Blender 2.81 Features | The New Remeshing Tools


Hi Aidy Burrows here and you’re watching
the remeshing tutorial here from the 2.8 update for the hard surface modeling
course in blender as well as the poly build tool which is more of a manual
retopology approach we also have two automatic retopology methods with the
voxel remesh and the quad remesh let’s take a look at those and see what’s on
offer. Voxel remesh is not only available from the object data tab it’s also
available in sculpt mode I’m going to switch over to the sculpting workspace
actually which should put us into sculpt mode automatically and then I’ve got our
sidebar open here with the N key which is this on the side and we can see
there’s actually another remesh section right here which is a
duplication of this information so that’s pretty good for working just in
one large 3d View window so ‘Ctrl + Space’ for me I have it set to that
default giving us as much screen estate as possible or at least closing out the
other windows anyway and in fact the fact that this remesher is available
within the sculpt mode probably helps explain the context the main purpose of
these remesh tools that is to say that it’s generally speaking the remeshers
would be used within a sculpting workflow when evenly distributed
geometry is needed that’s what we’re getting here in contrast to a manual
retopology workflow where we can choose to have different levels of
detail throughout the mesh right now I barely have any geometry here it’s just
six faces to this cube as you can see in the status bar down there so if I was
to try and just sculpt with the clay strips brush for example not a lot
interesting is really going to happen here but if i remesh using our default
size there and then try that again we can see we’re actually starting to get a
little bit of something happening and if we take this detail even lower we’ll get
even more geometry to work with almost like even more pixels to be able to get
a clearer sharper image from sometimes during the sculpting process we might
say grab something and pressing the F key to just scale up our brush there
I’m going to drag this bit out over there like this and then if we just
toggle on our wireframe view here we can see that the resolution of what we have
on our sculpt object is no longer even so if we were to try and start to sculpt
now we’re not really going to get the same kind of consistency and results as
we might do if we were to sculpt over here and that’s not a very intuitive way
to work but the beauty of having these remesh tools is that we can just hit
remesh and now we have that even resolution back again for example in
this scene I’ve just got a simple plane which is subdivided a whole bunch of
times just to create the resolution of vertices for which to paint with in
vertex paint mode and created this really basic picture I’ve actually just
put this decimate modifier on there and as we reduce the ratio meaning the
amount of vertices there are on here you can see our resolution is basically
getting destroyed in some places but it maintains its clarity in others and
it becomes pretty clear when we see the wireframe that an orderly and evenly
distributed amount of geometry is going to be pretty crucial to get that
consistent result this is why I’m sure you’ve grasped at this point that a re
mesher of any kind is pretty useful addition to the sculpting workflow I
just want to draw attention to the fact that it’s only the voxel re mesher that
is available here in sculpt mode on the sidebar but we can still get access to
the quad reflow re mesher from the object data tab so if I go ‘ctrl space’
to minimize the view here and we take a look at the remesh section we can switch
from voxel over to quad initiate the quad reflow remesh here that brings us
this floating panel and let’s just use all the default settings you can see
we’ve got around three and a half thousand faces using this voxel remesh
that we did so I’m gonna just leave that at the default 4000 and then
click OK, allow it to just run the analysis and the algorithms it needs to
be able to retopologize this and it’s given us this kind of result so
we’re still in sculpt mode it’s just we had to come out of full screen mode to
be able to initiate that since it’s not included on this sidebar and also a
quick note it doesn’t look like it’s done quite as good a job as voxel did
on the default settings there so for this round anyway the voxel remesher
wins there are a few other differences between the remeshers so let’s take a
closer look starting with the voxel options put simply the voxel option is a
faster and more basic algorithm quad reflow takes longer and will
try to respect the flow the curvature of the mesh a little more but let’s put the
voxel remesher a little more under the microscope I’m going to come out of
the sculpting workspace pop back over to our default layout and then delete this
cube and add in a new one we currently have a voxel size of 0.1 so if we go to
