

    *********************************************************************
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    **         A u t o S u r f     R E L E A S E  2                    **
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This file contains last minute items of information that did not make
the printed documentation.


========================================================================



    CONTENTS
   ==========


	AutoSurf Release 2 an Overview

	What's New in AutoSurf Release 2

	Platform-Independent Information - General and Feature Notes            

	Tips, Techniques, and Limitations

	Known Problems

	Questions and Answers

====================================================

AutoSurf Release 2 - An overview

AutoSurf is a NURBS based surfacing application that extends AutoCAD 
functionality to include the design of 3D sculpted products. AutoSurf includes 
both state of the art surfacing technology and comprehensive supporting 
functionality. AutoSurf extends the AutoCAD entity suite to include NURBS 
splines, NURBS surfaces, augmented polylines, and groups (collectors). 

AutoSurf includes extensive commands for the creation and modification of 
splines and surfaces. AutoSurf also adds significant enhancements to existing 
AutoCAD functionality with regards to 3D Polyline editing. To add even more 
power, AutoSurf includes new display capabilities including incremental view 
rotations at any user specified angle. 

Overall, the integration of AutoSurf into AutoCAD results in a complete 3D 
sculpted surface application that compares favorably with any other world 
class CAD/CAM system in functionality, while providing superior value to the 
customer.




==========================================================

What's New in AutoSurf Release 2

Of course the key difference for previous users of the AutoSurf
product is that AutoSurf Release 2 is now integrated into AutoCAD. The 
Autodesk Mechanical Division team carefully considered all of the 
supporting functionality required prior to and after surface creation, 
then integrated all of this capability into AutoCAD. This integration 
presented an opportunity to consolidate and rename commands.  Here is an 
overview of all of the AutoSurf Release 2 commands mapped against the 
previous commands. (Please see Chapter 5 of your AutoSurf manual for complete 
information on each new AutoSurf command.).
____________________________________________________________

New AutoSurf Command            Previous Command and Brief Description  
				( * = new command ) 
____________________________________________________________

Acad2sf                         * Converts AutoCAD entities with thickness & 
					AutoCAD 3D Polygon Meshes into AutoSurf 
					NURBS Surfaces.

Ame2sf				* Converts AME solid objects into AutoSurf NURB
					surfaces.

Blendsf                         /SBLN   Creates a blended surface between 
					2, 3 or 4 surfaces/wireframe entities.

Breaksf                         /SBRK   Breaks surfaces along U, V, C0, or 
					C1 "seam"

Breakvw                         /BRAK   Breaks wireframe entities - view dependent.

Cornersf                        /CORN   Creates a corner surface at 
					intersecting fillets.

Createaug                       /AU2D, /AU3D, /SCDT Creates Augmented Lines.

Direction                       /RLIN, /LDRN  Shows and/or reverses wireframe 
					direction.

Display                         /DISP   Changes views, allows incremental 
					view rotations.

Dispsf                          /NBPT, /SNOR, /UVLI, /SLAB       
					Allows interactive changes in the
					display of many surface attributes. 
					New functionality including 
					generation of AutoCAD PolyMeshes 
					for rendering.

Dist3d                          /MDIS, /SDIS    Measures 3D distances between 
					a surface & wireframe.

Editaug                         /AURO, /NDEF    Allows editing of Augmented 
					Lines.

Editborder                      /BRKB, /CHKB, /CLRB, /CLSB, /DELB, /DRWB, 
				/JBRD, /NATB Allows editing of borders on 
					Trimmed Surfaces.

Editsf                          /PULL, /CONP  Allows interactive editing of 
					NURBS surfaces

Editsp                          /PULL, /CONP    Allows interactive editing of 
					NURBS splines.

Ellipse3d                       /ELIP   Creates an elliptical NURBS spline.

Entvis                          /HIDE, /UNHI    Allows any entity(s) to be 
					hidden & later unhidden.

Explode3d                       /EXPL, /UNAU    Allows conversion of entities 
					into their component parts.

Extendsf                        /SUEX   Allows surfaces to be extended .

Extendvw                        /EXTE, /NBET    Allows entities to be extended 
					to another entity/or distance.

