Cre­ate hair in 3ds Max and ornatrix

The goal of this test ren­der was to ob­tain a re­al­is­tic-look­ing hairstyle us­ing an Ornatrix, 3ds Max and V-ray work­flow

3D Artist - - COMTENTS -

Make a re­al­is­tic-look­ing hairstyle

Hair and fur gen­er­a­tion is ar­guably the trick­i­est do­main of char­ac­ter cre­ation in 3d. it’s one of those things in the CG world that is dif­fi­cult to get around. if the hair feels wrong the whole look of the char­ac­ter will be off. it’s easy for the process to go side­ways be­cause of how dif­fi­cult it is to find the right ap­proach be­tween the com­plex­ity of the work­flow, the mul­ti­tude of pa­ram­e­ters and the weight it tends to add to your scenes and ren­ders.

think­ing about your steps be­fore­hand is key and it can ac­tu­ally save you a lot of time and frus­tra­tion. in this 15-step tutorial we’ll break down some tech­niques used in the in­dus­try by some of the big­gest an­i­ma­tion and VFX stu­dios. For the hair cre­ation we’ll use Ornatrix and V-ray in 3ds Max, but keep in mind that once you have the base prin­ci­ples down you’ll find your way no mat­ter the tools you’re choos­ing. the pa­ram­e­ters and the way they’re wired will change, but es­sen­tially the main steps re­main the same. re­mem­ber to be pa­tient. hair cre­ation is del­i­cate work and for it to ac­tu­ally look good you’ll have to put some time into it, and this is en­tirely nor­mal. have fun along the way, and don’t be scared to ex­per­i­ment!

01

Sculpt a ref­er­ence vol­ume in Zbrush it is es­sen­tial to know where you’re go­ing in terms of vol­ume and de­sign. that’s why it can be in­fin­itely ben­e­fi­cial to have an ac­tual vol­ume ref­er­ence in your scene that will help with plac­ing your guides later on.

Zbrush is also a good place to ex­per­i­ment with the shape, the flow of the hair, the di­rec­tions and the main strands. none of it has to be pre­cise though.

02

Cre­ation of the emit­ters the emit­ters are the pieces of ge­om­e­try from which the hair will be gen­er­ated. You gen­er­ally want to start from the model of your char­ac­ter for that. Make sure that ev­ery­thing has UVS for the tex­ture maps later on. take your model and du­pli­cate it. sep­a­rate the scalp, eye­brows and eye­lashes and keep only the poly­gons that you are go­ing to use.

03

De­fine the parts at this point you are go­ing to think about the dif­fer­ent parts of your hairstyle. Of­ten it is more sim­ple to have your parts on dif­fer­ent ob­jects and this will al­low you to have a much bet­ter con­trol over the zones where the hair is part­ing, us­ing maps. Ornatrix does al­low you to part hair within the same hair sys­tem us­ing groups or the part­ing tool, but you some­times end up with an odd bold and un­re­al­is­tic area where the hair splits. We’ll end up with seven dif­fer­ent hair sys­tems: right part, left part, rebel hair for right part, rebel hair for left part, baby hair, eye­brows and eye­lashes.

04

Groom the main strands and shapes Cre­ate a ball of fur on your scalp emit­ter. Fo­cus on one part at a time and start with a very small amount of guides. When you add guides later on these will be in­ter­po­lated with the ex­ist­ing ones so you’ll save some time. in the Guides from sur­face mod­i­fier, set the root Count at 10 and then num Points at 50 to have some def­i­ni­tion. in the edit Guides mod­i­fier in roots mode, you can select guides and move them around, re­move or plant new ones. start plac­ing your guides at the outer edges of your hairstyle and brush them one by one in or­der to have the main vol­umes down with the help of your ref­er­ence sculpt.

05

Par­al­lel lay­er­ing tech­nique now we are ac­tu­ally go­ing to need more guides to have a good in­ter­po­la­tion and bet­ter con­trol over our vol­umes.

as you start plant­ing more guides, try to place them in par­al­lel rows. this will stop your gen­er­ated fi­bres look­ing like they in­ter­pen­e­trate. start at the base of your neck and add lay­ers on top of each other, re­spect­ing the hair’s move­ment and vol­ume. this will al­low you to have a clean base to work from.

06

Ter­tiary shapes and de­tails You can now start adding de­tails and ad­just­ing vol­ume. You are most likely go­ing to work with groups of guides for this step and not one at a time. You might want to ac­cen­tu­ate the loop at the top of the fore­head, or maybe you want to iso­late a strand and tighten the swirl at the tip. do these ac­tions with a big ra­dius brush and a low strength to avoid lit­tle ir­reg­u­lar­i­ties and dam­age to the flow of the hairstyle.

