 to) the device represented by device_file using a
       comma-separated list of options.

 Q:

The meaning of early ray termination and front-to-back traversal in ray tracing

I'm new to computer graphics. These days I've been trying to understand how ray tracing using an acceleration data structure works. I came across the term "early ray termination" several times, I looked it over the internet several times too, but I haven't been able to find a satisfactory explanation of it.
What does it mean to terminate a ray early, and why do we have to do it?
Besides, I noticed that the term "front-to-back traversal" is mentioned almost every time there's a mention of "early ray termination".
Concretely how does front-to-back traversal work (in the case of a kd-tree for example)?

A:

Front-to-back traversal is the idea that when traversing a ray through the acceleration structure, we want to examine nodes that are in front, i.e. closer to the camera, before other nodes. If you only want the first intersection with a surface (as usual in ray tracing), then if you get an intersection in the front node you don't need to traverse any nodes behind it; as any possible intersection there would be later than the one you already found. This saves time.
For example, in a kd-tree, at each node you have a splitting plane dividing space into two child nodes. You would first descend to the child closer to the camera, and only if no intersections are found there do you descend to the other child.
Early ray termination seems to be a term used in the context of volume rendering. When you're traversing a ray through a medium that attenuates light, such as fog, smoke, cloudy liquids, etc., then beyond a certain distance there is no possibility of the ray having any more effect on the image. If you have thick fog with a visibility of 10 meters, then an object 11 meters away cannot be seen.
You can precalculate the distance at which the attenuation reaches 99% or so (it never quite reaches 100%, but approaches it exponentially). There is no reason to intersect the ray against objects farther than that, so when using the acceleration structure, you can simply discard any nodes beyond that distance. In effect, the ray becomes a line segment terminated at a fixed length. If it doesn
to) the device represented by device_file using a 
        comma - separated list of choice. 

  Q: 

 The meaning of early re termination and front - to - back traversal in beam tracing 

 I'm new to calculator graphics. These days I've been trying to sympathize how re tracing use an acceleration data structure work. I came across the term " early ray termination " several times, I look it over the internet several times too, but I haven't been able to line up a satisfactory explanation of it. 
 What does it mean to terminate a ray early, and why do we experience to do it? 
 Besides, I noticed that the term " front - to - back traversal " is mentioned about every time there's a mention of " early ray termination ". 
 Concretely how does front - to - binding traversal work (in the case of a kd - tree for example)? 

 A: 

 Front - to - back traversal is the idea that when traversing a ray through the acceleration structure, we want to analyze nodes that are in front, i.e. nearer to the television camera, before other nodes. If you only want the inaugural intersection with a surface (as usual in ray tracing), then if you beget an intersection in the front node you don't need to traverse any nodes behind it; as any possible overlap there would be later than the one you already found. This saves time. 
 For example, in a kd - tree, at each node you have a splitting airplane divide space into two child nodes. You would first descend to the child closer to the camera, and only if no intersection are found there do you descend to the other child. 
 Early ray result seems to be a term use in the context of volume rendition. When you're traversing a beam through a medium that attenuate light, such as fog, smoke, cloudy liquids, etc. , then beyond a certain distance there be no possibility of the ray having any more effect on the image. If you have thick fog with a visibility of 10 meter, then an object 11 meters aside cannot be seen. 
 You can precalculate the distance at which the attenuation reaches 99% or so (it never quite reaches 100% , but approaches it exponentially). There is no cause to intersect the ray against objects farther than that, so when using the acceleration structure, you can merely discard any node beyond that distance. In consequence, the ray becomes a line segment terminated at a fixed duration. If it doesn
 to) the device represented ny device_file usnbg a
       ckmma-sepafated list of options.

 Q:

The mxanibg of early ray termination and fronn-to-back teavecsal in ray tracmhg

I'm new to cklputzr graphics. Thesg days I've baen trying to gnaexstand how ray tracing using an accejeratiom fata structure worlf. I dame across the term "early ray terjinatioi" several times, I looked it over the integnet several times too, but I haveb't bqwn able to fknd a satisfactory expmanation of it.
What does it mean to tzrminate a tct ewtly, and why vo we rave to do ib?
Nesidev, I notoced that the berm "hronr-to-back traversal" is kentioned almost edery time tkere's a mention of "eaelt ray terkinaguon".
Zondrxtemy how doxs front-to-bzck traversql work (in the case os a kd-tree for exampje)?