Extrudesf                       /TABC   Creates an extruded surface.

Fillet3d                        /FILL   Builds 3D fillets in corners of 
					Polylines or corners of separate 
					wireframe entities.

Filletsf                        /SUFI   Builds fillet surfaces between two 
					adjacent surfaces.

Flowsf                          /FLOW   Creates "Isoparametric" polylines (laying 
					on surface) in U or V direction.

Groupas                         /BLK+, /BLK-, /BLKC, /BLKI, /BLKJ, /BLKR, 
				/BLOK, /SHOB, /UNBL Replaces the previous AutoSurf Block 
					command. Allows collections of 
					entities to be named and referenced by 
					a single name.

Intersf                         /SXSU   Finds the intersection of 2 surfaces. 
					Can also trim the surfaces.

Intervw                         /INTR   Finds single or multiple intersections 
					of 2 entities (in the view).

Join3d                          /JOIN   Allows wireframe entities to be combined 
					into new polylines or splines.

Joinsf                          /SUJN   Allows multiple surfaces to be joined into 
					a single surface.

Line2pt                         /L2PT   Creates Point entities from the 
					vertices of a Polyline or Line.

Linevw                          /NBTA   Allows tangent or perpendicular line 
					creation from other entities.

Listas                          /INFO   Displays information about a selected 
					AutoSurf Entity (surfaces, splines 
					and augmented data)

Loftsf                          /SCUL   Creates a surface from a single family 
					of input lines.

Meshsf                          /SCUV   Creates a surface from two families 
					of input lines.

Modin                           * Allows MOD files to be directly 
					input into AutoCAD/AutoSurf.

Modout                          * Allows AutoCAD files to be output into 
					MOD format.

Normalsf                        /SIDE   Flips the surface normal to the other 
					side.

Offsetsf                        /SUOF   Creates a new surface offset from the 
					original surface.

Offsetvw                        /OF2D, /OF3D, /NBOF Creates an entity offset 
					(in the current view) from a selected 
					entity

Outputaug                       /CDAT   Creates a disk file in APT format of 
					selected Augmented Lines.

Partsf                          /SPAR   Creates a polyline of the profile of 
					a surface in the current view.

Planesf                         /SCPL   Creates a planar surface. Can create
					trimmed surfaces automatically.

Primsf                          /CONE, /CYLI, /SPHE, /TORI Creates 4 different 
					types of primitive surfaces.

Profsf                          * Creates a polyline silhouette of a surface 
					in the current view.

Project3d                       /PROJ, /FLAT  Projects entities in a specified 
					direction onto a plane.

Projectsf                       /SUPN, /SUPR  Projects entities onto a surface 
					in the view or normal to surface.

Purgesf                         * Conserves memory and reduces file size 
					by eliminating unreferenced block
					structures.

Refine3d                        /SIFT, /RSPC  Increases or reduces Polyline 
					point density. 

Refinesf                        /SSFT   Reduces internal patch count in 
					surfaces to a specific tolerance.

Revolvesf                       /SROT   Creates a surface of revolution.

Rulesf                          /RULE   Creates a ruled surface between two 
					entities.

Sectsf                          /SECT, /SECL, /SECR Cuts polyline sections 
					through surfaces.

Spline3d                        /SPLN   Creates NURBS splines from wireframe 
					or direct point input.

Surfvar                         /SUTO, /UVLI, /SETN,    Sets all major 
					AutoSurf default values.

Sweepsf                         /SWEP, /DRAG    Creates swept surfaces from 
					sections and rails.

Trimvw                          /TRIM   Allows trimming of entities to other 
					entities in current view.

Truncsf                         /STRN   Reduces slab surface size to minimum 
					size required for given border.

Tubesf                          /TUBE   Creates a tubular surface around a 
					selected polyline.

Unspline                        /UNSP   Converts a Spline to a polyline of the 
					spline's control points                          


COMMAND RELATED ENHANCEMENTS

ADVANCED OPTIONS
 *As previous surfacing users know, many surfacing and 3D commands can have 
  many options. AutoCAD responds to the initial command by presenting a string 
  of all the possible command modifiers. In order to reduce the length and 
  complexity of always presenting all possible options, many AutoSurf commands 
  were separated into "Standard" options and "Advanced" options. When you 
  issue the initial command, you get either a short list of the most often 
  used options, or none at all. If the option you want is not present, simply 
  type "??", two question marks, and AutoSurf will respond with all of 
  the Advanced options.

