- [Zach] Hi, Zach here. And here's a retopology video which I wish I had when I learned retopology in Blender
using only free tools which are shipped with Blender by default. First, open up the object
you wanna retopologize and let's disable a few viewport overlays and the gizmo here to
have a cleaner, 3D view. I'm using Blender 3.2 alpha here but this workflow should also work in basically any upcoming Blender version or older Blender versions. Then press F4, go to preferences add-ons search for BS enable the Bsurfaces add-on search for F2, enable the F2 add-on and search for LOO and
enable the loop tools add-on. Select your sculpting, press N go to edit, and here we find the Bsurfaces add-on. Then press the initialized button to create a basic retopology setup. This will now create an empty mesh object with the Shrinkwrap Modifier on it. We will automatically
switch to the annotate tool and the placement is set to surface and the face snapping is
also enabled automatically. The snapping and the
Shrinkwrap Modifier helps us to keep the new geometry on
the surface of the sculpting. Then let's zoom in here a bit
and start drawing your strokes like this, and then click on add surface. This will now generate the first geometry. Then let's open up
operator panel down here and here you can change the subdivisions for the horizontal axis and
also for the vertical axis. And you can also make it cyclic
by checking Cyclic Cross. Then to make the workflow a bit easier for us enable in front. This will always show this geometry in front of other objects and here we can also change
the color if you like and you could even change the opacity by changing the alpha down here but I like the default value. Since I'm working on a
symmetrical mesh here, I want to have everything I do on one side mirrored to the other side. For that let's click on add
mirror and other modifiers which will add the mirror
modifier, but also a subsurf and a solidify modifier,
which we can remove here. We only keep the mirror modifier. Also, if we switch back to edit mode and I extrude something to the center here you can see that this sticks
to the mirroring access here and that's because clipping is enabled. However, it can be a bit annoying to always see the mirrored
part on the other side especially when you have
a lot of geometry here this can get quite messy. One thing we can do is to
enable backface culling which will make the back
side of a face transparent as you can see here. However we can also disable
the mirror modifier display in edit mode by checking this button here. And the cool thing is the
mirroring still happens, the clipping still happens,
but we can focus on one side of the mesh without getting
distracted from the other side. Then to make the Shrinkwrap
Modifier work a bit better change the wrap method to
project and enable negative. Now back to the Bsurface add-on. There are now two ways
to add new geometry. First of all, we can add loose geometry make sure everything is deselected by pressing Alt A and then hold down D to temporarily enable the annotate tool. And then you can start
adding more strokes here. Then again, click Add Surface which will generate this new surface. Make sure Cyclic Cross is disabled here and for now I wanna keep the geometry relatively low resolution. We can add more loop cuts and so on later. Another way to add geometry
here is to select one edge here make sure edge selection is enabled and then you can draw
additional strokes here and add the new geometry. And this will then
automatically be connected to the selected edge. When using the Bsurface add-on there is just one important thing
you have to keep in mind. When drawing the strokes let's hold on D and draw the strokes. You have to always draw them
into the same direction. If I now draw this stroke
here into the other direction and then here again, let's
go with the other direction. And I now generate this geometry. You can see that this
edge here is now flipped which I have drawn to the other direction. You can relatively quickly fix
this by selecting this edge press S to scale it and basically scale it into
the opposite direction. And by the way, if you
accidentally made something wrong with these strokes, you
can simply delete them by holding down D, right
mouse button click, and then he erases over here. Or if you click and hold
on the annotate tool you also find the annotate eraser and then you can erase these strokes. And then if you continue
here, it works as expected. Besides the Bsurface add-on we can also use the default
tools in Blender, for example we can extrude with E or we can extrude with
holding down Control, and then right clicking then it will extrude to
the position of your mouse. Then with Control R we can add new loops to existing geometry, and
you can see depending on where I place my mouse,
we get this preview. Then you can either scroll the mouse wheel or press page up and
down to add more loops, then Left Click to confirm. Then you can slide them around. Then with Left Click, you
can confirm the new position or simply Right Click to
snap them back to the center. You can remove loops by
having edge selection enabled and pressing Control X to dissolve them. And you can also slide existing geometry by selecting it pressing
double G to slide it around. And this also works with
vertices when having the vertex selection enabled. Then as you maybe remember,
we also enable the F2 add-on which is also a great addition to use in the retopology process. Let's extrude a few faces here and now let's imagine
we wanna add another row of faces up here. For that simply select
one vertex in a corner make sure vertex selection is enabled and then press F to just add a new face. And we can do it again
and again, after this you can automatically tweak
this new added vertex over here and with Left Click place
it, and then add a new face. This is a fantastic
workflow to quickly fill in more geometry as you can see. Then we also enable the loop tools. When you press N, go to edit you can find the loop tools over here. And this offers a few more
options to adjust your geometry. A few of them, which are pretty cool for example, when you
selected a circular shape here you can make a perfect circle out of this. Or you can relax the geometry
to kind of smooth it a bit. Or if you wanna make all
edges along one edge loop the same length you can
click on the space button. Now, each of this edge
has exact same length. Now keep in mind that face
snipping was enabled over here as we initialized the Bsurface mesh. You can always turn it off it if you like, but let's keep it on here. And now when I select
geometry and move it around this will automatically be projected onto the surface from our view. This is very useful. However, this can also cause some issues. For example, if I view the mesh from here press G to move the vertices around it looks as everything is nice. However, now you can see it was projected on this surface here. So always make sure to view the geometry which you are moving around
