9.5.2

324 • CHAPTER 7
OBJECTS MENU • LIGHTING • 325
Memory Requirement (overview)
 Hard shadows and area shadows need memory-intensive raytracing
calculations.
 As more objects are added to a reection/refraction dependent scene, extra
memory will be required.
 A soft-shadowed visible light needs a shadow map of at least (Resolution X *
Resolution Y / 250) KB.
 Omni lights require six times as much memory for their shadow maps.
 When used with transparent textures (light maps), up to 20 times more
memory may be needed.
Render Time (overview)
 Soft shadows are calculated far more quickly than hard shadows, hard
shadows being much faster to calculate than area shadows.
 Making a light visible in a rendered scene adds a negligible amount to
its render time. Using a volumetric light increases render time, sometimes
substantially, according to the Sample Distance.
 Noise adds to render time, with hard and soft turbulence requiring more
calculations than basic noise, while wavy turbulence roughly doubles rendering
time over that of basic noise.
 Using a high sample radius will increase the render time of soft shadows.
 Tube lights and area lights also add to render time, although not to the same
extent as the processor-intensive volumetric light.
Types of light
This section describes the types of light available on the General page.
Omni Spot (round/square). Spot (round/square).