DIALOG BOXES
 *In AutoSurf, you have a choice of how you deal with the Advanced Options, 
  by command line or with a "Dialog Box" (Dialog Screen). The AutoCAD variable 
  CMDDIA (Command Dialog) controls this. AutoSurf is shipped with CMDDIA=1, 
  the setting that will display any Dialog Boxes associated with any AutoSurf 
  command. If instead you want to get the advanced options presented on the 
  command line, set CMDDIA=0.  Some AutoSurf commands have I/O operations
  (modin, modout, asvarfile, etc.) that have Dialog Boxes associated with them,
  which is controlled by the FILEDIA.  AutoSurf is shipped with FILEDIA=1,
  the setting that will display any Dialog Boxes associated with any AutoSurf
  command with I/O operations. If instead you want to enter the file name
  (including the path) on the command line, set FILEDIA=0.

  You will find that many of the Dialog Boxes present a clear and logical 
  method to set and verify many variables at one time. You are encouraged to 
  try them and see the extra power offered by advanced options and I/O
  operations. 

SURFACE DISPLAY
 *The display of surfaces may be controlled interactively with the Surface 
  Display Dialog Box (DISPSF). You are free to select surfaces and tune their 
  individual display to suit your requirements. Everything from the smoothness 
  of the polylines that represent the surfaces, to the number of U and V's 
  that represent it, and much more, is available all in one place and acts 
  upon existing surfaces.

  By using the Surface Display Polyface Mesh output, you will be able to 
  generate shaded images of your models. By adding the new AutoVision 
  product, AVE Render, or AVE RenderMAN, you will be able to add multiple
  light sources, shadows, and assign materials to each surface, creating
  very realistic renderings of your AutoSurf work.

  NOTE:  Installing any of the rendering packages after installation of
         AutoSurf may overwrite some files required for AutoSurf or change
         the ACAD search path order.  If this happens, there are some files
         in the support directory and support/source directory to rectify this.

         In support/source:
         Asurfa.lsp gets appended to acadr12.lsp (for the AutoSurf autoloaders).
         Asurfa.mnl gets appended to acad.mnl (for the loading of the asurf 
         menu).

         In support:
         Asurf.hlp gets appended to acad.hlp (for on-line help).

         To get the AutoSurf menus back after installing one of the rendering
         packages, asurf_on.mnu (found in the support directory) must be
         appended to the acad.mnu installed by the rendering package.  This
         new file must then be named asurf.mnu in the support directory.

POLYLINE DENSITY
 *Previous upper limits on the number of points in a line, or augmented points 
  in an augmented line, are gone under AutoCAD/AutoSurf. Of course it's still 
  a good idea to keep these point counts under reasonable control. 

====================================================

Platform-Independent Information - General Notes and Features Notes   

 *Bonus Features
  AutoSurf Release 2 ships with an IGES translator and the automotive translators
  previously available with AutoSurf including VDA.  These are the
  translators that read and write the MOD file format of the previous version
  of AutoSurf.  There is also a bonus command, AME2SF, that converts AME solids to
  AutoSurf.

  The environment variable ADX_SYS=directory must be set in order for
  the bonus MOD translators to be used.  The file readme.trn in the asbonus
  directory gives detailed information about the bonus MOD translators.
  "asbonus" is also the directory where the bonus programs reside.

 *Platform Performance
  The amount of RAM and disk space effect performance depending on the type 
  of job or work being performed. Also there are tools within AutoSurf that 
  can help the user tweak performance. Variables such as surface display 
  tolerance and system tolerance should be utilized to maximize available 
  performance.

====================================================

Tips,  Techniques, and Limitations

=========
Tips

DISPLAY  
*When setting the default U & V line display to 2, certain types of 
 surfaces will not be displayed in a manner that makes obvious sense. Surfaces 
 like cones, spheres, and cylinders will appear incomplete because the 
 beginning U and ending U (same with V) will be displayed at a common 
 location.

