In this chapter I'll introduce you to the guide mesh technique, 2
an extremely useful set of techniques for hard surface modeling. 3
I've been working on these techniques for a while and 4
there have been some major updates since my last course. 5
If you've seen my past training, 6
I think you're gonna be pretty happy that adding thickness 7
to panels is now way simpler and totally reliable. 8
So even if you've seen my training before, it's very 9
important to watch this chapter again to see what's changed. 10
But I do go over this stuff in the course as well. 11
For this chapter I just wanted to get all the information on the technique in one place 12
for you to use as a primer for the course and also a reference guide for your own projects. 13
There's also a PDF in the course files that has all of the main 14
technique information so you can use that as a reference too. 15
First up I'll be going over the theory of how it all works and then I'll get 16
into the rules of using it because there are certain ways things need to be done. 17
So to start off, in this scene here I have two hard surface panels that 18
have a separation going down the middle and also this cutout right here. 19
And when I rotate the view to check out the reflections you 20
can see problems that are probably all too familiar to you. 21
One of them being that the reflections are not 22
passing seamlessly between the panels in the middle. 23
And another one, when I cut out this hole here, I had 24
to add extra edge loops to sharpen up all the corners. 25
And of course this extra geometry creates all of these creases that you see in the reflections. 26
It's a mess and all we wanted to do is have two separate panels 27
with a small separation in the middle and a rectangle cutout. 28
But that separation and that extra geometry messes everything up. 29
Now a common way to avoid problems like this is to have 30
more geometry before making the separations and cutouts. 31
Like if I go into edit mode, you can see things are fairly low poly. 32
But if before I made the separation and the cutout, 33
if I applied the subsurf modifier at level 1 or 2 34
this would give the curvature more structure by adding more real geometry to it. 35
Then making the cutouts and the separations wouldn't have such a big impact. 36
But although applying a subsurf modifier gives you 37
more geometry to work with for cutting out details 38
you end up with a lot more geometry. So this makes it less efficient and harder to edit. 39
But here's the thing. We already have that subsurf geometry. It's right here. 40
But because this is generated by the subsurf modifier, we can't work with this directly. 41
But what we can do is shrinkwrap it. 42
So in order to fix this surface and restore its perfect round curvature 43
we simply need to shrinkwrap this on top of a version of it that has no holes or separations 44
which I already have in this collection right here. 45
This is literally just the perfect curvature without the extra cutouts and separation. 46
And I call this a guide mesh. 47
And what we're going to do is shrinkwrap all of this subsurf geometry onto this perfect curvature. 48
And to do that, we simply select the mesh that we're shrinkwrapping 49
which I'll refer to as the final mesh in this course. 50
And I'll go over to the modifiers, add in a shrinkwrap modifier 51
and let's target the guide mesh. 52
And there we go. 53
No more creasing, no more flat spots. 54
And we have a perfect seamless reflection passing between the panels. 55
Everything is completely perfect. 56
Here's what it looked like without shrinkwrapping and with shrinkwrapping. 57
Awesome. 58
And the cool thing is you can be pretty sloppy with topology too. 59
For example, if I were to select this quad here and triangulate it 60
normally triangles on a curved surface would impact the quality of it. 61
But not with this technique. With this method, no problems. 62
Because all that matters with this method 63
is that you have a good enough amount of subsurf geometry 64
to shrinkwrap onto the perfect guide mesh surface. 65
As long as you have a good number of faces and these 66
faces are somewhat consistent in size and spacing 67
then everything should shrinkwrap onto the guide mesh really well. 68
And even if you mess the topology up pretty bad, 69
like I'll move a couple of vertices around randomly 70
you can see everything is shrinkwrapping perfectly still. 71
And that's because the subsurf topology is still somewhat consistent and spaced out 72
so this is still shrinkwrapping really well. 73
You still want to be careful though to get the best results. 74
This method can't save you if you mess things up too much. 75
But this actually does a great job with a more reasonable amount of bad topology. 76
And that's important because if you need to make cutouts 77
for things like headlights or gas caps or whatever 78
then that topology is going to get a little messy. 79
But this method is going to save us a lot of trouble with that 80
and it's going to make the whole process a lot more carefree and fun. 81
All right, now let me go back to a point before I 82
made these changes to the model and messed it up. 83
All right, there we go. Back to the perfect topology and perfect shrinkwrapping. 84
Now I just want to mention that because we're shrinkwrapping subsurf geometry, 85
which is geometry we don't have direct control over, 86
it can create some complications, so there are specific 87
ways that we need to do things in order to avoid trouble. 88
So that's what we'll be exploring in the rest of this chapter. 89
So rule number one. 90
Shrink wrap modifiers go below the subsurf modifier. 91
In order to be able to shrinkwrap subsurf geometry onto a guide mesh, 92
