Well, most of the good rotopo tools I’ve seen behave in a different way compared to regular modeling tools. They have special, higher level tools to modify the mesh flow.
That said, the display is a big important part of what would make retool work better. We even discussed doing something during the Code Quest to fix/improve the display of meshes for rotopo, but ran out of time.
There’s no good way to set up the viewport for rotopo currently, so it’d be great to do something here.
The main issue is one of design - how do we expose this? As a viewport thing? An object display setting? You’d only want it for one object, so it doesn’t fit well being a viewport shading setting.
I don’t think we need an entire template - we could just have a Workspace for it.
But the question remains, how to implement it? As a viewport setting, mode setting or object setting?
Currently, we have something called Hidden Wire - we’ve had this option for years. This was meant for retopo and can be enabled in Edit Mode -> Overlays. But it’s not a very good display and not very discoverable.
The retopo mesh gets lost inside the the object you are trying to retopo, and you can’t see the difference between wires that have faces, and just loose wires.
It’s also limiting that it only exists in Edit Mode. It means the retopo display goes away when you exit Edit Mode.
Yes I use it all the time, don’t know why people don’t use it.
I think, people could do their own template for retopology, it’s pretty easy now IMO.
What’s lacking is some base tools to start a retopo.
The new active poly tool can be enough for retopo in fact, just need something to start it on a reference like
If object selected > when clicking on the active tool, activate snap face, add shrinkwrap etc.
Oh my … I don’t want to derail the discussion about how to best implement a retopo shader - but I’ve started posting up the most important tools from my perspective (for further down the line). Sorry - I’ll just post this as a “this would be cool if you ask me” and then write up a second post just for what I think a topo shader/setup might work (which is essentially showing how modo does it and then maybe derailing a little more towards how it could work in blender). Before that, though … Topo tools:
Modo sort of does the same thing, here. It uses basically all the existing tools from the repertoire and creates presets for them. In fact I can boil down Modo’s retopology workflow to four tools which carry most of my work:
The topology pen
surface snapping in regards to normal vectors, not only screen projection
a standard line pen to create edges and connect them afterwards
an edge ring tool that creates (spline)edge rings around geometry
The most versatile tool is the topology pen as it combines some very important functions in one preset without much need to switch over. Modo’s topopen is able to:
create single quads
extrude single edges
extrude a row of edges up to a certain degree
insert edge loops
slip edge loops
snap-weld vertices or edges within an adjustable distance.
move single vertices, edges or faces by simply click-dragging (no prior selection needed)
The standard pen tool simply creates connected polylines that can afterwards be connected to polypatches. Nothing overly fancy - mostly like Ctrl-clicking a vertex in blender. It’s just nice that shift-click starts a new polyline without the need to deselect or duplicate.
The third one is the ability to project geometry onto a surface without a modifier or a vertex-selection. Basically the surface normals dictate when geometry sticks to the surface of a mesh. Even if it is for example scaled down around the geometry:
The last one is a tool for tube-shaped geometry projecting a countour around the mesh. The countour can either be a set number of vertex cuts or a spline projection which can then be bridged with a flexible number of edges:
To be honest, the Hidden Wire display is really bad. We could make this so much better. We could:
Rename to Retopology Overlay
Make it so faces always display on top of the underlying surface, so it doesn’t get lost inside it.
Make faces display semi-transparent, so you can see difference between faces and loose edges.
But really it’d also be great if we could add tools, such as contours, a kind of polypen for drawing a path of quads, and so on - either in Edit Mode or a special Retopo mode
isn’t retopo an activity that only makes sense in edit mode? Pardon my ignorance, but I don’t actually do much retopologizing of things, so I’m not sure of the utility of a retopo view in object mode, or particle edit mode, or sculpt mode.
Sure, you only do the editing in Edit Mode, but it could still be nice to see your display outside it, while you judge your work. You might do your retopo work in different objects and join them later, for example.
It’s not the biggest issue, but it’s related to how we access this display setting - if it’s a mode-dependant setting or not.
Would it make sense to implement the “retopo shading mode” as a material that the user can apply? Shouldn’t it then show up in all modes, maybe even on renders?
Sure, you could do this today using Eevee, sort of. But besides being impractical, it still doesn’t help making sure the correct mesh is displayed on top (they will still intersect), and it’s also slower than something that would work in Solid mode too.
Retopology currently with hiddenwire+xray is very confusing and it gets more and more confusing as you approach in your work and have wires showing from backface of the model
Sorry for the unexciting meshes - I’m working off of library models for the sake of demonstration, here.
What Modo does is pretty simple, yet also very effective. Simple in terms of usage, that is.
First and foremost there is an option to set the viewport shading to “retopo mode” so that no single object needs to have a dedicated shader. When “Topology Mode” is enabled the selected mesh(es) is(are) being drawn in retopology shading, no matter if it’s currently being edited or not. And they stay in topology shading until another mesh is selected.
Topology shading has pretty much two major attributes:
all front facing polygons are drawn translucent but always on top of any geometry. All backfacing geometry is always drawn wireframe without any polygon fill.
Front facing polygons can self-occlude backfaces but never occlude any unselected geometry.
We already have the shiny new multi-object editing in 2.8 so that part should not cause much confusion any more.
In action it looks like so:
(edit2: there we go)
I also kinda like @fiendish55’s idea of merely overlaying the active topo geo. Backfaces are nice but really the intersection of the base meshes is the main overall problem that causes the most pain for now.
The one exception (also kind of pleasant once you’re used to it): is that selected faces will always shine through geometry - slightly less highlighted if occluded. That would certainly complicate things, though so I just mention it as a Modo specific convention that should be up for debate some time later, later, later … probably
Sidenote: Modo’s advantage here is that it also already has a way of setting up active meshes differently than inactive meshes. There are drawing options for “active” and “inactive”. They are pretty much the same options but dictate how selected and edited meshes are drawn compared to unselected meshes.
Some very good ideas and arguments for a possible implementation. Cool.
As long as we get a retopology shading display that is consistent and independent of individual settings that also affect modeling or selections everything beyond that can follow later on, I think.
As I said: Blender is already capable of drawing polygons in a retopo friendly way. It’s just that the required settings for each mesh are all over the place or that the shading mode (like ‘limit selection to visible’) also influences the way selection and modeling behaves.
I absolutely agree: Ideally a topology shading mode should be be central, working across meshes and be independent of how the current modeling and selection tools behave.
More tools can safely follow later on when there is time.
I really hope BGL will make it into 2.8 because otherwise tons of really good addins will have a major issue updating or showing nice info about what the addon is doing. There are tons of them which use a modal operation so a user is informerd in the Viewport whats going on. It would be a shame if this goes to waste now.
I also use an addon which uses an external renderer which makes it possible by using BGL to IR render live in the viewport. Even border render works, if this doesnt make it through that would be such a putty.
PS arent items like box render and box select also using BGL it self? I mean it does look like that BGL as well.
It seems everything is working nicely now. When turn to Wireframe Display mode it works as in 2.79 with X-Ray active by default.
The only thing I do not know if it is working correctly is that when you are in Wireframe Display mode, X-Ray slider under Shading options looks grayed out (although it works). This until you switch to X-Ray in another Display mode and then there it lights up.
X-Ray and “show whole scene transparent” seems very close to a very good shading but again doesn’t have self occlusion or faded backfacing to better distinguish geometry in the back of the mesh.