TOLERANCE 
 *The system tolerance can significantly affect results of surfacing operations.
  Users should always be aware of the Metric and Inch settings especially when
  translating data from other systems. Use ASSYSTOL to set the system tolerance
  to a value that is properly proportioned to model size. Read Chapter #2, AutoSurf
  Fundamentals for complete details.
 
C0 SURFACES
 *The abrupt corners of a C0 surface may not be obvious to the eye.  A change
  in tangent direction of as little as 0.5 degrees is considered C0.  If a C0
  continuous surface is not obvious, use the "Feature lines" option of the
  FLOWSF command to see where the discontinuities occur.

FILLETSF 
 *The fillet radius should not exceed the radius of curvature of 
  either surface. We cannot trim a surface twice with exactly the same 
  operation (or very close one). For example, if the user already trimmed a 
  surface with FILLETSF, he should not do the same FILLETSF with TRIM option 
  again. If he uses a new fillet radius, the new radius should be 
  substantially different from the old one. 

EDITBORDER
 *The Slab option of the EDITBORDER command creates a closed border on the
  selected surface(s) that follows the natural boundary of the slab.  This
  has an "inverting" effect on any closed borders already on a trimmed surface.
  Any outer boundaries which are on the surface will become inner boundaries
  (or holes) and holes in the trimmed surface become outer boundaries.

REFINESF
 *Although REFINESF may indicate that no change was made in the patch count
  of a surface, it is important to remember that REFINESF can affect other
  characteristics of the surface.  REFINESF may reduce the order, change
  number of control points, eliminate an offset, and make a surface no
  longer rational.  This information can be checked with the LISTAS command.
 
GROUPAS
 *The Join option of the GROUPAS command can be used to create new geometry
  based on the wireframe geometry in the original groups.  The first group
  selected for joining will be copied into the new group.  Then any curves
  in the second group that are within the ASJOINGAP tolerance of the first
  group will be copied and joined.

AUTOMATIC TRIMMING 	
 *Users can create trimmed borders on surfaces that intersect one another or
  by projecting or filleting. It is important to note that using these borders 
  for other surfacing functions (sweepsf, loftsf...) will in most cases create 
  improper or unexpected results, or not work at all. 
  Users should make it a practice to follow these rules:
   * All borders must be closed (no gaps).
   * New borders should not overlap (lay on top of) existing borders.
   * You can not join or extend trimmed surfaces.
   * Trim borders should not self intersect ( >< )

AME2SF - bonus command
 *If you plan to convert the AME solids to the trimmed surfaces, it is better
  to set the AME variable SOLWDENS to be greater than 1 before you create
  solids. Increasing the SOLWDENS variable to a higher value will help the 
  automatic trimming option to trim the surfaces.
 *You should always try the automatic option first unless you only want to trim 
  curves and slab surfaces. If the automatic option can not trim surfaces properly, 
  it will give you slab surfaces with trimming curves so you can project the
  curves and then trim the surfaces manually.


=============
Techniques

 *INPUT DATA. When surfacing, remember that you create surfaces from either 
  wireframe or other surfaces, not thin air. If the wireframe sections you 
  are using to create a surface are "messy" the surface probably won't be 
  any better. If you are using polylines as input, pick on them to display 
  the grip handles, and visually inspect for too many points, or for areas 
  where the line comes back on itself. If the line has too many points, 
  use REFINE3D.

 *INPUT DATA. Often when you receive wireframe data from other sources, 
  you will need to join, or break the data before surfacing. Breaking at
  the sharp corners, or at places of rapidly changing curvature, and then
  surfacing the wireframe can save time in the long run.

 *INPUT DATA. It's possible that you will receive more data than you need
  to surface certain areas. For example, if you are given 10 sections but
  you know that it is a straight blend from the first section to the last
  then by all means use the RULESF command picking just the first and last
  sections. You can measure the distance from the other sections to the
  surface with DIST3D.

