1-Which type of light would be best to replicate a bare light bulb?
A point light best replicates the effect of a bare light bulb. Point lights emit rays of light in all directions and do not offer a cone and cone feathering option which could simulate a light with a shade.
2- How do lights affect 2D and 3D objects differently?
2D layers are unaffected by lights in after effects. 3D layers are affected by lights. The default lighting in after effects affects both types of layers the exact same way. Using default lighting creates a 100% color value from the layer.
3- What is Ambient Light?
An ambient light is similar to a fill light. It provides even illumination regardless of position in the composition.
4- How is an Ambient Light different from a Source Light?
The effects of ambient lighting are that it is not affected by the location and relative size of the light. The layer will receive the same light effect across the surface no matter what which is different from a source light that has an origin point. The origin point determines the relative brightness and effects it has on the layers.
5- What is a Parallel Light, and why would one use it?
A parallel light is a directional light that casts rays in only one direction. It is similar to the sun in the way it looks like the light source is extremely far away thus creating a more even illumination across the surface. You would use a parallel light for more even illumination but while still wanting the angle of the light to affect the layers.
6- Describes what happens to the illumination of an object as it moves away from a light.
It depends on the type of light being used but assuming that it is a spot light, the falloff of the light will gradually affect the brightness of the layers affected.
7- What happens to a layer as it rotates away from the light source.
It depends on the type of light but with most lights the angle of the rays and the falloff of the light will change the brightness of the affected layers. If its moving further away it will get darker and if the layer faces the opposite direction then the back is lit up while the front is in darkness.
8- Describe a light's Cone Angle?
The cone angle of a light is the angle at which there are no rays emitting from the light source. It is similar to a shade blocking the light.
9- How do I move the light without moving the POI?
If you use the rotation tool the point of interest stays in place.
10- How do I move BOTH the light AND POI at the same time?
You can change the auto-orient settings to technically make it a one node light where the POI moves with the light or you can scrub the values in the timeline.
11- Which type of light is the ultimate 'FILL' light?
An ambient light is the ultimate fill light because of the flat illumination it casts.
12- What does the term 'Diffuse' mean?
The term diffuse is the way the light affects the layer. The falloff in the diffuse will match the falloff of the light.
13- What does the term 'Specular' mean?
Specular is the shininess of the layer and relates to the highlights. It has a sharper falloff than the light source.
14- Can a precomp layer cast shadows?
A precomp layer can cast shadows if it falls within the 5 rules and it must have collapse transformations on.
15- What are the 5 requirements that must be met for shadows to work?
1)A nonambient light must be aimed so that it illuminates both the layer you want to cast a shadow and the one you want to receive.
2)the light must have cast shadows enabled.
3)The layer that will cast the shadow needs to have the option set to on or only.
4)the layer receiving the shadow must have the receive shadows option on.
5)there must be space between the layers casting and receiving shadow.
16- As objects get closer to the layer receiving it's shadow, does the shadow get sharper or more diffused?
The shadow will get sharper.
17- If a layer's 'Light Transmission' is set for 100%, how does that affect the layer?
It mixes in colors from the layers themselves and at 100% will result in the back becoming lit as if it were partially transparent.
18- A 'GOBO' is like a stencil placed in front of a light. Does the layer have to have an alpha, or can the luminosity of the image work?
The layer has to have an alpha but one way to work around that with a 3 channel image is to make the layer a luma matte and use that as a gobo.
19- Adding lights really slows down the render of a scene, what are 3 things that you can do to speed up visual feedback?
You can turn off realtime rendering, turn on draft 3D which turns off shadows, lights and DOF or you can adjust their shadow map sizes to a lower resolution one which can increase speed.20- Can I adjust the brightness intensity of a light below the value of 0? What happens if I do?
You can adjust the intensity below zero. It will cause the layer to lose illumination.
No comments:
Post a Comment