voxel remesh now and take a look from top orthographic view these gridlines
here that we have are 0.1 units large and so you can see that the re meshing
grid that has been applied to our voxel algorithm here is 0.1 so we can easily
understand this voxel size setting but what might not be immediately apparent
is the kind of direction of the grid might be quite important so for example
let’s add in another cube let’s push that off to the side and then if I was
to rotate so R Z 45 degrees and then keep that 45 degrees rotation and not
actually apply it if we just simply voxel remesh its gonna ignore that
rotation let’s just duplicate that off and then what I’ll do this time is ‘Ctrl A’ and apply that rotation now if I initiate the voxel remesh and we jump
into the top orthographic view you’ll notice the grid that has been applied is
aligned to the world and in this case it hasn’t made as clean a job on the edges
there let’s take this one again and ‘shift D’ to duplicate it and bring it
over on this side and let’s ‘Ctrl A’ and apply the rotation again so if we
were to do the voxel remesh on this we’re gonna see how the voxel remesh is
being challenged there on those edges so i’m going to undo that with ‘Ctrl Z’
switch over to the Quadriflow go to Quadriflow open up the tool and then if
we just click okay let’s see what we get and we can see that the general flow of the
faces has been taken into consideration it’s not quite perfect you see it’s a
little bit on the wonky side but generally speaking the grid that has
been applied the resolution that we’ve been given for this mesh now is mostly
there just to bring these details together let me just create another cube
press G and X to constrain it to that axis bring it over tab into edit mode R
Z 45 to rotate it tab back into object mode this way we don’t have to apply the
rotation let’s switch over to the Quadriflow remesher click our settings and
seeing how we use this as an example let’s just
quickly take a look at preserve sharp click OK and then we should find that
once the algorithm has been finished and the remesh has been applied that its a
much cleaner and almost perfect remesh of this cube actually we take a look in
wireframe will see that this only minor imprecisions happening there so
something we’ve hinted at there with the object rotation would be similar to
the object scale so I’m gonna switch off these cubes and just take a look at this
kitbash item from the hard surface modeling
course and this is a very basic very simple object and we can see it’s got a
scale value of 1 at the moment and if we voxel remesh we can see it’s not doing
a very good job because it’s actually quite small so again if we take a look
from top orthographic view we can see our grid spacing so we really didn’t
have enough resolution for that so if I go ‘Ctrl Z’ and undo it I’ve got two
options at this stage I can scale this up so let’s tab into edit mode, select
everything, ‘S’ and then let’s say ’10’ then tab back into object mode and then
hit voxel remesh again you can see now we’re getting far more details we’re
getting nearly 20,000 faces turning the wireframe off we can see that it’s not
really done a good job for this particular object so we would probably
want to take our resolution down even lower so I’m going to undo that with ‘Ctrl Z’ let’s go 0.01 on here so not only have we scaled this up by 10
times we’ve also reduced our voxel size down by a magnitude of 10 so let’s now hit
the voxel remesh and now we’ve got a far better representation here’s a useful
note to make about the voxel romesher which we can do with this little spot
the difference this one is just the original mesh and this one here is our
remeshed version and just to make it really easy let’s turn on our cavity
shading and shadow I’ll just use the defaults for now, now aside from being
able to determine all the individual or at least the original wireframe, we can
also see that this box area, this little box detail has gone so what I’ll
do is I’ll take this object, tab into edit mode, 3 for face select and then
ctrl L to select everything G and then Z to just lift it up and we’ll see
underneath that it actually doesn’t have an enclosed face there so if I deselect
with ‘Alt A’ that might make it more apparent there
so let’s undo that put it back into its place Z to switch into wireframe, 2 to
get the edge loop right here alt and left click and I’m just gonna press
F to create a face there numerous ways to do that I could have just gone ctrl L
and then shift H to hide everything else and we can clearly see that we’ve got
that extra face at the bottom now so alt H to bring everything back tab into
object mode I’ll create another version with shift D to put on the left side
of it and on this one now we’ll run the same voxel remesh and we’ll notice that
this time the box has been taken into consideration alright so just to drill
the point home and back in the land of the cubes and let’s see if we just add
another one here and then this is just going to be a very simple intersection
