Sunday 1 February 2015

How To Use Live Action Reference For Animation

Horse in Motion by Edward Muybridge
How can animators use live action reference to create believable animation?

Back in the old 2D days of hand-drawn animation, rotoscoping (as it was called) was a legitimate, if much debated, method of achieving a realistic look and feel to your animation.

Today, the technology has changed, but 3D animators can also benefit from using live action to help inform their animation, and this is especially the case when doing complex animal or creature animation. So how, in practice, does a MAYA animator use live action reference to get a great result? Below are some techniques for making it work.

Import Live Action Reference into Animation


YouTube: a great source of reference for animation
What are we trying to do?
Our goal is to find a useful bit of live action reference (say, an animal action) from a website such as YouTube, download it, import into Maya, and use it for animation reference. We want to create beautiful, believable animation based on the reference.

Find reference

Dog leap animation by Giuseppe Candido
Let's begin by selecting and downloading an appropriate video from YouTube. It could be a person jumping, a horse whinnying, a dog sniffing the ground - whatever it is you are trying to animate.

Avoid Slow Motion
Try to avoid slow-motion animation. Your animation will be most likely be in real time. If you download slo-motion, you will have to re-time it, which is a pain.

Stable Footage Please
Stabilise Footage in Premiere Pro.
Pick some footage that has been filmed on a tripod, so the camera isn't jumping around.  If you choose hand-filmed footage, or if the camera is moving, you will likely have to spend time in Premiere or AfterEffects stabilising the shot. To see how to do this, follow this link.

Find a Maya Rig That Works
You must have a functioning animation rig capable of achieving whatever it is that the human or animal in the live action reference is doing.

Download the video
Use www.keepvid.com (or any website that can be used to download footage from, say, YouTube) to download the video. (Note that YouTube will not let you download their videos directly - so you need to go to a third party website to do this).

Quick Time Pro 
Edit the video
Now you need to edit the video to the right length. Trim it down to size in suitable software, such as Premiere Pro, or Final Cut Pro, or Quick Time Pro (on a Mac), until you have edited it down to just the bit that you want.

If you have After Effects on your computer, you can use the auto-stabilize feature to stabilise the camera, which will save you time and effort in Maya.

Export the video
Once you are done, export the movie file either as a .mov or .avi file, and import the finished result into Maya.  If you are in Premiere, export as a QuickTime file, which produces a .mov. Maya likes .movs, mostly.

Maya
Open Maya, create a new project, name it, and set to your new project in the usual way.

Import a movie file
To import the movie file, follow these steps:
  1. Copy the video as a .mov (not an mp4) into your Movies folder in your Maya project folder.
  2. Start your timeline at frame 1 (not frame 101) 
  3. In the Maya viewport, go to panels/orthographic/side
  4. Now go to View/image plane/Import movie. The movie file should be directly imported into Maya. Under the show menu turn on image planes so that the image plane is visible in your viewport. Press 6 on your keyboard so you are in texture mode.
  5. In your perspective view, or your camera view, you will also need to turn on image planes under the show menu so that the image plane is visible.
  6. Import your character rig into the shot, and you are ready to animate.  Start off by matching your animation closely to the reference footage. 
  7. Once you have something working reasonably well, you can start to adjust the timing and the spacing to create a believable performance.  The closer you stick to the reference, the more accurate your animation is likely to be. But you may have to change quite a bit to create the performance that you want.

Why doesn't it work?
If your movie isn't showing up, it could be a codec problem with the video. Try going back to Premiere (or whatever editing software you are using) and try exporting your video as a different movie file type. Try mp4, mov and avi files - one of these should work.

You can also try working in a different version of Maya, say Maya 2015 instead of Maya 2016. Sometimes this will solve the problem.

If your image is showing up, but there is no animation - just a still image - make sure the start time of your animation is the same as the start time of the movie file. You can also adjust the offset of the image plane in the Offset channel. Try entering a negative number to make it work.

If this method still doesn't work for you, try Method B below:


Work method B - Image Sequence on an Image Plane
Create/Free Image Plane
Import an Image Sequence

  1. As above, find a YouTube video clip you like. Then use www.keepvid.com to download the video. Import the video into AfterEffects, Premiere, or maybe Quick Time Pro, and cut it down to size, as above.
  2. Now, instead of exporting a movie file, export the individual frames as tiffs jpegs or png files (Tiffs will likely be very large files). NOTE: Maya will not accept underscores, spaces, or brackets in the file names - you will have to delete these. So, export your image files as ONEWORD with no underscores or spaces.
  3. Put the png files in your Images Folder in your Maya directory
  4. In Maya, go to Create/Free Image Plane. Cntrl A for Attribute Editor
  5. In your Viewport, make sure Images Planes is turned on
  6. In the Attribute Editor, navigate to your Images folder. Select the first png file
  7. Make sure that Use Image Sequence is turned on. 
  8. The frames should now appear in your Viewport.
  9. If the frames don't appear, use frame offset to move the frames around (say by advancing it 10 frames or so - or whatever you need). Note that if your first frame number is 100, then you will need to offset by 100 for the frame to show up in your timeline, if you are starting at frame 1.
  10. Now you can match the animation frame by frame.

Troubleshooting:
My image looks weird. What can I do?
Select Create UVs from the drop-down menu and click on planar mapping.

To see an example of the use of live action reference to create great animation, see the video below by Animation Apprentice student Henry Fenwick:




To find out more about Animation Apprentice, click here for a link to Frequently Asked Questions. To sign up for our next classroom at Animation Apprentice, follow this link

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