Week_2

This week is a look at some of the basic construction techniques in 3dsMax. Covering the loft, spline construction, extended primitives, modifiers and sub-object modeling.


sec:1
Lofting and it's possibilities.

Lofting
1
Draw out 3 splines, a line, a circle and a star.
So they are laid out side by side in the perspective view.
2
Open compound objects from the create menu dropdown, select the line and the loft button activates so you can select shape, (if you have shape you select a path), click on the circle and it lofts along the path.
 3
F3 to examine path and Path parameters.
Enter25, that is 25% along the path from the start of its creation. A yellow marker. Set path at 50% and get star shape. The path now has a circle base and a star top.
4
Move the shapes to show they are separate from the loft, also sit path outside of the lofted object.
5
Open the skin parameters in modify, open the end cap and examine the effect of the adaptive path steps.
6
Separate the circle, star and line so they are clearly viewed, examine the effect of altering the radius of the circle in the modify panel. Examine also the effect of sub-object manipulation on the vertex level of the star shape as it translates to the lofted object. Examine the spline rescaled.
manipulate loft sub objects.
7
Make an alteration on the loft object. Deselect all, select loft object, open the loft in modifier. Select shape and set star to 100% then move the circle shape up to about 60 to give a semi plant like shape.
adding scale deformation
8
We have our shape and so far the only modification is via the circle, star or line alterations. Another alteration is via the scale deformation. Open deformation and scale down the base by lowering the left hand point a bit. (about 65).
 9
Insert two bezier points along the path and set a curve that goes up from zero on the horizontal axis, to a hill curve at about 30% along to a trough at about 70% along the horizontal axis in the deformation panel. Again in the deformation panel at 0, set the point (mouse right click) to a bezier corner and move the handle so it rises steeply, also drop that left most point to zero (this should give a curve base to the lofted object).
 

10
With the caps end remove from the loft object the thickness is just a set of plane polygons. Thickness can be added via the shell modifier. Set the inner amount to 0.1. After the shell examine the shape for its stability. Alter the base to be a bit more of a stable base and perhaps scale down the top of the lofted object.
11
Object now has shell and loft check in the loft the shape steps and the path steps, dropping them down to what is acceptable before the shape begins to look bad.
12
Apply a smooth modifier, by default it is off so apply Auto Smooth. Try to get a smoother base by playing around with the threshold to see where the edges begin to smooth (thresshold probably about 65)
 



Sec:2
Spline manipulation and extended primitives in construction of a bench seat.

Set up unit system (metric/centimeters) and the grid system (right click on snap/home grid/grid spacing=10cm, major lines=10, perspective view grid extends=20)
1_
Keyboard enter a rectangle in perspective view (Pv). Length=100, width=200
2_
Select move and set z=0.5 in Pv. Shift and make a copy about 20cm. Collapse to an editable spline and attach to the original.
3_
In segment level, set the snap grid to vertex and create line from the corner top to corner bottom vertices. Repeat for all corners. Still in segment, shift copy a corner segment to sit just left of centre, Copy that to be just right of centre. Repeat so there are four central support struts.
4_
Apply a sweep modifier. Examine the effect with size reduction. Set to bar and reduce sizes. 
Examine cylinder and drop down radius. Revert to bar profile. 
And base should be as such.

 
5_
In Pv use keyboard creation to create base support for cushions. 
Create a box. L=100, Width=200, Hight=5cm- create and sit on top of the frame.
6_
Create a cushion from the extended primitive section via a chamfer box. Set at length=100, width=100, height=15 and fillet=0.5centimetres
7_
Shift and position to one side .Then Shift click to copy to the other side. Select one of the cushions and isolate and apply a vol. select modifier. This allows info to be passed up and down the stack. 

8_
In the vol. select, set stack selection to vertex and drop down to the gizmo level. Examine the gizmo scaled and moved and with the soft selection ‘on’ and the ‘fall off’ adjusted. With the selection wanted apply a ‘push’ modifier and examine the effect of different push values.
9_
With the required distortion to the cushion delete its vertices at the bottom by applying another vol.select. set at vertex and rotate to see the bottom of the cushion. When the selection suitable apply another modifier.  Apply a modifier ‘DeleteMesh’ and the bottom of the cushion should be removed.

10_
Rotate the cushion to see the top and apply a MeshSelect modifier to override the effect of the stack. 
11_
Add a noise modifier and set the strength to 30,30,30 for x,y,z and decrease the scale to see the various effects. Set to acceptable level. Perhaps strength=5 and scale=20 As seen in the left cushion below.
12_ 
Un-isolate the rest of the bench seat to check the various effects on the manipulated cushion.

Sec:3
Manipulation of the sub object polygon in converting a basic box to a variety of molded object such as a seat to a stool. 

Polygon ModelingDraw out a spline shape for the base and lathe it. Draw out a cylinder as shown at its centre and a chamfered cylinder again as shown, centred and sat as shown. 
 I will drop the file on the shared drive if needed. Look at _stool base.max

1_Open the 3dsmax file: bar_stool base.max
 
2_
Draw out a box in the top view(Tv). Set the segment to 4x4x4. Convert to an editable polygon.
 
3_
Delete the polygons on the  -x side and add a symmetry modifier. Weld seam should be ‘on’.
 
4_
In poly sub object mode ‘show end result’=on and add a turbo smooth modifier and check different iterations.
 
5_
Drop down to the polygon sub object level and with ‘show end result’=off select the two inside top polygons and extrude downwards. Check if extra polygons have been created and delete them. Turn on ’show end result’ and check.

 



6_
Now in top view it is time to round out the seat, using the stool base as a guide. This is clumsy but can be effective. Change to edge mode and begin to move all perimeter edges inward, Using the underlying stool base as a circular guide. This is the methods big draw-back. But working carefully can give a fair approximation of the base. Edge not vertex as shown below.

 
7_
Taper the bottom of the seat after deleting the underneath polygons. Show end result =off examine the base and select the polygons and delete.
Remember to keep using the show end result 'on' and 'off'.
 
8_
Select the bottom edge and loop to select all the edges at the bottom of the seat. Change the reference coordinate system to world and the use coordinate tranform  centre to scale down in the XY axis  


9_
Clean up the vertices at the top edge. Use the various constraints necessary in show end result ‘off’


10_
Add a horizontal loop scale and shape and collect top polygons and tilt via rotate to give the slope to the stool