What is the deal with curves? (curve control point handle )

   8394   6   2
User Avatar
Member
40 posts
Joined: July 2005
Offline
Okay I decided to sit down yesterday and start my lamp assignment for the 3dbuzz class, and everything is going pretty well for the most part. I answered a few of my own questions, and made some pretty big mistakes (End Caps are the devil!!! POLYCAP if your going to fuse points with another surface. Same goes with the SKIN OP; if your using that make sure you have Preserve Shape unchecked, or your going to have duplicate edges and points, which turns out to be a nightmare.)

Well back to subject (sorry about the rant) of curves. How come when curves are created in Houdini there are no little handles. to control the contour of the curve? Is it possible to have contoured curves using polygon curves, or am I asking too much? I am used to the Path tool in Photoshop to where I can convert a point to have a hard edge and then go to the next point and make that have a smoot edge. I thought the Bezier curve option would give me some extra control with control handles, but there are not any ): What gives?

Here is a picture of what I am describing.
http://www.geocities.com/klarusboy/curveProblem.jpg [geocities.com]
as always the link will not work if you click on it. you must cut and paste the URL into your browser.

-capin_crunch
cheers
User Avatar
Member
403 posts
Joined: July 2005
Offline
There are control points for Houdini curves. There are three ways to control them, depending on the intention.
The first way is to finish the curve, breifly deselct the CurveSOP, or select another SOP, then go back to the CurveSOP. When you do that it shows originally created points. You just drag them around.

The second way is to use EditSOP. Append EditSOP to CurveSOP from icons menu above the viewer. Then choose points (from left side menu) and sculpt away. EditSOP was not intended to be an animatable SOP. Its really used for continiuous repositioning of points, or as a branched-off SOP to create blend(aka morph) targets for BlendSOP.

The third way is to use TransformSOP. This SOP is intended for animatable point movement. Every TransformSOP tile will transform only point or cluster of selected points. When this SOP is made Persistent, a grab handle is always available on screen in Geometry and Objects view. Very handy when used in combination with spline IK.
Also this is, IMHO, Houdini's direct counterpart to cluster animation in Maya.
Compare the two.
In Maya (in Animation) user selects cluster of CV's or vertices, and defines a cluster. The cluster could be a cluster, or lattice, sculpt handle, etc.. Then the cluster's position is constrained to bone, or null, or some other PSR (position, scalar, rotation) controller.
In Houdini you similarly constrain the PSR channels of TransformSOP to a bone, a null, or whaterver. Using simple expression in PSR channels, or using CHOPs.
So the logic, and technique is very similar to the two. With Houdini's approach being more flexible, and both being very effective.

Modeling is Houdini is really good. I only see two shortcomings in relation to Maya. First is that NURBS toolset of Houdini is not as robust as Maya. Second is the lack of polygonal beveling. Otherwise, Houdini is a marvelous modeler. It handles complex polygons(5+ points) in a superior way, compared to Maya. I have been working with layers(in Maya, Rhino, and formZ) for years, but have come to conclusion that branches are better then layers, on the balance. Maya's sub-divisional surfaces are of hierarchical nature, which has certain advantages over cage derivative sub-division in Houdini, especcially during rigging, but Houdini has better polytools for cage construction.

Dave Rindner
User Avatar
Member
170 posts
Joined: July 2005
Offline
Another way is to rightclick on curve Sop in network editor (or rightclick on curve in viewport) and choose “Geometry spreadsheet”. In the spreadsheet you can adjust the “weight” of a individual CVs and shape the curve the way you want. For reference read “Geometry Types” PDF file.
Chapter “Splines”.
The Things I Do For Love!
User Avatar
Member
403 posts
Joined: July 2005
Offline
Stremik.

I noticed that you are in Chicago. Where in Chicago are you working, using Houdini?
Thank you

Dave Rindner
User Avatar
Member
170 posts
Joined: July 2005
Offline
I'm working from home. Web design, Flash animations…that sort of things.
But I don't use Houdini for work. It's a hobby.
Strangely, there is not many people in Chicago who would be interested in Houdini. At least not that I'm aware of.
The Things I Do For Love!
User Avatar
Member
344 posts
Joined: July 2005
Offline
I'm in Chicago as well, so there's at least two Houdini users here. Not working though, just doing contract work. Hopefully I'll get a new fulltime job before the end of Feb.
User Avatar
Member
403 posts
Joined: July 2005
Offline
What happened to Filmworker's Club on Wabash Ave.? I recall that they were some pioneers in Houdini uses and created a cool spot for Euro market, for Johnie Walker Black scotch.

Dave Rindner
  • Quick Links