 *KEEP IT SIMPLE. You must surface the part for the detail required. for
  example, if you were to surface a part for future NC operations, and 
  there are some drilled holes in the part, you probably do not need to 
  surface these holes in your part. They can be shown by centerlines of the 
  drill. (For rough and finish NC you probably do not want holes in your 
  surface, drill the holes as a later operation)

 *KEEP IT SIMPLE. Again, the simpler the surface created, the faster 
  operations such as meshing of flow lines will work. Picking 100 
  sections to create a surface, when 10 would have sufficed is a waste
  of computer resources.

 *QUALITY CHECKING. If you create a surface, and it happens to be 
  incorrect, don't create a new surface from the bad one.  The new 
  one probably will not be any better. Before using an existing 
  surface to create new surfaces, make sure that the existing surface 
  meets the requirements you need for the part. (Tolerance, shape...) 
  You can check surfaces by cutting sections through them, and examining 
  the sections. (SECTAS)
  
 *QUALITY CHECKING. It is a good idea to cut sections (SECTAS) through 
  your completed part to verify quality. If two sections through two
  surfaces meet and create a sharp corner, where smoothness is required, 
  then the surfaces are probably not tangent. 

 *SHADING. Shading your part will help to verify for smoothness and for
  large gaps. Remember to create the polyface mesh first (DISPSF).

 *TOLERANCE. Remember to keep your tolerance in line with the job
  requirements. If your part is not real critical, loosen up the 
  system tolerance, it could allow your work computations to go
  faster.


=================================
Limits/Additional data By Command

Important feature limitations and constraints
 *C0 surfaces can not be offset with OFFSETSF
 *C0 surfaces can not be filleted with FILLETSF
 *C0 splines or polylines will be exploded to multipoint polylines by OFFSETVW
 *C0 surfaces can not be used to generate offset output with SECTSF or FLOWSF 
 *Offset surfaces can not be joined with JOINSF
 *Rational surfaces are not supported by all data exchange formats 

ACAD2SF 
 *This command may create advanced C0 surfaces. 
  See the Fundamentals Chapter for additional information on Surface 
  Continuity and C0 surfaces. 

AME2SF - bonus command
 *This command can only convert the solids with BFile created by AME R2 to 
  trimmed or untrimmed surfaces. See SOLPURGE command in the AME 2.1 Reference 
  Manual for additional information on BFile entity.
 *The Manual option converts the edge on the solids to NURBS curves and 
  the surfaces of solids to untrimmed NURBS surfaces. The Autotrim option 
  converts solids to trimmed(or untrimmed) NURBS surfaces.
 *The colors of NURBS surfaces are always the same as the color of the top 
  level solid even if the original composite solids have different colors.

BLENDSF
 *You can only blend with weights if blending to exactly two surface edges
  or two sections of augmented data.
 *This command may create advanced C0 surfaces. See the 
  Fundamentals Chapter for additional information on Surface Continuity and 
  C0 surfaces. 
 *Can not blend to trim surface borders.

DISPLAY
 *This command is not valid in Paper Space.  This is also true for the
  shortkeys of 6, 7, 8, dxz, dyz and i since the viewing direction can only
  be 0,0,1 in paper space.  The 5 and dxy will only fit the paper space
  viewport when in paper space.

EXTRUDESF
 *This command may create advanced C0 surfaces. See the 
  Fundamentals Chapter for additional information on Surface Continuity and 
  C0 surfaces. 

FILLETSF
 *This command will not function when C0 surfaces have been 
  selected as the input data. See the Fundamentals Chapter for additional 
  information on Surface continuity and C0 surfaces.
 *When using automatic trimming, the flow lines on the surface should not self 
  intersect. It is also important to note that trims cannot cross over seams 
  and poles.
 *Open trim curves will be extrapolated until they intersect the surface edge.
 *Selection indicates the portion of the surface that should be kept when 
  using the 'trim' option.
 *In cases when the fillet radius specified is greater than the radius of 
  curvature of either of the input surfaces, a self intersecting or 
  overlapping surface may result.

FLOWSF
 *The OFFSET option of this command will not function when C0 surfaces have been 
  selected as the input data. See the Fundamentals Chapter for additional 
  information on Surface continuity and C0 surfaces.