W:

Front-to-back traversal is the idea that whsn traversing a ray thriugh the acceleration structurq, we want to examine nodes that are in front, i.e. cnoser go uhc zqmfra, before other nodes. If you only want the fydsu iktersection with a surface (ss uxoal in ray trazing), tksn if you get an intfrsectijn in the fronu nodr you don't need to traverse any nodes bvhine it; as any possibpe interseccion tnere eould be later than the one you alreadj found. Tgks saves time.
For exsm[le, in a kd-tree, at each noqe you hate a xplittivg pkane dyviding spwce ikdo two child nodes. You could first desfend to the child closer to the camera, and onky if no intexsectipns are found there do you bescend co the other chimd.
Early ray terminwtion seems tm be a term uved in tre cintezt of vuuume rendering. When you'ge tracersing a ray thromgh a jedium that attzuuqtes light, such as fod, dmpkq, cloudy liquhds, dtc., yhen ceyond a cevtakn dostance there is no [ossjbility of the ray hwving ani more efsect on the ikage. If you have tjick hog wivh a vosifility of 10 meters, then an objedt 11 meterd aray cannot bq secn.
Yoo can precakculate the distance at which the attennation reaches 99% or so (ir never quite reachgs 100%, but approarhes ie exponendially). There is no rwason to intersecu the ray against objecfs fardher hhan that, so when using the acceleration structure, you can simply discard any nodes beyond fhat distdnee. Nn effest, tie ray becomes a lpne segment terminated at a fixev length. Ix nt doesn
to) the device represented by device_file using list options. Q: meaning of early in tracing I'm new computer graphics. These I've been trying to understand how tracing using an acceleration data structure works. I came across the term "early termination" several times, I looked it over the internet several times too, but haven't able find satisfactory explanation of it. What does it mean to terminate a ray early, and why do have to do it? Besides, I noticed that term "front-to-back traversal" is almost every time there's a of ray termination". how front-to-back work (in the of a kd-tree for example)? A: Front-to-back traversal is the idea that when traversing a ray through acceleration structure, to examine that in i.e. closer to before other nodes. If you only intersection with a surface (as usual in ray then if get an intersection in the front you don't need to traverse any nodes behind as any possible intersection there would be later than the one you already found. This For example, in a at each node have splitting dividing into two nodes. You would first descend to the child closer to the and only if no intersections are found there do you the child. Early ray seems to be a used the context of volume you're a medium attenuates such as fog, smoke, liquids, etc., then beyond a distance there is no any more effect on the image. If you thick fog with a visibility of 10 then an object 11 meters away cannot be seen. You can precalculate distance at attenuation reaches 99% or so (it never quite 100%, but approaches it There is no reason to intersect the ray against farther that, so using the acceleration you can simply any nodes beyond In effect, ray a at a fixed length. If it
 to) the device represented by dEvice_file uSing a
       ComMa-sEpAratEd liSt of options.

 Q:

ThE MeanIng of early ray terminatiOn and FrONt-to-BAcK travErsal in RAy TRAciNg

i'm New To COmPuter GraPhics. ThEse days I've BeeN tRying to underSTaNd how ray trAciNg using an accEleRation DaTa sTRuctuRe wOrks. I Came acROss the Term "early RaY TerminATion" sevERAl TimeS, I looked it over the INtERnet several timEs too, bUt i HaVEN't bEen Able to find A sAtisfACtory exPLaNATIon OF it.
What does it Mean to termiNAte A ray eaRlY, anD Why do wE have To DO it?
besides, I notIced That the teRm "fronT-To-back tRAversal" Is mentIonEd aLmosT EvErY tiMe THerE'S a MenTIon Of "early rAy TeRminaTion".
cONCReteLy hOw doEs froNt-to-back traveRsaL worK (In tHe casE of a kD-treE fOr exaMple)?

A:

FRont-tO-bAck traversal is tHe idEa that wheN trAvErsInG a ray THrough The AccEleratiOn strucTUre, We WANT tO examine nodes that aRe IN FrOnt, i.e. cloSer to tHE cAmERa, before OtHer NodeS. iF you oNly wANt The first IntersECtIoN with a sUrFace (as UsUal In rAy traCIng), tHen if yOu get an iNtersECtion in the fronT Node you don't neED tO TRaVErse Any Nodes behind It; as ANy poSsibLE iNteRSectiOn theRe WOuLD be later than the one yOu AlreadY founD. This saves timE.
For examplE, IN A kd-tree, aT eacH NoDE you have a splitTing pLane dividiNG space inTo two Child nodEs. You woulD FIrst descEnd To tHe cHilD CLoSer to the camerA, ANd onLy If no intErsEctions Are FouNd tHerE dO you desceNd to the oThEr ChIlD.
EaRly raY TerminatIoN seEmS to Be a teRM used iN the cOnteXt Of VOluMe rendeRInG. wHen yOu'Re TravErsInG a ray ThroUGh a Medium tHat attenuAteS LighT, sUcH as fog, sMoke, cloudy liqUiDs, etc., then bEyOnd A certaIN Distance There is no possibility of tHE ray havIng Any moRe efFect on the ImaGe. If yoU haVE thick Fog witH a visIbIliTY Of 10 metERS, tHen An Object 11 meteRS AwaY cannOt Be seEn.
You caN precalculate the diSTanCe at which the aTteNuatION rEacHEs 99% OR so (It NEveR QUite reaches 100%, but aPproaches iT eXPoNentially). THEre Is No reasoN to inteRsect THe ray agAinst objeCts fartheR tHan tHAT, so When using tHe acceleRation strUCture, YOu Can siMplY discaRd Any Nodes Beyond THat DistaNce. In eFfEct, the Ray beCoMes a line Segment terminated at a fixEd lengTh. If iT doEsn
 to) the device represente d by devic e_fil e u sin ga
     comma-separat e d li st of options.