07

Groups, channels and maps as we dive into fi­bre gen­er­a­tion and in­ter­po­la­tion we are go­ing to use a range of pa­ram­e­ters to con­trol the dif­fer­ent ar­eas. to do that we can ei­ther as­sign groups in the edit Guides mod­i­fier, use the paint brush to cre­ate dif­fer­ent channels or sim­ply cre­ate black-and-white maps that will use the UVS of the emit­ters. a good ex­am­ple would be the dis­tri­bu­tion Map in the hair from Guides mod­i­fier. We can use the view­port can­vas to paint on the scalp where we want the hair to grow, and then plug the tex­ture in the map slot.

08

Pri­mary clump­ing One of the hard­est things to recre­ate with long hair is this mul­ti­tude of dif­fer­ent size strands. strand Clus­ter­ing helps a lot with that, but to achieve more re­al­ism we want dif­fer­ent sizes of clus­ter­ing. add a hair from Guides mod­i­fier with a ren­der count of 5,000, fol­lowed by a strand Clus­ter­ing with a Global size of 10, a soft Value Curve and a Guides from hair on top of that to turn those 5,000 clus­tered fi­bres back into guides.

09

Hair from Guides Be­fore turn­ing the guides into hair again we are go­ing to stack in a light strand Frizz to give the clus­ters a more or­ganic look. then the hair from Guides mod­i­fier is go­ing to con­sist of find­ing the right hair count and the right in­ter­po­la­tion. in this case, we are go­ing to use the affine in­ter­po­la­tion and leave the Guide Count at three. For op­ti­mi­sa­tion pur­poses you can paint dis­tri­bu­tion maps that will be white to­wards the outer edges of your parts and much darker at the cen­tre. You can also make the right and left parts over­lap a bit at the part­ing to avoid a bald spot.

10

In­ter­po­la­tion of fi­bres We are now go­ing to use some ex­tra mod­i­fiers to make ev­ery­thing look a bit more dy­namic and nat­u­ral. i get the best re­sults with dif­fer­ent Clus­ter­ing mod­i­fiers, the Frizz and the Curl­ing. strand Curl­ing is used very softly in spi­raloid mode. strand Clus­ter­ing is used with a size of 10 again and then hair Clus­ter­ing is used with a large num­ber of Clumps (be­tween 1,000 and 2,000) to cre­ate very small strands. You might need to try a lot of dif­fer­ent seed­ings here to find some­thing you like. Fi­nally, add a light strand Frizz on top.

11

Ren­der set­tings You must con­sider that the hair thick­ness and V-ray’s an­tialias­ing will in­flu­ence each other. this is gen­er­ally where things start to crank up in terms of ren­der time. run some tests to find what works best. here we are us­ing a global ra­dius of 0.01 with a curve, and a noise thresh­old of 0.005. We’ll see how to cheat a bit later on with the opac­ity of the shader to give some ex­tra soft­ness. You can also add a strand Length mod­i­fier with a low ran­domise pa­ram­e­ter to soften the tips. don’t for­get the V-ray­or­na­trix­mod on top.

12

Rebel hair adding an ex­tra hair sys­tem of rebel hair and fly­aways for each part makes a dif­fer­ence in terms of re­al­ism. hav­ing it on a dif­fer­ent ob­ject will al­low you a lot more ease and free­dom in your pa­ram­e­ters. this sys­tem is made from the same guides (just du­pli­cate your ob­ject). it has about a third of the hair count, a light strand Clus­ter­ing, a strand Length and most im­por­tantly a strand Frizz with a much big­ger amount.

13

Baby hair For the baby hair groom en­tirely new guides on a dif­fer­ent hair sys­tem. this soft, fuzzy hair around the face has an­other length and di­rec­tion from the rest of it. it helps also greatly with blend­ing ev­ery­thing to­gether and adding some im­per­fec­tions. For the in­ter­po­la­tion, we’ll use a strand Frizz, a strand Curl­ing and a strand strength with a ran­domise at 0.8.

14

Eye­brows and eye­lashes to save some time here we will work on one side only and then use the strand sym­me­try mod­i­fier. eye­brows and eye­lashes have their own emit­ter each. the trick for very short hair is to use a small root Count (two or three max­i­mum) to make groom­ing ef­fec­tive.

don’t worry with guide length ei­ther, as you will con­trol ev­ery­thing with maps. here we use a hair Clus­ter­ing, a strand Frizz and a strand Length for the in­ter­po­la­tion.

15

Hair ma­te­rial We will be us­ing the V-ray­hairmtl to cre­ate the shader. Be mind­ful of the colour vari­a­tions. Gen­er­ally the hair shade isn’t the same ev­ery­where, and it’s darker at the roots. We’ll recre­ate that with the V-ray­hair­in­fo­tex map, both along the strand and across the UVS. For the colour vari­a­tions sim­ple check­ers maps of dif­fer­ent colours are used. You don’t want the tile to be too small here, or the dif­fer­ent colours will just blend with one an­other. We’ll lessen the opac­ity along the strand to soften the look and bal­ance the an­tialias­ing at the tips. to save some ren­der time, you can tick the Opaque for shad­ows and Gi boxes in the shader op­tions.

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