Modeling a Pencil
Modeling the tip of the pencil
We will begin by modeling the lead tip of the pencil. The tip of the pencil most closely resembles a
The Landscape Object
The bottom edge of the cone will be clipped to create a jagged edge. First, create a
Reposition the cylinder vertically so that its top end lies completely within the Landscape object. The purpose of all this is so we can fuse both objects to server as a "hull" from which a helper object will be created from the union (intersection) of these objects. Create a
In order to make the tip of the pencil visible we must remove the Boole Object from the cone. To do so, create a new
How jagged the pencil tip’s edge turns out is determined by the shape of the Landscape Object. Use the Landscape object’s Seed parameter (Object tab) to modify the shape of the Landscape object. This can be useful if, for example, you are creating several pencils and want to avoid a homogenous look.
Free-form deformation using the FFD object
In the Object Manager, make the FFD Object a Child object of the Cone object. Switch to the Use Point Tool and move the points of the FFD object around to create a non-uniform tip (see image below). In doing so, the cone’s lower edge should remain unchanged. Try to modify the tip of the cone so it looks like it has already been used to write.
Modeling the pencil shaft using Extrude objects
We will now model the shaft of the pencil. We will do so using an Extrude object in conjunction with an n-Side Spline since this will let us most easily modify the hexagonal shape. We will later be able to easily adjust the number of corners, the length and even the rounding of the edges. The Extrude object will allow us to modify the length of the shaft as well as the shape of the rounded edges at its end.
By moving the n-Side object up you can later adjust the overall length of the pencil.
Switch to the Extrude object: Caps tab and set Start parameters to fillet cap. Set each parameter’s Steps and Radius values to 3, respectively. If the Fillet Type parameter is set to Convex, the object’s bottom edge will be slightly rounded, this rounding (fillet) consisting of three segments. Note that a fillet automatically increases the size of the object’s profile. If you want to avoid this, the Constrain option should be enabled. The end of the Extrude object should be sealed with a simple cap surface without any additional filleting. When working with Boole objects it is important to know that these objects, depending on the Boolean Type used, often only work with objects with a closed volume.
Creating Boolean objects with Instances
Next, we will trim the end of the Extrude object just beneath the tip, thereby matching its irregular edge to that of the tip. We will do this by creating an intersection between the Boole Object being added, the Landscape Object and the Extrude object. Only the Extrude object intersection, which lies within the Landscape Object and its fused Cylinder Object, will remain visible.
In the Object Manager, select the Boole (union) object, then select the
An Instance object can be moved and rotated independently of the reference object. It can even be scaled independently by switching to the Model mode before doing so. When in Use Model Tool mode, an object’s points are not modified, rather its axes are lengthened or shortened. Therefore, objects that contain to editable points can also be stretched or scaled using this mode. For example, a sphere that has not been made editable can be stretched to an ellipsoid or even squashed into a disc. In our example, however, our Instance object will remain unchanged. This bears the advantage that we can, if desired, later modify the shape of the Landscape Object and update the Instance Object accordingly.
Using two objects to create an intersection
Create a new
Creating a negative shape
What we need to do now is sharpen the tip so it looks more like the actual tip of a pencil. As you can see, only the lead tip is sticking directly out of the shaft and the tapered wood that leads to the lead tip is missing. What we will do is create this section of the shaft using the same cone that was used to create the lead tip - but how? Using the intersection between the cone and the Extrude object would create the shape we need but would also trim off the bottom part of the pencil’s shaft. What we need is a shape that defines the part of the shape to be trimmed off. For this we will also use a Boole Object. All we need to do is remove part of the existing cone from, for example, a simple Cube Object in order to achieve a negative shape - basically like the shape of a pencil sharpener. Select the Cone primitive and subsequently create an Instance Object. We now need to create an object from which the tip can be subtracted (to create the negative shape). The shape we will use is a simple
Create a new Boole object (
Completing the pencil model
One more step is required so the shape we just created can be subtracted from the pencil wood. You probably already guessed it - we will use a
Create the new Boole Object, this time leaving the Create Single Object option disabled (we’ll explain why later). Make the Boole (shaft) and Boole (negative shape) Child objects of this new Boolean object - make sure the Boole (shaft) object lies above the Boole (negative shape) object in the hierarchy. What’s left is a typical tapered tip of a pencil. The pencil’s shaft remained unaffected.
Click on the link below to open the file with the modeled pencil tip:
Preparing for materials
We left the Create single object option disabled for the last Boole Object we created for the following reason:
If two objects are fused via a Boolean operation their respective materials will be maintained on the resulting Boole object. If, for example, a red sphere is subtracted from a blue cube the result would be a blue cube with a red cavity. If on the other hand a single object is created, all parts will be combined to create that object. Only a single material can be assigned without converting the Boole object to a Polygon object.
Since we definitely want to assign the tapered wood a different material than the pencil shaft it makes sense to leave the Create Single Object option disabled.
Now we can turn our attention to the application of materials. The Boole Lead Tip (subtract) object will be assigned an almost black material since it represents a lead material, and the Boole (taper) object will be assigned a wood material. The remaining part of the pencil can be textured via the Extrude object (shaft). The image above shows what the pencil can look like when textured.
Varying the shape of the pencil
All pertinent parameters of our pencil model can be easily edited or even animated. The n-Side Object defines the pencil’s profile shape and the Extrude object defines the pencil’s length. Make sure that the bottom part of the Extrude object is never larger than the Cylinder object. The shape of the tip can be adjusted using the Cone primitive and the irregular transition between the lead tip and the tapered wood section can be adjusted via the Landscape Object. Use the Landscape object’s Seed value to vary the shape’s irregularity in case you want to create multiple pencil models for your scene. Landscape Object’s Y Size parameter controls the amplitude of the irregular transition. Reducing this value to 0 would create a smooth transition between the pencil tip and the tapered wood section. The Width Segments value controls the number of subdivisions in the Landscape Object and can be used to add detail if increased.