[Bf-committers] Bringing Freestyle back to Blender 2.8

[Jacob Merrill]

many people are using cell shading in realtime to produce cartoon  renders
in real time, maybe this could be a path to realtime npr?

also, I seem to recall a geometry shader produce can outline almost
instantly?



On Aug 12, 2017 5:54 AM, "Brecht Van Lommel" <brechtvanlommel at pandora.be>
wrote:

> Regarding relying on static material properties, I think those can be kept
> then. The diffuse/specular/hardness could be moved into the Freestyle Line
> panel and only used by Freestyle.
>
> On Thu, Aug 10, 2017 at 4:06 AM, Tamito KAJIYAMA <
> rd6t-kjym at asahi-net.or.jp>
> wrote:
>
> > Hi Brecht,
> >
> > Many thanks for the detailed replies, and excuse me for the delayed
> reply.
> >
> > I agree that the first thing to do to keep Freestyle functional in the
> > Blender 2.8 code base is the removal of Freestyle's dependency to the
> > object/mesh data structures of the Blender Internal.  Freestyle in
> > Blender 2.7x and earlier receives a bunch of tris/quads through the
> > Render::instancetable (that is, a linked list of ObjectInstanceRen
> > data).  Freestyle doesn't really have to care about many details of
> > Blender scene data, mesh modifiers, animation, render settings, and so
> > on---instead, the ObjectInstanceRen data allow Freestyle to simply deal
> > with a final set of polygons resulting from all the rendering related
> > details already addressed by the Blender Internal and Cycles.  If there
> > is a convenient way to do the same in 2.8, then I expect the dependency
> > removal would be straightforward.  Otherwise, the work might be a bit of
> > hassle.
> >
> > As to the material system, Freestyle currently relies on static (not
> > node-based) material properties such as diffuse color, specular color,
> > and some other props.  In addition, there are a few Freestyle-specific
> > static material properties such as line color, line alpha transparency,
> > and line priority (plus, line thickness is to be added in the future).
> > Freestyle employs static colors as solid line colors no matter how the
> > material is lit by various light sources and seen by the camera.  If
> > everything is defined by material nodes in 2.8, then a few extra nodes
> > specific to Freestyle are necessary.  At the moment Freestyle doesn't do
> > anything with material nodes when retrieving material props.  So, again
> > everything in nodes might imply a substantial amount of work on the
> > Freestyle side.
> >
> > As far as Eevee gives Freestyle a render buffer to which line components
> > are composited, that's fine and I expect very little work there.
> > Freestyle performance is far from real time, so I would say Freestyle
> > rendering in the viewport is out of scope in short- and mid-term ranges.
> >
> > Best regards,
> >
> > --
> > KAJIYAMA, Tamito <rd6t-kjym at asahi-net.or.jp>
> >
> >
> > On 2017/08/01 9:47, Brecht Van Lommel wrote:
> > > Hi Tamito,
> > >
> > > Blender internal and its material system have not been removed yet, but
> > > they are planned to be replaced by Eevee. I don't think anyone has
> > actually
> > > gone though what that entails in detail, since there is indeed code
> like
> > > Freestyle and the texture system that rely on it even when not
> rendering
> > > with BI.
> > >
> > > I expect the first thing to keep things functional would be to stop
> > relying
> > > on the BI object/mesh data structures, and rather get geometry directly
> > > from the Blender object/mesh data structures. This should be easier now
> > > than it was when Freestyle was initially implemented, since there are
> now
> > > functions like BKE_mesh_new_from_object to get a mesh from any type of
> > > object. Some of this stuff will likely still evolve some as the
> > dependency
> > > graph is being worked on.
> > >
> > > Materials I think would all be defined using node graphs, which should
> > > already work with Freestyle? But for NPR work is needed to get back
> some
> > > functionality from Blender Internal. There is no design for that yet as
> > far
> > > as I know, would be interesting to get some idea which extra nodes
> Eevee
> > > needs.
> > >
> > > In terms of integrating with render buffers, I hope the way it works
> with
> > > Cycles as an external engine can also work for Eevee. So Eevee could
> > > deliver render buffers the same way as Cycles and freestyle could
> > composite
> > > on top of them in the same way. Beyond that it would of course be
> really
> > > cool if Freestyle could work in realtime on top of Eevee, showing
> OpenGL
> > > accelerated line drawing in the viewport, but I guess that would be
> > almost
> > > a full rewrite of Freestyle.
> > >
> > > Regards,
> > > Brecht.
> > >
> > >
> > > On Mon, Jul 31, 2017 at 4:26 PM, Tamito KAJIYAMA <
> > rd6t-kjym at asahi-net.or.jp>
> > > wrote:
> > >
> > >> Hi,
> > >>
> > >> I would like to discuss with the viewport team what precisely would be
> > >> necessary to bring Freestyle back to Blender 2.8.  I was informed that
> > >> the old material system and the Blender Internal renderer have been
> > >> removed so that Freestyle won't work anymore.  The idea is to have a
> > >> development plan of what needs to be done and until when.  Thoughts
> and
> > >> suggestions are much welcome.  Thanks in advance for the input.
> > >>
> > >> Best regards,
> > >>
> > >> --
> > >> KAJIYAMA, Tamito <rd6t-kjym at asahi-net.or.jp>
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