Visual Effects Visual Effects MCQ 4

Question 1

What is 'rotoscoping' in visual effects?

Accepted Answer

Manually drawing mattes frame-by-frame to isolate a subject from its background

Answer

Rotoscoping is the frame-by-frame manual process of drawing shapes to create an accurate matte for isolating elements.

Question 2

In 3D rigging, what is the difference between FK (Forward Kinematics) and IK (Inverse Kinematics)?

Accepted Answer

FK drives child joints from the parent down; IK calculates parent joint positions from a target position at the end of the chain

Answer

FK rotates joints from root to tip in a chain, while IK positions the end effector and solves the joint angles backward up the chain.

Question 3

What is a 'Z-depth pass' (depth pass) used for in VFX compositing?

Accepted Answer

Storing the distance from the camera for each pixel, used to add depth of field or atmospheric fog in compositing

Answer

A depth pass stores per-pixel distance from the camera, allowing compositors to add depth-of-field blur or fog without re-rendering.

Question 4

Which simulation approach is used by Houdini's FLIP solver to simulate liquids?

Accepted Answer

A hybrid Lagrangian particle and Eulerian grid method

Answer

FLIP (Fluid Implicit Particles) is a hybrid method that transfers velocity between particles and a grid, capturing both fine detail and broad flow.

Question 5

What is 'lens distortion' and why is it important to address in VFX compositing?

Accepted Answer

The warping of straight lines in footage caused by lens optics, which must be matched so CG elements integrate correctly

Answer

Lens distortion bends straight lines in footage, so CG must be rendered with matching distortion (or footage undistorted) for seamless compositing.

Visual Effects Practice Test