the subsurf geometry needs to be generated first. 93
So the shrinkwrap modifier goes below the subsurf modifier. 94
That way the extra geometry can be used for shrinkwrapping 95
and that will give us the smoothest results. 96
Rule number two. 97
The subsurf render levels of the guide mesh need to be 98
two levels higher than the final mesh's render levels. 99
Right now the subsurf levels of our final mesh are set to two 100
which is typically what I aim to use when modeling. 101
If I go over to the other collection and select our guide mesh, 102
you can see our guide mesh's subsurf levels are set to four, 103
which is going to give us a whole lot of extra geometry, 104
and that's going to be essential to get the smoothest shrinkwrapping results. 105
If for example we set the guide mesh down to a subsurf level of one, 106
well then these faces here are going to be much larger than our final mesh's faces. 107
So if we go back to the first collection and we check out our final mesh here, 108
you can see that all of these faces are a lot smaller than the faces on the guide mesh now. 109
And that's going to result in a very faceted look, 110
because several of these smaller faces 111
are being shrinkwrapped onto one larger flat face on the guide mesh. 112
And that's going to give us a lot of flat spots. 113
So that's why we keep the subsurf levels on the guide mesh two levels higher, 114
so the surface is guaranteed to be smoother. 115
So let me set this back up to 4, two levels higher than the final mesh. 116
And that'll bring back our perfect shrinkwrapping. 117
Now you can actually lower the viewport levels to get faster previewing in the viewport, 118
but just make sure that your render levels are set to 119
what you need for both the final mesh and the guide mesh 120
so that things look right at render time. 121
And now one quick final note on the final mesh. 122
I would typically only use two subsurf levels maximum when shrinkwrapping, 123
that way we're not shrinkwrapping too much geometry which can slow things down a lot. 124
So I would keep this subsurf modifier at two maximum, but if I then needed extra subsurfing, 125
what I can do is add an extra subsurf modifier at the bottom of the stack for more smoothing. 126
Rule number three. 127
Keep your final mesh's subsurf topology clean and consistent for the best results. 128
Although you can be pretty messy and carefree with your final mesh, like we saw before, 129
and you'll still get good shrinkwrap results, 130
avoid having areas where faces are really congested. 131
For example, with this subsurf geometry here, 132
you can see there's no major deviations in the topology. 133
All the faces are somewhat consistently scaled. 134
There's no giant faces, no super tiny faces, and no extreme congestion anywhere. 135
And that's why we're getting perfect results. 136
However, if I go into edit mode and I add a bunch of loop cuts through here, for example, 137
you can see that this congestion is creating some issues. 138
And that's because all of these teeny tiny faces 139
are shrinkwrapping onto larger faces on the guide mesh, 140
causing these flat spots. 141
So let me undo all that. 142
And we get our perfect reflections back. 143
All right, so we're done with this. 144
Now let me head over to another collection where I have a different mesh. 145
So now we're up to rule number four. 146
Make sure to have control loops around all cutouts and around all borders of the panel. 147
This extra geometry ensures cleaner shrinkwrapping. 148
In this example, I have a panel here with a triangle cutout 149
that's also shrinkwrapped onto the guide mesh from before. 150
So the surface looks perfect. Well, almost perfect. 151
Let me zoom in to the top of the triangle cutout. 152
And you can see we have some issues around the point there. 153
And if I Tab into edit mode, you can see there's no extra control loop around the cutout. 154
And you can see without that extra control loop, 155
there's less geometry around the cutout to shrinkwrap. 156
And this is what's causing those artifacts we saw. 157
But if I were to add a control loop real fast 158
I can do that by selecting the cutout, facing it, and then insetting it. 159
And I'll erase the face there. 160
And that will give us a control loop around the cutout. 161
With that extra geometry, you can see the shrinkwrapping is now perfect. 162
So that extra edge loop gave us the extra subsurf geometry we need 163
for cleaner shrinkwrapping. 164
And you should add these extra control loops around all the rims of your panels as well 165
for better shrinkwrapping there too. 166
And you can actually add control loops for both cutouts and rims at the same time 167
by following the steps in the next rule about adding thickness for panels. 168
So let me delete the inner edge loop here real quick. 169
So this no longer has a control loop. 170
And we'll add that back in when we add thickness next. 171
Rule number five, adding thickness. 172
Adding thickness to a shrinkwrapped panel and rounding off the edges 173
so they're not flat is a little tricky. 174
With simpler panels, you can just add solidify and then a bevel modifier. 175
But most of the time, this doesn't work well enough. 176
And the bevel results can be inconsistent from one panel to the next. 177
But I've come up with a technique that gives us perfectly consistent beveled rims 178
for every panel, and it's easy. 179
And this works best for thinner panels like car panels. 180
So first I'll go into edit mode, press A to select all the vertices 181
and then I'll use the inset tool by pressing I. 182
And then I'll type in 0.004 to inset everything that amount. 183
