Page tree

Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

LPE EventsDescriptionExample
C
Camera 

All LPEs must contain a camera event.

<type event 'group'>
Scattering event specified by scattering type, scattering event, or lpe groupC<.[DS]C<RD'floor'>[LO] matches all light paths diffuse reflections from the floor lpe group
<L.'group'>
Light, i.e. analytic and geometric lightsC[DS].*<L.'key'> matches all light paths from the key light group
O
Emissive object, i.e. camera visible lights and material glowC[DS].*O matches all emissive object light paths
Wildcard  
.
A period will match any relevant scattering type or event<.D> where the period represents R or T

C.L which is the same as C<..>L or C<[RT][DS]>L

Scattering Types  
R
ReflectionCR[LO] which is the same as C<R.>[DSLO]> or C<R[DS]*>[LO] matches all reflected light pathsdirect reflection
T
Transmission or refractionCT[LO] which is the same as C<T.>[DSLO]> or C<T[DS]*>[LO] matches all transmitted light paths direct transmission
Scattering Events  
D
Diffuse lobes (D1 to , D2, D3, D4)CD[DS]*[LO] which is the same as C<.D>[LO] or C<[RT]D>[LO] matches all direct diffuse light paths.
S
Specular/Glossy lobes (S1 to , S2, S3, S4, S5, S6, S7, S8)CS[DS]*LO] which is the same as C<.S>[LO] or C<[RT]S>[LO] matches all specular light paths direct specular
User Event  

U

User lobes

used

to output material properties, not light transport (U1 to U12)

Note: User events must be explicit and will not match wildcards

CU2L matches the camera visible user2 lobe, typically albedo

Grouping  
( )Parentheses allow grouping of a sequence of LPE eventsCDSL, C(DS)L, and CD(SL) are all functionally the sameequivalent
Alternatives  
|A vertical bar separates alternativesCD|(SD)L matches direct diffuse or specular-diffuse light paths CDL or CSDL
[ ]Square brackets that match any one of the enclosed eventsC[D2D3S2 S3 S4]L matches direct diffuse2 or diffuse3 light paths CS2L, CS3L, or CS4L
[^ ]
Square brackets that match any one event not contained within the bracketsC[^D2D3]L matches all light paths besides diffuse2 and diffuse3 (including specular and user)
Qualifiers  
*
An asterisk will match the preceding event zero or more timesC[DS].*[LO] matches all light paths, including emissive
+
A plus sign will match the preceding event one or more timesC[DS].+[LO] matches direct and indirect light paths, but not emissive
?A question mark will match the preceding event zero or one timesC.?[LO] matches direct and emissive light paths
{n}
Curly brackets that match the preceding event exactly n timesC<T[DS]>CT{2}[LO] matches double transmission light paths
{min,}
Curly brackets that match the preceding event min or more timesC[DS].{2,}[LO] matches all indirect light paths
{min,max}
Curly brackets that match the preceding event at least min but not more than max timesC[DS].{0,12}[LO] matches direct and emissive all light paths with up to one bounce of indirect

In RIB

To specify an LPE in RIB, reference a DisplayChannel in the Display. This is the most basic way to view what's being output.

...