OpenFab:AProgrammablePipelineforMulti-MaterialFabricationKirilVidimceˇSzu-PoWangJonathanRagan-KelleyWojciechMatusikMassachusettsInstituteofTechnologyFigure1:Threerhinos,definedandprintedusingOpenFab.Foreachprint,thesamegeometrywaspairedwithadifferentfablet—ashader-likeprogramwhichprocedurallydefinessurfacedetailandmaterialcompositionthroughouttheobjectvolume.Thisproducesthreeuniqueprintsbyusingdisplacements,texturemapping,andcontinuousvolumetricmaterialvariationasafunctionofdistancefromthesurface.Abstract1Introduction3DprintinghardwareisrapidlyscalinguptooutputcontinuousState-of-the-art3Dprintinghardwareiscapableofmixingmanymixturesofmultiplematerialsatincreasingresolutionoverevermaterialsatupto600DPIresolution,using,forexample,pho-largerprintvolumes.Thisposesanenormouscomputationalchal-topolymerphase-changeinkjettechnology.Eachlayerofthemodellenge:largehigh-resolutionprintscomprisetrillionsofvoxelsandisultimatelyfedtotheprinterasafull-resolutionbitmapwherepetabytesofdataandsimplymodelinganddescribingtheinputeach“pixel”specifiesasinglematerialandalllayerstogetherde-withspatiallyvaryingmaterialmixturesatthisscaleischalleng-fineontheorderof108voxelspercubicinch.Thisposesanenor-ing.Existing3Dprintingsoftwareisinsufficient;inparticular,mouscomputationalchallengeastheresultingdataisfartoolargemostsoftwareisdesignedtosupportonlyafewmillionprimitives,todirectlyprecomputeandstore;asinglecubicfootatthisresolu-withdiscretematerialchoicesperobject.WepresentOpenFab,ationrequiresatleast1011voxels,andterabytesofstorage.Evenforprogrammablepipelineforsynthesisofmulti-material3Dprintedsmallobjects,thecomputation,memory,andstoragedemandsareobjectsthatisinspiredbyRenderManandmodernGPUpipelines.large.Thepipelinesupportsproceduralevaluationofgeometricdetailandmaterialcomposition,usingshader-likefablets,allowingmodelstobespecifiedeasilyandefficiently.Wedescribeastreamingarchi-Atthesametime,itischallengingforuserstospecifycontinuoustectureforOpenFab;onlyasmal