just shift D to duplicate and just raise it and have it overlapping by about a
quarter of its volume there nothing too crazy but if we just shift select them
both ctrl J to join them and then press Z to take a look in wireframe mode you
can see that nothing fancy has been going on this is just two intersecting
cubes no interesting boolean operation has taken place or anything but if we
take our voxel size and just make that slightly higher actually just to make
the wireframe really easy to read and then hit voxel remesh might be able to
see it has attempted to create a kind of boolean really I’m going to tab into
edit mode just select with shift G all the faces on this side and then hit H to
hide we can take a little look inside and we can see that no longer are just
simply two cubes overlapping it of course seems a little bit crude because
we’ve set our resolution down so low but if I was to just undo a few steps and take
the resolution down a little bit instead and then re perform the voxel remesh
we can see actually we’ve got quite a tight join there and if we right click
to shade it smooth it might act even as a little welding seam between the two
cubes so the overall lesson here is that
non-water tight meshes are welcome here for the voxel remesh and overlapping
geometry parts of it are going to get thrown away for a kind of continuous
shell that can be seen it won’t really have hidden parts to deviate from the
land of cubes into the exotic land of the plane let’s just take a look at this
one and then I’m going to voxel remesh this
now it might look like everything worked there which might be surprising because
a single plane isn’t really a watertight mesh or anything but we can see that
with our backface culling on actually you can still see both sides and if I
tab into edit mode again select a face do that same trick shift G coplanar
and G and then Z and lift that up we can see the additional trouble that we might
get into with geometry that isn’t water tight like a cube as we saw in the Kitbash
example where the box that we had here wasn’t coming along for the ride
since it had its bottom face missing despite it being overlapping with the
rest of the mesh here I’ve got a pretty basic object I just removed the
wireframe for a second you can see that it’s all hard shading let’s stick a
bevel modifier on this set it to angle take another look at the wireframe
actually and then increase that there if we were to come over to our remesh now
just note that it isn’t going to take this modifier into account
so if we voxel remesh you can see it looks completely different afterwards
let’s undo that with ctrl Z first we would need to apply our modifiers we can do that a number of ways we could just hit apply there or we could come to our
object menu and convert to mesh with that done now when we come to our voxel
remesh it’s going to try and incorporate more of that beveled shape there since
we locked it in we baked it in again I’ll undo that though a couple of times
so that we can get our bevel modifier back and then I’m just going to remove
it and then I just wanted to make a little bit more of a note on these edges
that I’ve got toggle the wireframe off again and what I could do is hit shade
smooth come over to here and with our normals hit Autosmooth and now it looks
like there’s a nice smooth curvature this is just a trick of the light the
actual polygons are quite noticeable if we were to take a look from the front
orthographic for example we can clearly see the stepping happening there and
when we’re going to remesh that stepping is going to become more and more
apparent it’s kind of like if we were to 3d print this out again in the real
world we wouldn’t have this trick of the light
it would look low poly in the real world so if I just set our resolution down a
little bit lower and go to voxel remesh we can see that low polygonal structure
much more noticeable and I guess if this was a real 3d object
you’d probably just try and polish that out with some good old-fashioned elbow
grease but for now we can kind of use some errr blender grease
if the metaphor carries and just make sure to use way more polygons basically
to try and get the job done hopefully now when we remesh it’s not quite as
apparent and I think we can just about get away with that one last thing
concerning watertight meshes using the voxel remesher to demonstrate I’ve got
this other kitbash item I’ve just colored it a little bit blue and then
set our color here in the viewport to object so let’s come over to the object
data tab and get ready to give this a voxel remesh first of all though I’ve
scaled it right up so I’m going to apply the scale and then let’s see what
happens if we just do it right now all right so we know this isn’t working
quite right and part of the reason will be because it’s definitely not
watertight but it’s not just this obvious area here there’s actually
another less obvious area right here so I just wanted to discuss a quick way to
