two threads going on here simultaneously -- my fault.... u3d. I understand the file format. Nothing terribly difficult there, at least not if we choose the "not compressed" format. But there appears to be a single object type: mesh. So I'm interested in how that works with all the spherical atoms and tubular bonds which currently are not done that way. Could be a challenge; could be a VERY large file. I'm definitely going to need help.
VRML. camera. Here's what I read: http://www.vrmlsite.com/feb97/a.cgi/spot1.html Maybe you can figure out what they are talking about: <quote> DEF OpenView PerspectiveCamera { position 0 50 500 orientation 1 0 0 -0.25 heightAngle .0034 } 1. position - an XYZ coordinate of world. 2. orientation - radian value for turning the camera through an axis. The orientation flags for XYZ are floating point values. You can use combinations to create isometric view angles, etc. It helps if you have an editor or program to do this, because the calculations are complex. You can treat these as integer flags to turn the camera. Note that the movement is orthogonal to the axis used. Think of this as a camera lens with three steel bars through them. 1. X axis turn: camera lens tilts up and down 2. Y axis turn: camera swings left or right 3. Z axis turn: camera tilts left or right (view is upside down) 3. heightAngle - view volume. Use with care. Like a fish eye lens, it can produce distortions, but also, it lets you see more when camera is closer to an object. Err... "objects are closer than they appear in the mirror" effects. </quote> This writer may be wrong about the axes. Looks to me like an axisAngle definition of orientation to me. I also see regarding VRML 2.0: Viewpoint Specify viewpoints. This node replaces the VRML 1.0 PerspectiveCamera node. So, for example, I see: Viewpoint { fieldOfView 0.785398 position 0 0 10 orientation 0 0 1 0 description "v1" jump TRUE } That's got to be it. Orientation should be the viewer axisAngle. So I suppose it's the "heightAngle" that is the key to removing that distortion. Also: <quote> There are two types of VRML cameras: perspective and orthographic. Perspective cameras have a vanishing point, and orthographic cameras don't. A perspective camera looks more natural to the human eye, so I use it mainly. An orthographic camera does not allow objects in the distance to disappear as one moves away. This is useful when one object is the center of attention such as might be the case in a parts catalog. Try them both. </quote> On Mon, Jan 19, 2009 at 2:49 PM, Angel Herráez <[email protected]> wrote: > On 19 Jan 2009 at 9:44, Robert Hanson wrote: >> There must be some way of defining the VRML view -- look for a >> definition of a 4x4 transformation matrix (includes zoom and >> centering) or a 3x3 rotation matrix. Those are available via Viewer >> methods. > > Don't know what to do with the orientation matrix. > > This is the vrml doc I found: > "The position and orientation fields of the Viewpoint node specify relative > locations in the > local coordinate system. Position is relative to the coordinate system's > origin (0,0,0), while > orientation specifies a rotation relative to the default orientation. In the > default position and > orientation, the user is on the Z-axis looking down the -Z-axis toward the > origin with +X to > the right and +Y straight up. " > > > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by: > SourcForge Community > SourceForge wants to tell your story. > http://p.sf.net/sfu/sf-spreadtheword > _______________________________________________ > Jmol-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/jmol-developers > -- Robert M. Hanson Professor of Chemistry St. Olaf College 1520 St. Olaf Ave. Northfield, MN 55057 http://www.stolaf.edu/people/hansonr phone: 507-786-3107 If nature does not answer first what we want, it is better to take what answer we get. -- Josiah Willard Gibbs, Lecture XXX, Monday, February 5, 1900 ------------------------------------------------------------------------------ This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword _______________________________________________ Jmol-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jmol-developers