from the right perspective. Besides snapping over here we have also the Shrinkwrap Modifier which also helps us to
project the geometry of the retopo mesh onto
our sculpting over here. And this works by selecting
the target down here which was automatically done
by the Bsurfaces add-on. However the Shrinkwrap Modifier
works a bit differently than the snapping. Let's disable snapping up here and also let's disable the
Shrinkwrap Modifier for a second. And then let's move one
vertex a bit further away from the geometry. So it's floating in space up here. However, when I now reenable
the Shrinkwrap Modifier this vertex gets projected
onto the near lying surface. If I disable this button we can still see the original
position of this vertex. And you can see how this is projected when I move this around. The problem here when
this button is enabled and I now move the vertex around I don't know where it
originally was positioned, and this behaves a bit weirdly. And this is why we enable snapping to always project it directly onto the surface when
we move a vertex around. However, there's a problem. When we use certain tools, for example like adding a loop cut here. This is where the
Shrinkwrap Modifier shines because here all these vertices will not be projected automatically
using the snapping. If we want to do this, we had
to press G to move them again. But if we don't do this you can see how the
Shrinkwrap Modifier projects this new loop onto the surface. So this is why the Shrinkwrap
Modifier is useful. However, every now and then
doing the retopology process I duplicate and apply
the Shrinkwrap Modifier. So we go to object mode, duplicate it. And for the top Shrinkwrap
Modifier, I simply apply it. Then all the vertices
which are maybe floating in space still will be re
projected onto the surface. So we are actually affecting
the original mesh here. Now, if I enable and disable
it, everything is in place. So if you ever notice that some vertices are
behaving a bit weirdly just duplicate and apply
the Shrinkwrap Modifier. Also one important note here up here auto merge vertices
is enabled by default. That means if you move two
vertices close to each other they will be merged. This is of course, super cool sometimes. If you have something like this and then for example, extrude over here then these vertices here
will be merged automatically. However, this can also cause problems. When you move geometry
a bit close together it will also merge it maybe
even if we don't want. You can reduce the threshold over here so you have to really
move them super close to merge them together. Or if this is annoying you can just disable
it completely up here. Now we know how to use the tools but how do we actually place
a new geometry on the surface? The general idea here is to
follow the flow of the shape and make sure that areas
that deform later on like the eyelids, for example have a certain topology to be able to perform the deformation like opening and closing the eyelids. So you usually, I start with
defining important loops first without connecting them. Like here a circle around the eyes a loop around the mouth,
and then also some loops along hard edges or important landmarks. Here I keep the resolution
relatively low to keep it simple. We can add more loop cuts later on. Then when all the major loops are in place I connect them by a filling in open areas. In general I try to use quads only, meaning faces with four sides. This allows us to get
nicer results later on if we subdivide the mesh but it especially helps
us in the editing process. Since only quads allow us
to quickly add loop cuts for example, or later on in the UV unwrapping
process to easily add seams in different areas. In short quads will make
your life a lot easier. So try to avoid tris or n-gons meaning faces with less
or more then 4 vertices. In terms of how detailed you
should make the retopology it is of course up to you but you should at least
add as much geometry that all important shapes are included. Of course you don't need to focus on retopologizing small scales
or surface details here but we need the eye
shapes, the mouth shapes maybe some topology for the
nostrils and so on and so forth. And as always, if the
resolution is too low later on we can always subdivide the mesh. Another little thing
that can happen when you retopologize your mesh. For example, let's add
more geometry over here using the Bsurfaces add-on, add surface. And now you can see,
this also is transparent. So we are seeing the backside
of these faces down here. So we have to flip them for that hover above one vertex of this
area, press L to link select so everything which is
connected will be selected. And then you can press Control Shift and to flip this geometry. Then let's add one loop over
here, similar as at the top and then we can simply
fill this area with F. Now when your retopology
is done, of course here I just retopologized the
top part of the head. Let's go back to object mode. Let's select the select tool here duplicate the Shrinkwrap
Modifier and apply the first one. So everything is reprojected
onto the surface. However, the mesh looks still
a bit messy as you can see we have some closer line faces, bigger areas and so on and so forth. And in order to fix this let's actually switch to sculpt mode. And here let's extend this a bit. We have this slide relax tool. And the cool thing about this is that this allows us to
move the vertices around without affecting the
volume of the object. So we are just moving the topology. So and by default, we can
just move things around. Let's reduce the strength
a bit, as you can see we can change this to pinch which like squeezes the geometry together. And we can also change this to expand which will push the geometry
away from each other. But the best tool here is
to simply hold down Shift which will enable the smooth option. And then, oh, look at that. How satisfying it is to go over the geometry and smooth
everything a bit, super nice. And as always, if there
is too little geometry you can add more if you like. So now imagine you have
everything retopologized now to wrap it up, you apply
the Shrinkwrap Modifier and you apply the mirror modifier and as final step, make
sure that here at the center all vertices from the mirroring
axis are actually merged because sometimes you
have little holes there. So, and if you wanna add
an extra level of smoothing you can add the smooth modifier here and repeat it a few
times and then apply it. This of course works a bit better if you have everything retopologized and don't have an open mesh over here. Then you can remove the material and in the object tab,
under viewport display you can disable wire and in front. Now let's hide the original creature and here's our pure retopology mesh. Learning these skills is relatively easy mastering them takes time. If you want to dive deeper into retopology and especially
sculpting in Blender check out my comprehensive
sculpting course on ACADEMY.CGBOOST.COM. This is a great way to improve your skills and to support what we do. Thanks for watching, Zach out.