And as you can see, this created extra control loops 184
around all the rims and around the cutout here as well. 185
And most importantly, when you use the inset tool to create control loops 186
it makes the control loops consistently spaced away from the middle. 187
Like all of these edges are consistently spaced from the edges here, all the way around. 188
This added consistency will help the bevel modifier results be completely consistent too. 189
And with this technique, the more we inset things 190
the more rounded off we can make the rims when we go to solidify them. 191
But insetting things too much can create some problems, like overlapping geometry. 192
And after testing things out, I found that insetting by 0.004 193
is a good amount that still gives us a rim that's rounded enough in the end. 194
And next, this is the part where I sharpen any corners that I want to be sharper. 195
For example, down here we have a very rounded corner. 196
If I wanted this to be sharper, I can use the knife tool at the corner here. 197
So I'll press the K key, click there, and on that vertex, and over here 198
and then press Enter. 199
And that will give me a nice sharp corner down there. 200
And I do usually wait until after I inset the panel to create sharper corners. 201
If I had sharpened the corners first, I would 202
have needed to add more geometry to sharpen them. 203
And this could have complicated the inset process. 204
And now everything else about adding thickness is just adding modifiers in. 205
So let me Tab out. 206
And now the next step is to add a solidify modifier. 207
So let me minimize these, and I'll add in a solidify modifier. 208
And I'll set the thickness here to 0.002, which is 2mm. 209
And let me get an angled view of one of the corners here. 210
All right, so the solidify modifier gave us some thickness, but it also gave us a flat rim. 211
So now we'll need to round this off. 212
And we'll do that with a bevel modifier. 213
But we want to make sure to only bevel the edges around the rim and around the cutouts. 214
So let's add bevel weight to them so we can target just those edges for beveling. 215
So let me go into edit mode, and I'll select all the edges on the outside of the rim 216
as well as the edges on the inside of the cutout. 217
And then I'll press the N key for the right-side toolbar 218
and over in the item tab, under edges data, I'll increase the mean bevel weight here up to 1. 219
All right, now let me Tab out, and I'll get a view of that corner again, up close. 220
And now let me add in a bevel modifier. 221
So I'll minimize, solidify, add in a bevel modifier 222
and then let's set the limit method here to weight 223
so that we just bevel the edges that we added weight to. 224
Now for the width type here, although having this set 225
to offset can give us good results on simpler panels 226
it doesn't give us as consistent results as other types. 227
And the clamp overlap option in the bevel modifier 228
definitely causes more problems with this type too. 229
So let's set this to percent. 230
And let's increase the width percent up to 100 231
and we'll increase segments up to 2 for a higher resolution bevel. 232
Now the percent width type here will set the bevel width 233
to a percent of the distance to the surrounding edges, 234
and because we created that consistently spaced out control loop around all the edges 235
that means the bevel width will now be consistent all around the rim too. 236
So this is the best and most consistent setup for this. 237
Other setups might give you a bevel width that changes 238
at different parts of the rim, but this is consistent. 239
Now there's just one final issue, 240
and let me switch over to the silver matcap so we can see it more clearly. 241
You can see by increasing the bevel to its maximum amount, 242
it caused a little issue in the middle of the rim here. 243
And this is because if I decrease the width percent here 244
and then I increase it again, you can see those two 245
edges in the middle come together and overlap each other. 246
And these overlapping edges are creating the shading problem here. 247
But the problem is, if we reduce the bevel to get rid of that shading problem 248
well then the rims aren't as rounded as they could be. 249
So it's best to keep this at maximum. 250
And then to deal with the overlapping geometry in the middle 251
let's simply add in a weld modifier which will merge any overlapping vertices. 252
So let me minimize bevel, click on add modifier, and I'll add in the weld modifier. 253
This is merging too many vertices though, and things are getting a little bit weird. 254
We just want to merge any vertices that are perfectly overlapping each other. 255
So let's change the distance amount here to 0.0001. 256
So I just added in an extra 0. 257
And there we go. 258
And that does it. 259
Our panel is complete. 260
It's shrinkwrapped and perfect. 261
And it has procedural thickness with a nice rounded off rim. 262
This was a huge, huge, huge update to how I used to do things. 263
And it's all thanks to the addition of the weld 264
modifier here in the more recent versions of Blender. 265
And that's all there is to it. 266
So you inset your panels for control loops 267
sharpen the corners, solidify, bevel, and weld. 268
And you get thick panels with a rounded edge that will be perfectly consistent on this panel 269
and every other panel of your car. 270
All right, and that does it for this chapter. 271
There's so, so much more that can be done with these techniques. 272
And we're going to get into all of that throughout the course 273
as we dive into using these techniques in real circumstances. 274
So I'll see you in the next chapter.