INTERSF
 *When using automatic trimming, the lines on the surface should not self 
  intersect. It is also important to note that trims cannot cross over seams 
  and poles.
 *Open trim curves will be extrapolated until they intersect the 
  surface edge(s).
 *Selection indicates the portion of the surface that should be kept when 
  using the 'trim' option
 *This command does not work under the conditions where the input surfaces 
  intersect theoretically or are tangent to one another. 

JOINSF
 *This command will not function when offset surfaces have 
  been selected as the input data. 
 *This command will not function when Trimmed 
  Surfaces have been selected as the input data. See the Fundamentals Chapter 
  for additional information on Trimmed surfaces.

LOFTSF
 *This command may create advanced C0 surfaces. See the 
  Fundamentals Chapter for additional information on Surface Continuity and 
  C0 surfaces. 
 *The align option will only function on open profiles or curves. Use BREAKVW 
  and JOIN3D to work around this.

OFFSETSF
 *This command will not function when C0 surfaces have been 
  selected as the input data. See the Fundamentals Chapter for additional 
  information on Surface continuity and C0 surfaces.
 *If the offset distance exceeds the surface's radius of curvature a self 
  intersecting surface may result.

PRIMSF
 *This command only creates rational surfaces. See the Fundamentals Chapter 
  on Rational Surfaces and Surface Primitives.

PROJECTSF
 *Selection indicates the portion of the surface that should be kept when 
  using the 'trim' option
 *When using the NORMAL option only the points that have coverage over the 
  surface will be projected. The projection will be based 
  upon the projected points, and then extended to the edges of the surface.

REVOLVESF
 *This command only creates rational surfaces. See the Fundamentals Chapter 
  on Rational Surfaces and Surface Primitives.
 *This command may create advanced C0 surfaces. See the 
  Fundamentals Chapter for additional information on Surface Continuity and 
  C0 surfaces. 

RULESF
 *This command may create advanced C0 surfaces. See the 
  Fundamentals Chapter for additional information on Surface Continuity and 
  C0 surfaces. 

SECTAS
 *The OFFSET option of this command will not function when C0 surfaces have been 
  selected as the input data. See the Fundamentals Chapter for additional 
  information on Surface continuity and C0 surfaces.

SWEEPSF 
 *This command may create advanced C0 surfaces. See the 
  Fundamentals Chapter for additional information on Surface Continuity and 
  C0 surfaces. 
 *Closed curves are not supported as input data when used in conjunction with
  multiple rails.

TUBESF
 *This command only creates rational surfaces. See the Fundamentals Chapter 
  on Rational Surfaces and Surface Primitives.

Other
 *AutoCAD splines are not accepted as input data when the AutoSurf system
  variable ASSPLINECONV is set to NEVER. The system will respond with 
  an invalid entity error if the user does select these splines as input.






=====================================



Known Problems

 *When first opening a file after bringing up AutoCAD/AutoSurf, you are
  prompted to save changes.  This occurs because the loading of the AutoSurf
  menu signals a database change.  To prevent this, set your default drawing
  to "asurf" or set the menu to "asurf.mnu" in your default drawing.

 *When using EXTRUDESF to extrude down a two point line, the display of the 
  line will remain highlighted after the extrusion operation has been 
  completed until a redraw is performed.

 *Users should refrain from re-sizing the ACAD window. Under some 
  circumstances the system may core dump or bus error.  (Sun Open Windows)

 *GROUPAS - When you do a block/insert of grouped entities, the association
  to the group will be lost.  This causes groups that don't contain any
  entities to sometimes appear in the list of group names when you use the
  '?' to list all group names during a group selection.

 *GROUPAS - The Show option of the GROUPS command will not put the marker
  at the beginning or end of a group if the group starts or ends with an
  entity which is not recognized by AutoSurf.  This means that groups which
  start or end with blocks, AME solids, etc. will not be able to be used
  with the GROUPAS command, Show option.

 *EDITSP and EDITSF  - When using the "Pull" option in conjunction with the
  "Cursor" option, some temporary display data may be remain if multiple
  viewports are displayed. This is easily cleaned up with a REDRAW.