find those areas those potentially problematic areas I’m going to switch to
edge select mode here and then select all by trait, non-manifold edges and let’s
use Z to take a look at our wireframe here that’s a problem area we’ve got
that area that we’ve already looked up and also we’ve got the bottom of these
kind of bolts and nuts that we’ve got so all I’m going to need to do here is just
press F and that should just close everything off all in one go just to
make this a little bit neater here though I’m going to switch to 3 for face
select mode and then just extrude that out with E and maybe I to inset that
slightly maybe give that an extra loop just there actually and with that done
let’s see how the voxel remesh does alright so it’s a little low resolution
but we’ve definitely maintained the majority of its shape so I’m going to
undo that with Ctrl Z let’s take that down to 0.01 and try it out again
and that looks way cleaner now the only issue that we’re getting as indicated
in the previous example is just the low poly nature of the object starts to
become a little bit more apparent here I’ve got that same object and i’ve
remeshed it in two slightly different ways I’ve set the voxel size down to 0.05 and
on this one we don’t have the fixed poles options selected
and on this one we do so let’s just take a quick look at the results the
major difference between the two is on this one we barely have any of these
diamond junctions and if we look on here we’ve got tons over on this area and there are several dotted through and across the top as well whereas on this mesh its
tried to be a little bit more reserved when it comes to placing poles
everywhere hence the fix poles take a look at the preserve volume option here
I’ve got three separate objects each object contains a cylinder and the cube
this is the input mesh this is the one with the preserved volume checkbox on
and this one is the one without now i’ve give them slightly different colors so we’re
looking at material colors on here now the cubes have got a gray and the
cylinders have got a darker color and you can see on this one which isn’t
preserving the volume the cylinder especially has kind of shrunk in a
little bit especially on the edges it’s revealing more of the cube at the back
there they’re both pretty much the same size this one is 4.84
meters wide or deep if we’re looking at it from this angle but these two are the
same but generally speaking you can see the shapes are holding a little bit
better when the preserve volume is checked that goes for the cube as well
you can see that here the cube is being rounded out a little bit more as
compared to this one which is preserving the volume this generally gets more and
more extreme dependent on the voxel size but in general it helps to have a more
accurate result so leaving this on is a good idea just to drill the point even
further and actually make a new point as well let’s duplicate this non preserved
volume remesh and let’s do that again just remesh again and we can see that it
kind of contracted even more so I’m just going to undo that and this time
preserve the volume and do that again and we can see it did a much better job
but instead I’m going to undo that and also show the smooth normals option at
the same time and this is a really simple checkbox basically just going to
smooth the normals for us so as we do that now and I take off the wireframe we
can see while these remesh examples are still flat shaded this one is now smooth
just note it isn’t set to auto smooth in our normals there this is just
right-clicking and shading smooth essentially let’s take another
duplication of these simple primitives that we’ve got and then take a look at
this other option here preserve paint mask now think this is probably going
to get renamed at at some point since this is a little bit misleading as it’s
not talking about anything to do with our texture painting coming over to our
tools tab and adding some simple UVs and adding in a base color just scrolling
down a little bit you can see that within here we do actually have a mask
or a stencil option within our painting but instead of that it’s actually
referring to the sculpt mode so when we come over to the sculpt mode I’m gonna
open out our tools so we can read them here and if we scroll down a little bit
you’ll see that we’ve got one called mask and as we take this and start to
paint we’re painting a mask meaning this area isn’t going to be affected when we
go to do some sculpting it might not be as well contrasty as it could be there
so let’s take this black material here and make it much lighter so that we can
make out our mask even better and now if we come over to the remesh settings and
enable the preserved paint mask which probably should say sculpt mask what
I’ll do is take this voxel size down a little bit so that we can see more of a
change when we come to remesh then we’ll hit the voxel remesh button and then we
can see after it’s finished remeshing we still have our sculpt mask preserved
