by April 3, 2007 0 comments



Animation and 3D graphics is one of the largest growing sectors today. There
is a high demand for graphics artist specializing in software like AutoDesk 3D
Max, Maya etc. Although Max and Maya are the staple for 3D graphics work, they
both are a world apart in terms of functionality. Softimage’s XSI incorporates
the main features of both of them and blends them into its own interface. We
take a look at how a simple 3D object can be created using NURBS/Curve modeling
in XSI 6.

The interface
XSI offers an interface similar to that of Maya. On startup, you have to choose
which interaction mode you want to use. You can use Softimage’s own interaction
model or if you are familiar with other modeling software and know the common
interaction keyboard shortcuts then you can select the QWERTY tools option. The
main screen is split into four views -top, left, front and perspective-each
having their own title bars with icons for camera selection, view selection,
default axis and wireframe options. On the left is the main toolbar, which
displays various options for creating and modifying options for modeling,
rendering, animation and simulation. The right side has a toolbar for adjusting
various options such as selection and transformation of the objects creating in
the software. On the top is the main menu bar, which displays all the commands
in various menus. At the bottom is a timeline, a script editor alongwith
playback controls and a status bar.

Direct Hit!
Applies To:
Graphics designers, multimedia professionals
Price: Not available
USP: A unique 3D software which integrates the features of 3Ds
Max and Maya
Primary Link:
www.softimage.com

Google Keywords: XSI, softimage

Modeling
We assume that you have the working knowledge of Maya. Now let us create a
simple guitar using curve modeling. On the left hand toolbar, click on Primitive
tab in the Get menu, go to curve and click on circle. A box would pop up, with
the radius and number of subdivisions of the circle. Make the radius 1, and the
subdivisions 10. A circle would be displayed in all the four viewports. Press
‘M’ to enter vertices edit mode. Choose each of the vertices, and press B to
convert them into Bezier knots to get better adjustment capabilities. Now select
individual vertices and drag them up and down so that you get a rectangular
shape. This rectangular shape won’t be perfect, so don’t worry. Once you get a
basic rectangle shape, click on each of the vertices, you would notice that each
vertice displays two extending lines from its centre. Click on the end points of
these lines to adjust each vertex. Once you get a straight rectangle shape,
adjust the vertices left and right, so that you have a rectangle with curved
edges on each of the four corners.

After this is done, press ‘M’ again to get out of vertices edit mode. Click
on the rectangle curve you have created and adjust it as per your reference
image in the top viewport so that it shows at the bottom of the reference image.
Resize it to fit in the image’s displays, and press ‘Ctrl + D’ to duplicate the
existing curve line. Move the duplicate curve upward and resize it as per the
reference image. Continue doing the same process till you cover the entire
reference image’s base. Make sure you duplicate the newly created curve that you
have resized and positioned, and not the main curve you created every time you
duplicate.


Rotoscope helps place
reference images in each viewport and adjust it to provide 3D reference
image in perspective viewport

Once you have made the base of the guitar, duplicate the last curve you made
and resize it to make the neckjoint of the guitar. Duplicate this curve again
and move it towards the top, take at least four curves to get the shape of the
fretboard.

Finally, create two more curves by duplication to create the headstock of the
guitar.


The vertices can be
resized or moved by drag and drop, however, multiple vertices cannot be
controlled at the same time

Surface and basic material
Once all the curves have been placed, start selecting them as per placement
order from bottom to up. Keep Shift pressed and use mouse click to select the
curves. Select all the base curves first and once selection is done, click on
surf mesh in the Create menu of the left toolbar and select Loft. A box with
various options would pop up, just leave everything at default and close the
box. Press ‘5’ on the keyboard to view the surface display in perspective
viewport. To get a better shape, go to the selection toolbar on the right and
click on the small circle just below the Knot tab. From the menu that pops up,
select Curve. Now on the 3D object, click on the desired curve and adjust it so
that you get a proper shape. Do the same for the neckjoint, fretboard and the
headstock. Once the surface has been applied, connect the open curves of the
base and the neckjoint, by selecting the two curves and using the loft feature.
Close lowermost and the topmost open gaps by resizing the associated curves.


The Blinn material
property box provides sliders to get the desired color/material effect on
the 3D object

To apply basic material, ins the get menu on the left toolbar click on
Material and select Blinn. This will bring up a box with slider bars. Slide the
bar till you get the desired color in the perspective view and once done, close
the box.

Press F5 to change the left side toolbar to render toolbar. Click on Render
at the bottom of the toolbar and select scene options. In the box that opens up,
change the scene output to the folder of your choice and leave ‘change the frame
end’ to 1. Click on Preview at the bottom of the toolbar, and your image would
be rendered. Click on ‘Save Image’ button and save the resulting image in the
folder of your choice.


You can save the preview
as an image, render object again and depict the amount of rendering as it
proceeds at the bottom

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