 *Displaying the polyface mesh of surfaces when your Display Tolerance is
  large with regard to your model size can cause your AutoCAD process to hang.
  The Display Tolerance should never exceed the diagonal length of any of
  your surfaces.  Set your Display Tolerance to a reasonable value before
  generating a polyface mesh.

 *Displaying the polyface mesh of surfaces sometimes produces a mesh that
  can cause an ADS termination when attempting to render it.  Slightly
  changing the Display Tolerance and regenerating the polyface mesh will
  in most cases correct this.

 *Displaying the polyface mesh of surfaces sometimes produces unexpected 
  results. A subsequent "SHADE" or "RENDER" may show "holes" or gaps in the 
  surface. Slightly changing the Display Tolerance and regenerating the 
  polyface mesh will in most cases correct this.

 *In the DISPSF dialog box, when both the UV Display Lines option and the
  Display Tolerance option are selected at the same time, the tolerance will
  be ignored.  The display lines for the selected surfaces will be generated
  to the ASSURFDISP system tolerance.  The tolerance can then be changed
  in a separate operation.

 *AME2SF - This bonus command may produce incorrect results when the BFile
  of the AME solid doesn't contain correct information (i.e. there are missing
  edges, duplicate edges, and incorrect edges etc.).


=======================================================

 AutoSurf Release 2  QUESTIONS AND ANSWERS
	
Q. Sometimes when I project lines onto cylindrical surfaces (or any surfaces 
   that span a completely closed shape), the projection or automatic trim 
   option will fail, why?

A. What is happening is that you are attempting to project the data across 
   the "start/stop "boundaries of the surface. In other words, remember that 
   all slab surfaces (with one exception of a blended or corner fillet), have 
   four sides to them. When you make a closed surface (like a cylinder), 
   somewhere on that surface there is a "seam" where the "start edge" lies on 
   top of the "finish edge" of the surface.  The initial AutoSurf Release 2 does 
   not handle situations where you attempt to project entities that span 
   across these "seams", correctly. The solution to these cases is to either
   1) break your data at the "seam" and project/trim each side separately
   or 2) rotate the cylindrical surface so that the lines you project no longer
   cross the seam.

Q. Sometimes when I create a "cylinder type" of surface (not an actual 
   Primitive Cylinder), flow lines and other surface outputs come out 
   "all over the place" instead of consistent, why?

A. Let's use an example to explain this. Suppose you have 3 Circles, all 
   parallel to each other and a few inches apart.  You would expect that if 
   you create a loft surface by picking all three, that you would get a nice 
   cylinder shape, and in fact you will, as long as the 3 circles all start at 
   the same relative place. Picture that you're looking straight down at the 
   3 circles so they appear as one. A Circle has a "Start" and "end". If all 
   three circles all start and end at 12 o'clock (or whatever - all the same), 
   you will get a nice uniform surface with a "start/end" seam that is 
   parallel to the shape of the cylinder. Flow lines (which "flow" 
   proportionally between surface edges), will also be nicely parallel to the 
   cylinder's shape.

   But if the "start/end" points of each Circle are different (perhaps at 
   12:00, 4:00, and 8:00), you will get a cylindrical surface with a 
   diagonal  seam , then any flow lines made from it will be spiral shaped 
   around the cylinder. Surfaces are developed (internally) by taking the 
   input data and mapping it out to a "Parametric square" world where there is 
   a "Top" , "Bottom", "Left", and "Right" edge to the "parametric surface".  
   The more consistent the input data is, the better surface it can be mapped 
   out to. For example, picture how the 1st cylinder example (parallel seam) 
   would "unwrap". If you could lay it on the floor, break it at the seam and 
   unroll it out till it was flat, you would have a perfect rectangle, which 
   nicely maps out to a perfect internal parametric square.

   But if you try to unwrap the cylinder with the diagonally shaped seam, it 
   will roll flat into a parallelogram, it will not map as well to the 
   internal parametric square, and the flow lines will be diagonal. For all 
   surfacing, the more consistent the input data, the more uniform surface 
   that will result.
 
Q. How do I control my surface display so that I don't have what looks like 
   a faceted surface? 

A. The display of surfaces and splines can be controlled by setting the system
   variable ASSURFDISP. You also have the ability to have a tight creation
   tolerance (ASSYSTOL), and a loose display tolerance for highly accurate
   modeling with quick redraws.
   
