Visual Effects Visual Effects MCQ 2

Question 1

Which compositing operation multiplies the alpha channel of one layer with the RGB values of another to achieve transparency?

Accepted Answer

In

Answer

The 'In' Porter-Duff compositing operation multiplies the source by the destination's alpha, keeping only the overlapping region.

Question 2

In VFX, what is 'pre-multiplication' (premult) used for when working with images that have an alpha channel?

Accepted Answer

Multiplying RGB values by the alpha before compositing to avoid fringing artifacts

Answer

Pre-multiplication bakes the alpha into the RGB channels so compositing operations produce clean edges without color fringing.

Question 3

What does the term 'holdout matte' refer to in visual effects compositing?

Accepted Answer

A matte that protects a foreground element from being covered by a VFX layer placed behind it

Answer

A holdout matte cuts a hole in a VFX element so foreground objects that pass in front of it remain visible.

Question 4

Which rendering technique traces rays from the camera into the scene and simulates how light bounces between surfaces to produce global illumination?

Accepted Answer

Path tracing

Answer

Path tracing stochastically samples light paths from the camera, naturally producing soft shadows, color bleeding, and caustics.

Question 5

In particle simulation, what is the role of an 'emitter'?

Accepted Answer

The source object that spawns particles into the simulation

Answer

An emitter is the origin point or surface from which particles are born into the simulation.

Visual Effects Practice Test