frame button in the timeline window. 

Press the play button or Alt-A to preview the animation. Press Esc to stop.

The more frames drawn in between, the more fluid and smooth will be the animation.

Step 7

The Grease Pencil tool also has Onion Skinning feature. You can see the previous and next frames. 

In the Properties panel, under Grease Pencil panel, check Onion Skinning to enable it.

You can choose the color for previous and next frames. After selecting Colors, press the Color wheel button to see the changes. You can also set the number of frames to see before or after the current frame.

Step 8

You can add new Layers of drawings in Grease Pencil. Press the + button on the side to add a layer.

Step 9

Layers can help create different objects and sketches as required. Ensure you're on the first frame. Rename the new layer Ground. Set the stroke color to green and draw a line to show the ground. 

Each layer can have its own settings. I want this ground to be stable so there is no need to draw it on every frame.

Press the Play button or Alt-A to see the animation.

3. Preparing the Footage

Step 1

For practice, I downloaded the video fromvidevo.net. I wanted the video to be in greyscale and scribble it over with white. 

If you want to continue with your video as it is, you can skip this part and go directly to Animating Over the Video. To convert the video to gray greyscale, in a new file, click on the Screen Layout button and select Compositing.

Click on the Use Nodes checkbox to enable node editing.

Step 2

Select the Render Layers node with secondary-click and press Del on the keyboard to delete it.

Step 3

With the mouse over the node editor, press Shift-A to bring out Add node menu. Click on Input and then select Movie Clip so that you can import your video file.

Step 4

Click on the Open button of the node and browse for the file.

Step 5

Press Shift-A to bring out the Add node menu. Click on Color and then select Hue Saturation Value. 

You can move a node around by dragging with its titlebar at the top.

Step 6

Connect the nodes as shown in the image. Primary-click and drag the mouse from the Image output socket (yellow dot) of the Movie clip node to the Image input socket (yellow dot) of the Hue Saturation node and then release the mouse button. 

Connect the Hue Saturation node to the Composite node as well.

Step 7

In the Renders properties, in the Dimensions panel, ensure the resolutions are same as the video. 

Check the Frame Rate as well, it should match with the video. 

In the Post Processing panel, check the Compositing option. This will process the render result form the compositing pipeline i.e the node setup.

Press F12 or Render button to render a test frame.

Step 8

I want the white sketches and scribble to stand out on a darker background. So I reduced the contrast and the whiteness in the video. 

To do that, press Shift-A to bring out the Add menu. Click on Color and selectRGB Curves.

Place it between the Hue Saturation node and the Composite node.

Step 9

Tweak the curve so that the whites are reduces. You can also tweak the blacks and reducing the contrast of the whole video.

You can compare the result.

Step 10

In the Render properties and in the Output panel, choose the desired directory and filename for the rendered video. Select MPEG for File Type. 

In the Encoding panel, select MPEG-4 for format.

In the Dimensions Panel, ensure the resolution and frame rate is same as of footage. 

You can also trim the footage from start and end, and input only those frames which you want to use, instead of rendering whole video.

Step 11

Press the Animation button. This will render out the video.

4. Animating Over the Video

Step 1

Now the actual project starts, where you will scribble over the video. 

Press Ctrl-N to create a new file. Hold Shift and then secondary-click on the cube and light to select both. Press Del on the keyboard to delete them.

Step 2

Secondary-click on the camera to select it.

• Press Alt-R to reset its rotation
• Alt-G to reset its location
  
• Press 3 on the numpad to get into sideview
  
• Move the camera away from the 3D cursor because by default, the grease pencil stroke is aligned to the 3D cursor. 
• Select the camera with secondary-click and press G to move or use the arrow widget

Step 3

Press N to bring out the Properties. In the Background Imagespanel,

• Click on Add image.
  
• Select Camera in Axis
  
• Press the Movie Clip button
  
• Uncheck Camera Clip
  
• Increase the opacity of the background video to 1

Step 4

Hold D and start drawing over the video. Press T to bring the Tool shelf for Grease Pencil tool options. 

Check the Continuous Drawing mode. In the Properties panel, change the color of the stroke to white.

Step 5

Press the right arrow button on the keyboard to go to the next frame to draw and animate.

What you draw depends totally up to you and your creativity. At the last frame, use the eraser tool to erase the sketch completely, and it will not appear further in any frame. 

Save the file.

Step 6

You can also see the keyframes in the Dope sheet. 

Split the 3D view and select Dope Sheet in the view type. You can delete, duplicate or move these keyframes.

5. Rendering

Step 1

The sketches cannot be rendered via the Render button in the Render Properties. They can only be rendered via openGL render option. 

Click on the camera button in the 3D view port to render a single frame. You can preview the result and increase or decrease the thickness of the stroke according to your preference.

Step 2

In the Render properties, under the Dimensions panel,

• Set the Resolution and frame rate of the output. The frame rate should be same as the original video but now you can change the resolution. Still, it should be in proportion to original. i.e you can type the resolution of the original video and then decrease the percentage slider if you want a smaller output
  
• Under the Output Panel, choose the desired folder and filename
  
• Select MPEG for file format
  
• In the Encoding Panel, select MPEG-4 for format

Step 3

Finally click on the Clap button in the 3D viewport, to render the video along with scribble over it.

Step 4

To add sound or music, in a new file, select Video Editing for screen layout.

Step 5

Move the mouse over the video sequencer window and press Shift-Left arrow to make sure you are on the first frame. Press Shift-A and click on Movie to add a movie strip.

Set the End frame number according to the video strip length. Click on the End frame counter to input custom frame number.

Step 6

Now again press Shift-Left arrow on keyboard to go to first frame. Press Shift-A again to add a sound clip. I downloaded mine from YouTube's free Audio Library. 

You can select the strips with secondary-click and move them with G key. Both must start on frame one.

Step 7

In the Sync Mode choose AV sync so that we can have a preview with audio and video synchronized.

Press Play button or Alt-A for preview.

You'll see the video and music playing together. If the video does not play smoothly, that means blender is calculating to scale the video to the dimensions  as set in the render options. 

If the resolutions in the Render panel are same of the video strip then the preview will run smoother.

Step 8

Return to Default screen layout.

Step 9

In the Render Properties, under the Dimensions panel, check the resolution and frame rate. 

In the Post Processing Panel, uncheck the Compositing and Check Sequencer. This will process the render through the video editor pipeline.

Step 10

In the Output Panel, select and type in the desired output directory and filename.

• Select MPEG in file type
  
• In the Encoding panel, select MPEG-4 for Format andMP3 for Audio Codec

Step 11

Press the Animation button in the Render panel. This will render the video with the music. Browse for the file and play.