& Construction
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Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
& Manufacturing
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Professional CAD/CAM tools built on Inventor and AutoCAD
Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
Professional CAD/CAM tools built on Inventor and AutoCAD
Transcript
00:00
Here I've got four 360° revolves from exactly the same curve.
00:05
But if we display the geometry, you can see that I've got some quite different results in terms of the CV layouts and the surface layout.
00:15
And if I display some locators, you'll see that the accuracy is also different, depending on the structure of the geometry.
00:22
So, if we have a look at the settings that we used in this one, we've got Non-Periodic with just one segment.
00:29
And that means we've just got a simple NURBS surface looped around to create an approximately circular shape.
00:36
So, it's very efficient in terms of CVs, but not very accurate in terms of being a circle.
00:41
So here, we've used four segments, and we've also increased it up to 6° so that each segment only has to describe 90° of that circle.
00:53
This one here has been created as a Periodic surface,
00:56
which means that if I pick any of the holes and make any changes to them, they will behave equally as if the revolve is a closed loop.
01:06
And you can see that the accuracy here is reasonable enough for concept modelling.
01:11
Finally, we have a Rational setting in our Construction options, which takes away your option of having Periodic or Non-Periodic.
01:20
And it's built with weighted CVs that give your revolve accuracy, but that make it not very practical for sculpting due to these sharp edges.
01:29
So, the two options I will generally use most are splitting into four segments—or however many segments you want for accuracy—
01:38
or using a Periodic, if I want to later on sculpt the shape and keep it as a coherent loop.
Video transcript
00:00
Here I've got four 360° revolves from exactly the same curve.
00:05
But if we display the geometry, you can see that I've got some quite different results in terms of the CV layouts and the surface layout.
00:15
And if I display some locators, you'll see that the accuracy is also different, depending on the structure of the geometry.
00:22
So, if we have a look at the settings that we used in this one, we've got Non-Periodic with just one segment.
00:29
And that means we've just got a simple NURBS surface looped around to create an approximately circular shape.
00:36
So, it's very efficient in terms of CVs, but not very accurate in terms of being a circle.
00:41
So here, we've used four segments, and we've also increased it up to 6° so that each segment only has to describe 90° of that circle.
00:53
This one here has been created as a Periodic surface,
00:56
which means that if I pick any of the holes and make any changes to them, they will behave equally as if the revolve is a closed loop.
01:06
And you can see that the accuracy here is reasonable enough for concept modelling.
01:11
Finally, we have a Rational setting in our Construction options, which takes away your option of having Periodic or Non-Periodic.
01:20
And it's built with weighted CVs that give your revolve accuracy, but that make it not very practical for sculpting due to these sharp edges.
01:29
So, the two options I will generally use most are splitting into four segments—or however many segments you want for accuracy—
01:38
or using a Periodic, if I want to later on sculpt the shape and keep it as a coherent loop.
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