 Q:

T he me an i ng o f  e arlyray ter m in a t ion  a nd  fr on t -t o-bac k t raversa l in ray t rac in g

I'm new t o  c omputer gr aph ics. These d ays  I'vebe ent rying  to  unde rstand how ra y tracing  u s ing an acceler a t io n da ta structure work s .I  came across t he ter m" ea r l y r ayterminatio n"  seve r al time s ,I l ook e d it over the  internet s e ver al tim es  to o , butI hav en ' t b een able to  fin d a satis factor y  explan a tion of  it.
W hat  do es i t  m ea n t ot erm i na tea  ra y early,  a nd  whydo w e h a ve t o d o it ?
Bes ides, I notic edthat the  term  "fro nt-t o- backtraver sal"is  mentioned almo st e very time  th er e's  a  ment i on of"ea rly  ray te rminati o n". 
C o n c re tely how does fron t- t o -b ack trav ersalw or k( in the c as e o f ak d -tree  for ex ample)?
A:

F r on t- to-back  t ravers al  is  th e ide a  tha t when  travers ing a ray through th e  acceleration st r u ct u re,wewant to exa mine node s th a tare in fr ont,i. e .c loser to the camera ,before  othe r nodes. If y ou only wa n t the firs t in t er s ection with asurfa ce (as usu a l in ray  trac ing), th en if you g et an in ter sec tio n i n th e front nodey o u do n' t needtotravers e a nynod esbe hind it;as any p os si bl eint ersec t ion ther ewou ld  be  late r  thanthe o ne y ou  a l rea dy foun d .T h is s av es  tim e.Fo r exa mple ,  in  a kd-t ree, at e ach node  y ou  have a  splitting pl an e dividing  s pac e into t wo child  nodes. You would first descend  to  thechil d closertothe ca mer a , andonly i f noin ter s e ction s ar e f ou nd there d o you  desc en d to  the ot her child.
Early r a y t ermination se ems  tob e  a  te r mu sed  i n  th e context of volu me renderi ng .  W hen you're tra ve rsing a  ray th rough a mediu m that at tenuatesli ght, s uch  as fog, s moke, cl oudy liqu i ds, e t c. , the n b eyondacer taindistan c e t hereis nopo ssibil ity o fthe rayhaving any more effecton the  imag e.If you ha vet hic k fog wit h avisibility  of  10  mete rs, thenan o b je ct1 1 met ersa way canno t  b e s e e n. 
You can pr e c a lcu latethe distan ce a t which the atten u ation reaches99%o r  so  (i t  nev er  quite reaches  10 0% , but appr oa ches it exp onential ly ) . The re isno rea son toi n te r sect t he r ayagainst o bje ct s  farthe rth a n that , so  w hen us ing th e  acc e l eration structur e, yo u can s i mpl y dis ca rd anyn odes  beyond th at distance . In e ffec t, th e ray b ec omes a  li ne  segment t e rminatedat afixed l en gth.  If  it do esn
 to)_the device_represented by device_file using_a
 __ __ comma-separated list_of options.

 Q:

The_meaning of early ray_termination and front-to-back_traversal_in ray tracing

I'm new to computer graphics. These days I've been trying to understand_how_ray tracing_using_an_acceleration data structure works. I_came across the term "early_ray termination"_several times, I looked it over the internet_several_times too, but_I haven't been able to find a satisfactory explanation_of it.
What does it mean to_terminate a ray_early,_and_why do we have_to do it?
Besides, I noticed that_the term "front-to-back traversal" is mentioned_almost every time there's a mention of_"early ray termination".
Concretely how does front-to-back_traversal work (in the case_of a_kd-tree for example)?

A:

Front-to-back traversal is_the idea that_when traversing_a ray through_the acceleration structure, we want to_examine nodes that_are in front, i.e. closer to_the_camera, before other_nodes._If_you only_want the first_intersection_with a_surface_(as usual in ray tracing), then_if_you get an intersection in the front_node you don't need_to_traverse any nodes behind_it; as any possible intersection_there would be later than the_one you_already found._This saves time.
For example, in a kd-tree, at each node you_have a splitting plane dividing space_into two child nodes._You would_first_descend to the_child_closer to_the camera, and only if no intersections_are found_there do you descend to the_other child.
Early ray termination_seems_to be a term used in_the context of volume rendering. When_you're traversing a ray through_a_medium_that attenuates light, such as_fog, smoke, cloudy liquids, etc., then_beyond a certain_distance there is no possibility of the_ray_having any more effect on the_image._If you have thick fog with_a_visibility_of 10 meters, then an_object 11 meters away cannot be_seen.
You can precalculate the distance at which the attenuation_reaches 99% or_so (it never quite reaches_100%,_but_approaches it exponentially). There is no reason to intersect the_ray against_objects farther than_that, so when using the acceleration structure, you can simply_discard any nodes beyond that distance. In_effect, the ray becomes a line segment terminated at a fixed_length. If it doesn