Final scene

Since it that time in the year again, some of you might find it useful to learn how to create few Christmas decorations for your tree visualisations

Introduction

Well, basically what we will do here is use solids for basic shapes and cut them how we like it.Simple, eh?

Step 1

In this step we will be creating the simplest decoration.

First Decoration

Go ahead, and create a sphere using Sphere command. Center it in the origin (0,0) and use 10 units as radius. To make this even simpler, you can set your Grid options like I have them. Just run Grid command, and where it says Extents click on it and input 10. That way you will have 10 units in your grid in every direction in the viewport which was active when you run the command. To apply this setting to all viewports, just use ApplyTo setting in Grid command. Click on it so it toggles from ActiveViewport to AllViewports. Now, simply using Snap option in your status bar we will start creating this Sphere.

Image 1

Once you got your Sphere, create another one, using 7 units as radius and position its center on 8,0. That is, 8 on the x axis, and 0 on the y axis.

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Now, using BooleanDifference make a hole in the bigger Sphere.

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We need to fillet the edges of this sphere. Using FilletEdge command fillet the edge with 0.2 as radius.

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Create a Circle from Top viewport with 5.5 as radius.

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We will Project this Circle onto the Sphere. We need to do this from Top viewport. So make sure it is active, and run the Project command to do the projection of the Circle on the Sphere. You will get 3 projected curves, and we only need the top one, so you can delete other two:

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Using Split or Trim command, we need to trim the upper part of the Sphere, with projected circle.

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Next thing we need is another Circle. This time create a Circle with 1.5 units as radius. Create it from top viewport in the origin (0,0). Then you will need to move it up (from either front or right viewport) with Move command by 17 units.

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Now, using ExtrudeCrv extrude this circle up by 1 unit. Make sure you don’t have Cap set to Yes, or BothSides set to Yes. Those two options need to be set to No.

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Ok, once you’ve done this, you need to make a surface with smooth transition from the sphere to the extruded circle. You will use BlendSrf command to do just that. As for the BlendSrf options, just leave it at default settings. Meaning AutoChain set to No, and for the Blend Bulge leave it as well at default settings, which are 1,1 and all other options unchecked.

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Next we will create a cap and a little wire to hang our decoration somewhere. So, using OffsetSrf offset the little cylinder surface outwards by 0.1 units.

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Now, using ExtendSrf command we will extend the upper edge of the offset surface up by 0.1

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Using Cap command we will close this surface into solid.

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Create another Circle, from Top viewport and use 0.5 units as radius. You should get your circle like on the image below:

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Now, using ExtrudeCrv command set the Cap setting to Yes, and extrude it up by 20 units, just so it goes through the cap:

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Using BooleanDifference command make a hole with this cylinder in the cap:

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Using FilletEdge fillet the edges of the tip with 0.1 as radius:

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Create another Circle with 2 units as radius, and position it like on the image below. Just make sure you create your circle from Front viewport. You can start Circle command, input in the command line when it asks you for the center 0,20 for the center, and then just 2 for the radius. You should get exactly the curve like on the image:

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We need a Curve starting from the circle. Using InterpCrv command we will create such curve from Front viewport: (you can start using OSnap if you haven’t already – Near would come in handy here)

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Using Mirror command we need to mirror this curve to the other side.

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Using Trim command we need to trim the Circle:

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I have almost perfectly hit the curve direction and smoothness and actually the curve is visually tangent to the circle. In reality that isn’t the case, so we need to fix it. We will match our curve onto the circle with Match command:

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Here you can see the black curve on the left, this is how the curve will be adjusted to match the tangency. So, now you see I didn’t actually hit the tangency manually. Do this same step for the right curve as well, and join all three into one:

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If necessary, using PointsOn you can change your curve a bit. But you will see if this is necessary after you make a surface. Using Pipe command we need to create a pipe surface. Use 0.2 as radius:

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Here you see this needs some adjustments. So, first, try moving it up a bit to see if this can fix it. If not, using PointsOn you will need to adjust the curve itself.

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For the purposes of this course, just moving this wire will do.