Week 2

Splines & Booleans

Splines

Today I was introduced to the process of creating shapes via the use of splines. Splines allow the user to create virtually any shape they desire from the standard circle or rectangle to text and custom shapes.

Starting with the line tool under splines in the create shapes panel I began to draw an object by clicking in the top viewport to place vertices.

When the left-mouse button is held down and dragged in any direction a bezier vertex is automatically inserted which allows smooth curves to be placed within the shape.

The curves can also be adjusted by selecting the required vertex, the bezier handles can then be manipulated accordingly. The vertex type can also be changed simply by right clicking on it an and selecting a different type including bezier corner, bezier, corner and smooth.

Alternatively if the shift key is held down on the keyboard whilst placing points, the movement of the line is restricted to 90 degree directions, therefore allowing a perfectly straight line to be created.

After placing all the desired points the spline can be closed by clicking on the first vertex, I was then prompted to close the object by a pop-up message giving the option to close the spline or leave it open.

Now that I have produced a complete 2D spline it has to be transformed into a 3D object, this can be achieved in numerous ways depending on the desired result. If creating a glass for example the spline would be left open and then a lathe modifier could be applied to extrude the line around a specified axis. However when using a closed spline I converted it to an editable poly which then made it a flat 3D plane.

I then selected the polygon on the top side and extruded it in the z-axis to create a 3D yet hollow object.

In order to rectify a hollow object, the side without a face needs to be covered over by using the cap option within the border modify panel. Enabling this simply adds a polygon within the selected border, consequently creating a completely covered shape.

	To achieve this the border selection type within sub-object level needs to be turned on (keyboard shortcut "3"). This selection mode basically selects all the connected edges on one side of the object, the cap button was then pressed to cover up the side of the object.

The completed/capped object:

Booleans

I also learnt how to use the boolean function within 3DS Max that allows multiple objects to be merged, intersected, cut or subtracted from one another using a range of options.

To begin with I created two standard primitives using the create menu.

The tube object was then positioned inside the box so that it was deliberately intersecting it, the height of the box was also purposely made shorter than the tube so that once a boolean had been applied it would carve through the middle of it.

After this a boolean was initiated by selecting compound objects in the create panel drop down menu, I then selected the boolean object type. Various parameters are available concerning a boolean and each produces a different effect, in this case I want to subtract the green box (B) from the pink tube (A). Therefore the operation "subtraction (A-B)" has been selected, I then pressed the "Pick Operand B" button and selected the box.

After clicking on the box the following subtraction was achieved:

 

Pro Booleans

Another tool extremely similar to Boolean is Pro Boolean, the main differences being that it allows a considerably larger number of objects to be used rather than just two (A & B). Due to this fact a lot more options are available when using this type of boolean, however it is exceptionally memory intensive and consequently it should be used sparingly when modeling a larger scene for example.

In the images below I have positioned a number of spheres around the edge of a tube to which I then applied a pro boolean, subtracting the spheres from the tube.

Pre Pro Boolean:

 

Pro Boolean Result:

As can be seen on the image above, the resulting pro boolean created a cog/gear type object that has clearly defined teeth produced by the subtracted spheres.