Mu ltip rocessor Iso-surface Volume Reudering

It to be com puted t he ready b uffer is d l(~ked to S("(' if t.he computations Me really necessary, if tl u' ray
.y teruuua.....1 t he compntat.lo nn Me s kippe... l. T his spt-"t-'tl!'l u p the re ud N illK process by a l a r~p amount.
. re ndermg is by its very na t ure very d ata int e nsive. For this reason t he ISVR ,\lgoril hlll uses a binary
hiuru-y shell is also chec ked t o avoi d unneoeearv computations . \Vhell t he lso s ur face is rt...-on.st.ruct e d a ll
u- is used to find "he exact locnt.iou of t he s u rface. If based on t lu- val ues ill II... dataset we call d ('INlIlinc
is 110 lso s u rface between eight neighboring voxels, we can s kip t.hnt part icula r s pre-e. These sma ll space;
ght neighboring voxr-ls will be called a cdl for the res t of this p ajlN. Cenerutiug 1,1](' binary s hel l r-an he
fast compared to the res t of t he co m putations and therefore using the hln ar v shel l is w ry efficient. Another
o f the biunry shell is t ha i, it only needs to he generated when t he iso va lue is changed. T his allo ws t he­
10 skip runny cells whose vox c-ls will 110 IOIlF;!'T be Fetched. This reduces t.hr- amoun t of' dnl.n t.hnt mu st I",
un t,ll!' mai n nu-mcry, which ltb~(J I:II)f'f'(i s up t IL!' renderi ng process.
a. .I\ I U LT I PROC E SSOR R E N D EllIN G
ndering w it h muh.iple processors on a genera l purpose comp ut er if; not only It mati or o f makin g t Il!' .~ I) f1 wa re
rltiple processors sirnultuneuuslv. The proper t ies of I)lt' hardwa re should he t akr-u into alTOUII!. , L('P wlu-u
tn Ill' d OIIP , ..... hir-h a ll o ws tho ('o m pul t>r to be us, ... ) fo r other t usks.
laq!,.· :\IlIOUII\'S of data need to IIf' sinn ed . sltarf't! IIwlnory segl ll'· nl..rs in e1\(,I. clust er
Clu ster
k times
-e - > : , __--=:C,liu"tcr
socket
--. D process
:nderJo h o shared memory seg ment
,
n times I
, n titiles
Data 1 V Data
nderJ(lh Manager : 17 Re nd e rJo h
,, I Manager
oady Data :, ,: : Ready : [ Data
,
ullc r , Segment I , Buffer : Se gment
, ,, I ' ,
, , <
~ ~ ~ ~~ ~~: I~~~ ~ ~~ ~ ~ ~~~~~~~~- -------- - ~
I Se h~dl~le r I Image
Buffer
Fig ure 4 . The software arr-hit-x-t.ure.