I’m gonna switch off this kitbash collection and ride back into cube town
and let’s go and add in a fresh cube and take a look at our remesh settings all I
want to demonstrate on this is the adaptivity so the first thing to note on
this is that as soon as we raise this up anything past zero it’s essentially
going to switch our fix poles off perhaps that should be grayed out
actually when this value is above zero just to make that clear so what this adaptivity is trying to do is just preserve detail where it needs it so on
the corners in this case and in the middle of the flat faces it’s gonna try
and reduce or decimate some of those polygons that aren’t really contributing
to the shape therefore giving us a lower poly count overall so let’s just take
this with 0 just to remind ourselves what we get and let’s toggle a wireframe
on so this is giving us around two and a half thousand faces and it’s
soon as we try and add some adaptivity into this and try again we can see in
the center of the faces we’ve barely got any additional polygons there and our poly
count for this cube now is under a thousand so four times less I’m gonna
drop this even lower to 0.01 and drop this higher 0.2
and see what we get and now we’ve got quite a lot of geometry right where the
faces are turning corners let’s try and take this even higher like 0.5
and we’ll do another remesh basically the higher this value goes the
lower the poly count should be and a quick note we’re locked out at a value of
about one meters lower details for example 0.01 in this case means that
basically more details going to be kept and therefore a higher poly count with
had surface models I can’t say I’ve had a lot of usable results with this but
it’s definitely worth knowing that it’s there probably a little bit more
suitable for applying that with more organic shapes let’s take another look
at this particular object again let’s make it more readable by turning on our
shadow and cavity options in the viewport and I’m going to toggle the
wireframe on this so let’s just duplicate this out with shift D and take
another look at this one do a simple fix poles preserve volume which should be
its default and to preserve some of the more smaller details I’m going to take
the voxel size down to 0.01 and then we’ll just hit the voxel remesh button
keep an eye on the box we can see there’s a little bit of an issue there
let’s come over to this one as we remember we actually capped the under
floor of this box to make it work in voxel mode let’s take a look at quad
mode instead and go quad reflow remesh and use the default settings and click
OK now it doesn’t look too great at the
moment but it has preserved the box something else to bear in mind we take a
look around here we can see that this cylindrical part here seems to be
attaching to the main base of the object which isn’t normally which it actually
shouldn’t be and if we take a look at this version you can see that the Quadriflow remesher it hasn’t struggled with separating that geometry there plus an
extra bonus is that it’s thrown in the Box for us so the non manifold geometry
and intersecting and overlapping parts are kind of preserved here so we take a look
at this section and just lift it up have a look underneath and you see it still
has a face missing at the bottom there so while a Quadriflow can be way way
slower like 20 times slower to get the same amount of polygons it can actually
yield better results as this is going to allow us to set a polygon target as we
can see here and generally does a better job at following the geometry it’s gonna
accept planes and non watertight meshes let’s just try that out with a mesh
plane here if I tab into edit mode shift D to duplicate it let’s rotate
that on the z-axis just to give it a little challenge and then take this
object let’s go over to the quadriflow and then let’s just choose default
settings and click OK and watch it work it’s magic take a look at the wireframe
on this and that’s done a good job of figuring out the orientation of the
planes there plus it hasn’t created any kind of additional geometry underneath
like attempting to convert these planes into a kind of squashed down boxes or
anything let’s put the settings for the Quadriflow remesh under the microscope
a little bit so we’ve got this use paint symmetry again that isn’t texture
painting or vertex painting or anything like this
we even have mesh symmetry that you can see up at the top there when we tab into
edit mode but you’ll notice that both remeshers here are greyed out while in edit
mode so we can’t be an edit mode to initiate these the symmetry that is
referring to is going to be found in sculpt mode which again is basically in
the same kind of place there so at the moment here I’m set to the x-axis so
it’s going to copy what’s on the left side here and throw it over onto the
right so essentially what we’re saying here is that this should be actually a
symmetrical mesh and if we do happen to be working on a
symmetrical mesh which is quite common while sculpting we’re basically saying
