so i gues we all tryed some ink. in real life or in cg.
and there are realy good engines and algorithms to render ink. but….
ok, so what i think about 3d max ink material is : its cool, but…
it kind of lacks controls. and ofcourse sometimes it does not do what u expext it to do.
ofcourse second complain is not that easy to change or corect, we will leave that to years of developement.
but first part is some new features, and we can talk about that.
Ok, so lets look at photoshop, if we go to draw whith brushes, we have hundreds of diferent brushes. like squere, dray brush wet brush, whatever… just diferent stuff. why cant we have it in 3d max? well or maya or xsi, doesnt matter.
so in my personal opinion what u nead to create a paint brush, is:
first is we nead to know where to apply outlines, and that we can find by having somthing like a alpha chanel or so, what i mean is imagine we have a scene whith only one sohere in it. so wehen we render it we could have one pass where we have all back as black pixels and foreground as white. there fore we can easily find edges. now i know there is much more to it. not only each object in scene has to have outlines, but also some lines inside object, i dono how one goes about it, but i am sute anyone who wrote somth like ink material renderer, knows this stuff. anyway we are not after that.
so lets say we already have a line created by this contrast analisis. now to apply photoshop or hand made brush we nead a direction. here we have some options. we can just randomly select dyrection and apply brush along our contrast line to that direction.
we can have it by analise normaly rendered image. lets say in some part shadows are very hard or color of object is dark so we have higher contrast in spcifick dyrction. that coud be a way to decide a direction.
but there are more interesting ways.
so lets read this document:
ok, here they use vector fields to describe how mesh topology should be done in a model.
its kind of complicated, but using this stuff they take models which has absolutely random, ugly mesh topology and remeshes them to have very nice edge loops and quad polygons. very nice. but cant we use same vector fields to get dyrections of brush strokes?
i am sure some research is already done on thios, i seem to remember reading such article, it had examples whithj egg, and rotating camera around it, pls, someone give me a link to add here….
but . lets say we know where our brush must go and, which dyrection, now we just chek the lenght of line and our bruch will act acording. what i mean here is when u use brush, first u usualy have a drop, and start whith fat line, which goes finer and finer till the all the ink in brush is used and nothing more is drawen.
we all know how this works in photoshop using dynamick brushes. lots of presets and options to explore.. why not in 3d?
so lets analise what exactly we have in brush stroke?
1 a start of brush, kind of a peddle.
2. normal line which goes smaller in whith.
3. lines brake up cos of crapy brush.
and the wet paint folows garvity.. and drips.
the secont picture is very time related.
anyways thuse could be some of ideas fr writing new ink renderer / material / shader.
well its not exactly a photorealistick rendering but now we are all so interested in non photo real renderings, so this is some ideas around it.
ps. what hapends when camera, or object moves fast? well we all have seen manga drawings and anime films whit thuse motion lines. now if we take a pedle of ink and move it very fast it would do something wouldnt it?
i mean… well lets have a look at picture:
well again, anone interesten in writing it?
i am interested in further consulting. or feadback, if anyone understud what i am talking about.
and again, noone knows how exactly it would look, but i hope it would look very interesting, good (insert further braging here..)
pss. some more links tosee:
http://visgraph.cse.ust.hk/MoXi/ (link no longer works :((()
you can also wisit my portfolio.
dont like english? u can (try) readig it in lithuanian or anny other language here! alternative, has no lithuanian :(