Thursday, January 12, 2006

Visual Effects lesson 101-106

(Blog post, no podcast)

Here is a basic visual effects lesson for those just starting out:

1. Think of a simple concept to do as a test shot.
Do this as a still so you don't have to worry about moving images,interlacing, compressed video, etc.
Select something that is realistic - feasible and believable. (i.e. no pink whales type creatures with feathers floating in the clouds.)

2. Shoot the background with and without a reference. Repeat step 1 if you can not shoot a reference. If you're going to composite a person in the scene shoot it with and without a person. If you're going to create and render a CG model then put in the real object you're duplicating.

3. Shoot or create your additional elements.

4. Composite this image with the background. Adjust until it looks real (without looking at the reference).

5. Compare this result with your reference. Do they match? If not, repeat adjustments (color, matte edges, etc) until it does. You may find you have to go back to the shooting of the FG element or modeling and rendering to get it to work.

6. Try some variations- put the object in the far background if you have an outdoor scene. You'll see how atmospheric perspective comes into play. What matched up front no longer looks real when reduced and placed in the background. Move the image to an area with different lighting. See how that stands out.

There are a number of lessons to be learned here (I'll cover some of these in more detail in future podcasts):

1. You don't need a teacher or VFX supervisor to tell you if you've gotten the objective issues of a shot correct.
With a real reference as both a reference and a goal, keep thinking what's wrong with this picture.
You will have creative and subjective issues in the future but for now you're focused on how to obtain a match.
A good visual effects crew member is able to take the ball and run with it to the point where only creative issues need to be discussed.

2. What you think was real and what was actually real are probably two different things. Bounce light, highlights, shadows and textures are all issues that can be surprising.
What the director wants and what's cinematic are two additional variations. These four things may match or may be wildly different.

3. A reference clip or still is handy to have when shooting or creating your other elements.

4. Do you know your tools and techniques well enough to accomplish this? If not take a look at your problem area and try to learn more about it.

5. Developing your eye takes time and effort. It involves making observations of what happens in real life and what happens in photography. Learn to see.

6. Creating reality has the advantage that you can have a real reference and that you know exactly what it needs to look like.
Creating a pink whale type creatures with feathers floating in the clouds doesn't offer that. It will always be something of a guesstimate on exactly how that would look and it will more likely be a creative decision.
A totally fictional and impossible image is always going to be 'unreal' even with the best rendering and compositing. Your mind knows it can't exist and each person is going to imagine it should be a slightly different way, if it were real. It works because the audience is hopefully willing to suspend disbelief, especially if it's a good story.

Future projects:
Repeat with different scenes. If you created a CG object place it in these new scenes.
Try with multiple objects or people.

Next try with moving footage. If you're an animator try the same thing.
Have a person walk and jump over something. Try to re-create that.

Good luck.

If you're interested in Visual Effects Schools (including online) click here for that posting.

5 comments:

  1. Places to check for visual effects footage:

    Your school/college if you're taking classes.
    VFX software companies. I know we included clips with Commotion and others do as well for tutorials.
    Some of the visual effects books for compositing and specific packages include CD's or data DVD's with material. See some of the books at the Effects Corner store
    http://www.pixelcorps.com/ as I understand it provide some material to their subscribers.

    ReplyDelete
  2. Very useful post. This is something I plan on doing very soon with some 3D models that I'm working on so it's helpful to actually have an outline of how to practice.

    Scott, do you use other compositing applications besides Commotion and if so which ones and why?

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  3. Yes, I use multiple applications. AE and Shake among others. I usedCommotion for the Levis spot and AE for the BMW (probably cover that in another podcast). Bounced around a bit forthe Skittles spot.

    ReplyDelete
  4. nice blog as well as VFX tips !!
    Check CG India for Latest VFX news.......!!
    cgindia.blogspot.com

    ReplyDelete
  5. Scott,
    I got some poster board to test out keying and do
    stills for now.

    1."Think of a simple concept to do as a test shot"

    These are real objects to use:

    Ok Scott I have this small minture light color wood
    table about the height of a number 2 pencil.(So that's
    small)
    And lastly I have this darker color wooded vase that
    has been lathe. And when relate the size to the table
    it huge.

    Now I want to beable to size down the lathe vase and
    place it on top of the small table so they both look
    like they are improportional to one another and appear
    to look natural

    How wood I start this you said 2."Shoot the background
    with and without a reference."

    Scott Squires said"I'd suggest taking one step back.
    Shoot a real table with and without the vase.
    Then shoot your vase against a
    greenscreen/bluescreen.
    Composite that on the image of the table. Try to
    get the composited vase
    and it's shadow to match the reference image of that
    same vase shot on the
    table.

    Once you've mastered that then shoot your miniature
    table. If you can try
    to locate a miniature wooden vase or some object
    similar in texture,color
    and size to what you want your image to be. Shoot
    the miniature table with
    and without this reference.Now shoot your full
    size vase and composite it
    over this.One of the things you may notice is the
    little details such as
    texture of the wood is very different for the
    scales.

    You can post questions in the comment section on the
    website. That way
    others can learn from these exchanges as well.

    Good luck,
    Scott

    ReplyDelete

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