We can just tell Blender "hey Blender, if the angle between two faces is below this value, then don't smooth over that edge." So to avoid those weird shadow issues, we need to tell Blender “hey Blender, if the angle between two faces is 90 degrees or higher, smooth everything (bad shadow in this case!).
Bevel Limit Methods - Angle
In the above images, the top one has every edge chamfered, and the bottom one only chamfers the top edge. The "angle" boundary method in the chamfer modifier works exactly like the auto-smooth angles: it chamfers edges based on angles.
Bevel Limit Methods - Weight
This is useful because with the Corner Constraint method, corners will sometimes capture areas you don't want to capture to tilt another portion of the object. Corner limit method is not as versatile, but it is immediate (you don't have to make any manual selections).
Booleans
I probably use difference Booleans 70% of the time, unions 29% of the time, and crosses 1% of the time.
Normals – what are they?
The reason the shading gets bad on bevels is because a bevel has multiple angular normal lines. What we really want is for those normal lines in the picture above to be straight up and down (top) and straight side to side (right).
Booleans (continued)
There is a very simple rule when it comes to Booleans: There must always be 2 connection points in the Boolean. Notice how after the chamfer is increased too much, it "runs into" that connection point. The taper would have a lot more buffer if it had more time to taper off before running into that connection point.
Notice how we can now bevel as much as we want without running into the connection point. As a side note, by default Blender will not allow you to bevel past the point where the chamfer "runs into" the connection point. You can disable this by disabling the "Clamp Overlap" option in the Geometry drop-down menu in the Bevel modifier.
Sometimes in more complex meshes the overlaps can occur almost immediately, causing the clamp overlap option to kick in before the chamfer can even be performed.
Booleans (curved surfaces)
Unlike with flat surfaces, we can't just slap a weighted normal modifier on a curved surface and hope the shadow clears up. Just keep the things mentioned above in mind and you won't be fine using ngons and Booleans in your workflow. The trick is to get the Boolean so tightly isolated that the shadow artifacts are barely noticeable, if at all.
This means that the sun protection can only extend to those two horizontal loops, otherwise the sun protection is perfect because they are all quads. All ngons are shown in red here, which is exactly the area where the bad shading occurs. Although the shadow looks good, we have these little black glasses around the Boolean cut.
On the downside, you'll probably have more objects to clear as a result of the closer geometry.
Ngons vs. Quads – The REAL answer
Meshes constructed with ngons are much faster to make and much easier to edit compared to all quads
Because of this, Ngons provide for an iterative design workflow, when the artist can try out different concepts and many times in a non-destructive
Ngon workflows are also better at creating parts for 3D printing because of modeling speed and the use of Booleans and are easily tested for non-
As a result, Ngons allow for an iterative design workflow, when the artist can try out different concepts and many times in a non-destructive way. Point #2 in Chipp's discussion brings us to a new topic, the topic of non-destructive vs.
Non-Destructive vs. Destructive Modeling
Now what if I want to move the clip in the middle somewhere else, maybe a little closer to a corner. No seriously, you'll feel like a pro if you know the answer instead of giving it to you, so please think about the answer - I'll tell you on the next page. So, the answer here—and we've already hinted at it—is that if we want to move that clip into the top, all we have to do is move the cutter object.
There is no need to manually select the entire geo, because we are working non-destructively: the Boolean is not applied, so it is still live for adjustment in the viewport. This is the power of a non-destructive workflow, and we often use it when modeling hard surfaces. Of course, there will be times when you need to apply your Booleans because there is simply no other solution.
You may need to clean up the geometry, apply skew weights manually, or simply use them because too many booleans can hurt performance.
Boolean Cleanup Strategies
If they're super small and you're doing concept renders, sometimes they're unnoticeable, so you can probably leave the little ones alone, but try not to make a habit of it. Let me stop you in your tracks - go to this link, right now, and grab a copy of our Topology Handbook for Blender - it's free and is literally what this section is about, but it's all videos. Seriously, if you don't grab that copy, it's like lighting your rent money on fire;.
After grabbing that "textbook" (actually a series of videos), you can either watch those videos and then read this section or complete this section first. You might have two nearby vertices here and there, which you can either move away like before, or in the following case simply merge. You can merge with the auto merge tool, or simply select both vertices and press the 'M' key.
There is no way I can explain the intuition through text - you have to watch how we work.
Multi-Level Bevels
So what happens is that since Blender has already executed the Boolean command, and the bevel comes after it, the bevel is applied to the entire mesh. Note that the Boolean cut has no chamfers around the edges, because the chamfer was already completed before the cut was applied. I made the bevel a little higher to exaggerate the effect, but this is exactly what happens.
If we set the second chamfer to a higher angle value, it will not capture the original chamfer and should only affect the Boolean cut. It really just comes down to the geometric angles between two edges and controlling those values correctly when running multiple chamfers. Repeating the last example, I could simply add a bevel weight to the edges of the interior cuts and an additional bevel modifier set to angle.
Any skew that you run skew weight on means you have to use a boolean to manually select those edges.
Dicing Booleans
You might think, why don't we just run some loops on the base cylinder. Don't worry about that though, I'll show you the correct way to dice the Boolean area instead. So essentially you just go into edit mode for the cutter and press 'CTRL+R' to add some loop cuts and scroll up to increase the number.
You may want to scale the cutter down and make it just large enough to only fit the area you want to cut. The reason is that if it's scaled beyond the range you need, you'll just spend more time scrolling the scroll wheel and adding loop cuts to fit. Whenever you run loop cuts on a cutter object, all the geometry of the cutter will be transferred to the base mesh.
In conclusion, if you have an odd cut as shown, you may need to cut the cutting object.
Subd with Booleans
Let's assume that this was our final form and we were ready to start slicing and running Booleans. It's important not to even think about the subd at this point - it's been and gone since we applied it. This looks scary because it's organic and polished now, but the same methods presented in this book apply when you use Bools on this surface.
Subsurf is no longer actively running since we applied it, so this boolean is not affected by it. Of course, since the geometry is so dense as a result of the subdivision surface modifier, slanted overlaps will occur almost immediately. You can easily use the techniques taught in this book to fix them (apply Booleans and start merging and sliding the vertices until it's clean).
When people say "never use subs with boolean values", they're only telling half the truth.
Hard Ops/Boxcutter
This is much more efficient than adding a cube, scaling it, positioning it, performing a boolean modifier, and having to go back and forth with this. It is obviously much more complex and it would be impossible to teach the whole addon in this book. It looks simple, and it really is – it just takes a little getting used to.
You do it all with one click and it's completely customizable to what you need. Check out Ryuu's Hard Ops tutorial series again if you want to learn from start to finish. This is because these tools are meant to help you model and speed up your workflow, but if you run into problems and don't know how to solve them because you never learned the default Blender workflow, things will get messy and you'll get lost , without knowing how to fix things.
Without contributors, Blender wouldn't be where it is today (plus a kickback from every sale will generally support the Blender Foundation!).
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Conclusion