Q. How can I use the AutoCAD 'hide' command to view my 3d surfaced parts?  

A. Using the AutoSurf command 'dispsf', you can select which surfaces 
   you wish to view, then choose the polyface mesh unhide option.  Now your 
   surface has the polyface mesh turned on and you can use the 'hide' command 
   to view your part.

Q. How do I take my AutoCAD/AutoSurf part, and bring it into Autodesk 
   Mechanical Expert for machining purposes? 

A. AutoSurf Release 2 contains several translators, including an IGES translator, as
   well as the 'modin' and 'modout' commands.  Using the 'modout' command, you
   can convert your drawing to the .mod format.  You will be prompted to specify 
   a unit of measurement for the new .mod file.  Everything in your drawing 
   file will be converted to the .mod format, except for text, dimensions
   and points. Once your file has been converted to the .mod format, you 
   can then bring it into ADX and machine it as you normally would.

Q. How can I turn off my surface normal?  

A. A surface is like a quilt, made up of a collection of patches. Simple surfaces
   may only have one patch, while complex surfaces will have more patches. When 
   you use the AutoSurf 'dispsf' command you have the option of showing all 
   normals. This will generate the normals of each patch on the surface at 
   their U-V 0,0 location. These are drawn as a temporary display entity, and 
   a redraw will remove them.  The surface normal that is always there is the 
   normal for the whole surface, all the patches combined into 1. This normal 
   cannot be turned off. It can however, be set to a very small length 
   (0.0001).  If you are trying to plot your model, and that small of a normal 
   is unacceptable to you, then an alternate surface display can be obtained 
   with the AutoSurf 'profsf' command.  This command creates a profile of your
   surface, and will change the color of hidden lines for an added ease of visibility.

Q. Will AutoCAD's shading and rendering capabilities be applicable to 
   AutoSurf surfaces? 

A. Yes.  Using the AutoSurf command 'dispsf', you can unhide a surface's 
   polyface mesh, thereby making it recognizable for rendering and shading 
   purposes.

Q. How can I tell the difference between my U and V lines on my surfaces? 

A. The default number of U and V lines is set to 5 by 3. Simply count
   the number you have. You can change this by setting the system variables 
   ASSURFU and ASSURFV to any value you may want.  Also in the 'dispsf' 
   command there is the option of showing you which lines are which by using 
   the 'Show U Direction' and 'Show V Direction' option.  Which may be helpful 
   if you are zoomed in close on a surface.

Q. How can I change the tolerance of the polyface mesh? 

A. The tolerance of the polyface mesh is controlled by the system variable 
   ASSURFDISP, which is the display tolerance. We recommend leaving the 
   surface display tolerance set to it's default value, and only changing 
   it when needed for a particular surface.  While in the 'dispsf' dialog 
   box, click on the polyface mesh unhide box, and the display tolerance 
   box. Change the display tolerance to suit your needs. Changing the 
   display tolerance here will only affect the surfaces you have selected.

Q. How will the system tolerance affect my metric drawings?  

A. AutoCAD by default has no units per se. However, the default AutoCAD 
   drawing is a 12 by 9 drawing.  This has to be interpreted as an English 
   system of units. Therefore AutoSurf's system tolerances have all been 
   scaled to reflect an English system of measurement.  If you are going to be 
   working in a metric environment, we recommend scaling your tolerances to 
   also reflect metric units. As you can imagine a thousandth of an inch is a 
   workable unit, but a thousandth of a millimeter is very small.  At the very 
   least you will need to scale your system tolerance (ASSYSTOL) and your 
   display tolerance (ASSURFDISP). If not your drawing file could become very 
   large byte wise, and be very slow and cumbersome to work on.

Q. How can I hide my entities like I could in ADX? 

A. The ADX equivalent of /hide, and /unhi, is the AutoSurf ENTVIS command. 
   The entvis command's first prompt is hide, or unhide. Then you have the 
   ability to hide by all, group, layer, line type, object type, or 
   selecting. The same options are available for unhiding.

