View Full Version : Alpha into geometry

03-09-2007, 03:50 PM
I know there must be a simple answer I am overlooking, it's nagging at me that I should know this and it's easy. I've searched and can't seem to find it. I have a disc with an alpha channel and mat applied to it. I would like to make the disc into the geometry that shows when the alpha map is applied. Current state to object doesn't seem to work. All is editable also. Can someone enlighten me please? :-) Image attached. It's the cream I need to make into actual geometry. Release 10.



03-09-2007, 03:57 PM
just off the top of my head here - take the alpha and trace its contours as a spline, toss the spline into an shallow extrude nurbs and then do current state to object. Drop it into a HN cage.

03-09-2007, 04:21 PM
You could also consider using the alpha as a displacement map, then use your MoGraph displace deformer to turn the result into an editable mesh.

03-09-2007, 04:50 PM
Hi Damsel,

You could also throw your alpha map into the vectorizor (a type of spline object), convert it, and then put the resulting spline in a loft nurbs. Further editing would be a snap, too. If you don't need to edit the spline then just put the vectorizer as a child to the loft nurbs without converting.


03-09-2007, 05:36 PM
its funny how you can work with a program for years and not see a tool there in front of your nose. i had to check out this "vectorizor" thingy you spoke of, and wow! its like ai's live trace but in c4d! Thanks for shedding some light!


03-09-2007, 08:01 PM
I'm a neophyte trying to do the same thing, and
don't understand what to "convert" to. Or just how you
would trace the contours.

03-09-2007, 08:09 PM
I'm a neophyte trying to do the same thing, and
don't understand what to "convert" to. Or just how you
would trace the contours.

Hi Robcrumb,

Just place your alpha image into the vectorizer and hit the "c" key to "convert" it to a spline that is editable.


03-09-2007, 08:39 PM
Thanks, Ernie.
I still can't get this to work.
I created a new material,
and imported the Tiff alpha for the material alpha.
Applied the material to a plane.
Parented the plane to vectorizor.
Nothing happens when they
are parented to loft nurbs

I then just applied the texture to vector.
Still nothing.

03-10-2007, 11:55 AM
Thanks to all for the great instruction! They all worked and I learned about the vectorizer too. :-) robcrumb... when you add the vectorizer to your scene and click on it in the object manager, down in the attributes manager you will add your alpha image to the texture box under "object properties". That will create a spline in the shape of your alpha image. Then drop that into a loft nurbs and you will have the geometry of your shape. :-)

03-11-2007, 06:11 AM
Thanks Damsel. I got the alpha into vectorizor, so the shape now appears on X and Y. The only problem now is not being able to extrude on the Z axis.
I tried parenting loft nurbs to extrude nurbs,
but it doesn't work. Also tried M + T but extrude was greyed out.

Extrude nurbs will work on a vector object from illustrator.

Maybe the only solution for an extrude is import the alpha into illustrator and
outline it there - then import into Cinema?

03-11-2007, 06:54 AM
Hey Rob,

If you make the vectorizer (or spline if you converted it) a child of a Loft nurbs you should get a planar object with the outline of the vertorizer (spline).

If you want depth simply make your vectorizor (or the resultant spline if you converted it) a child of an Extrude Nurbs.


03-11-2007, 10:21 AM
Also, instead of dropping the vectorizer into a loft NURBS, try dropping it straight into an extrude NURBS.

03-12-2007, 01:50 AM
Thanks! Vectorizor to extrude nurbs was perfect.

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