to the algorithm you only need to do half a job and then once you’ve done
half of it just copy that to the other side so it’s a way to speed up the
process here so if we click OK and see what kind of result we get on this mesh
we can see we are now left with a symmetrical mesh along the x-axis our next
setting is the preserve sharp option here’s a simple input mesh the super basic cube
and over here we have the results of preserving sharp and then on this one
I’ve turned that off and as you can see if we take the wireframe off we’re
having quite a bit of an issue around some of the sharper areas there so
clearly with a more hard surface object that preserving the sharp is going to be
the way to go there taking a look at the preserve mesh boundary option here
this is the input mesh, a simple cylinder with just a hole cut out of the side
this is the result of preserving the mesh boundary this is the result without
you can see the result of the geometry created around this mesh boundary is
pretty poor on that version especially when compared to this version it’s not
perfect but it’s definitely way better than this version let’s take a look at
the next setting using this as an input example this is our first result now
what’s happened here is we’ve got preserve sharp set, we’re preserving the
mesh boundary, use mesh curvature was also enabled for this one and if we take
a look around the handles area of this we can see that the flow of the
polygons are turning a corner there which is looking pretty good and also on
this object this didn’t have the use mesh curvature setting enabled and we
can see that it’s not really turned quite as nicely on the corners and
especially here at the back has been particularly troublesome compared to
this one which was following the mesh curvature more closely the other two
settings this preserve paint mask is talking about the sculpting mask again
as we’ve already discussed with the voxel remesher and that would go for the
smooth normals as well that’s going to give us the same results as before the
only other thing to discuss is that by default we’re set to faces so we can set
the amount of faces that we have as a target that we want the remesher to
reach we also have a ratio, a ratio of 1 is going to use the same amount of faces
that it already has and 0.5 would be half of the amount and 2 would be twice
the amount and as a mode we also have the edge length option which is the
option both of these objects used with a value set to 0.1 which is able to
predict the amount of faces that it’s going to use so the higher we make our
edges the less faces are going to be able to be produced and obviously it’s
going to look way more low resolution and then finally we have our seed so if
we feel a result is very very close but not quite there we can always try a
different seed and see if it nails it that time so that’s what version 2.81
has brought us in the remesh Department but it probably would be a disservice to
the subject if we were not to mention that we’ve had a remesher modifier for
a while which is what we have here we can find that easily enough right here
under remesh there’s a few basic modes there’s the block’s mode which is more
of an effect than anything but it’s a very cool effect we have the smooth
algorithm which is kind of rounding out corners and then we have the sharp
option which is probably better for more hard surface things preserving those
sharp corners and we have the octree depth and the scale to basically
determine the resolution and fine-tune it and we can decide whether to have it
smooth shading or not I think it’s also worth remembering that with the modifier
it allows us to be non-destructive and it’s actually very easy to animate finally to
round things off let’s take a look at some other remeshers available probably one
of the current best options out there which is actually available as a paid addon
within blender is Exoside’s Quad Remesher they have loads of examples and
further details on the site if a remesher is something you really need
for your professional work and the blender default options aren’t cutting it
then definitely worth a look into this over on the blender market there are
some further options such as Dynremesh and Atoflow from AlbertoFX this has a
lot of interesting useful and easily controlled features another on the
blender market is Tesselater from flow tools interestingly the add-on uses a
particle system that can be guided by the grease pencil
to inform the end results a few free options include IGL, MMG and Meshlab it’s
possible to get a quick feel of those and how a couple of those compare on
this demo page for the Quadriflow remesher you can choose an input mesh and
then specify the algorithms to see how the results differ so that should wrap
us up for what 2.81 brought us in regards to remeshing this is Aidy
Burrows and you’ve been watching the 2.8 update for the hard
surface modeling course in blender

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