swCHIP 1991 January/swCHIP_95-1.bin/demo/siteview/doc/release.txt

Text File | 1995-12-09 | 15KB | 311 lines

SIteView 1.0


          SiteView 1.0  Release Notes                 Page 6

SiteView 1.0 Release Notes

          These Notes contain items of interest about the
          SiteView 1.0 release that are not contained in the
          product User's Guide, or which came to our
          attention after the Guide was done.  We have also
          included some simple tips on getting the most out
          of environmental visualization, and on how to
          increase interactive graphics performance on your
          PC by paying attention to how you do your work.
          If you have other tips or suggestions that would
          be of use to SiteView users, please let us know at
          1-617-674-2199.

User tips

          This section contains a few tips for using
          environmental visualization and SiteView that we
          have acquired from our own experience and from
          that of early users.

          The very first tip is simple:  SiteView 1.0 is a
          new product.  Save to backup often to avoid lost
          data in the event of a system malfunction.

Deleting defining objects or attached objects

          When you create derived objects in SiteView, such
          as surfaces, iso-shells, or stratigraphic
          sections, these derived objects depend on the set
          of defining objects that were used to construct
          them.  For example, surfaces and potatoes depend
          on the measurements or value points that were
          interpolated to form the derived objects.
          Stratigraphic sections depend on the borings
          (vertices) that were chosen to make up their
          panels.  Deleting the defining objects of a
          derived object without first deleting the derived
          object itself may cause SiteView to cease
          functioning.  ALWAYS DELETE A DERIVED OBJECT
          BEFORE DELETING ITS DEFINING OBJECTS.  In later
          versions of SiteView you are not able to delete
          defining objects first, and an instructive message
          appears if you attempt to do so.

          In the same way, do not delete the borings between
          which stratigraphic polygons have been generated
          without first deleting the stratigraphic polygons.
          Otherwise the polygons will be orphaned and
          SiteView will not know how to management them, and
          the system may malfunction.

Performance (speed)

          The good news about environmental visualization on
          Windows is that it is cost-effective and easy to
          use.  The trade-off is that PC's and MS Windows
          are not as fast as big-ticket graphics
          workstations.  Steven Spielberg didn't use PC's to
          make Jurassic Park, but then he's not in the
          environmental business.  So, here are some tips
          for increasing the graphics performance of your PC
          running SiteView.

          Quick mode

          First, much of what you may want to do does not
          require full-blown lighting, shading, and
          rendering of the image your are working with.
          Unless you want a fully rendered picture, put
          SiteView in "Quick" mode by clicking on the Quick
          box at the upper right hand side of the screen.
          This tells SiteView to outline rather than fill-in
          such things as surfaces, potatoes, and
          stratigraphy polygons, and significantly increases
          the speed of redrawing screens.  You can still see
          where a surface or plume is in space by turning on
          "cells-visible" in the Properties... window.

          Grid size, max grid dimension, and contour
          interval

          Second, when you are smoothing a surface or
          creating a potato, try to keep the grid only as
          large as you need to get the job done.  The large
          the grid points, especially with potatoes in 3D,
          the more number crunching SiteView must do when
          interpolating.  You don't need great refinement to
          understand your data or to compose a visualization
          for a report or presentation.  For the final
          product, you can increase the number of grid
          points to get an even prettier picture, and then
          let SiteView run for a few minutes to calculate.
          This gives you both reasonable performance and a
          great visualization to show others.

          The number of grid points that SiteView uses can
          be set using either "grid spacing" or "max grid
          dimension."  Grid spacing is the interval between
          grid points.  Making grid spacing larger, reduces
          the number of grid points.  Max grid dimension
          sets the number of grid points in the largest
          principal direction of a grid.  Making max grid
          spacing larger, increases the number of grid
          points.

          A similar warning applies to selecting the contour
          interval.  A small contour interval (the increment
          in value which separates adjacent contours) forces
          SiteView to significantly increase the number of
          calculations it must make in creating a surface.

          Hardware

          If all else fails--and you believe that quick
          graphics performance might be worth a little extra
          money--there are some hardware solutions to
          increased performance.

          The first of these is more memory (RAM).  SiteView
          runs in 16MB for normal sized sites.  More memory
          makes SiteView run faster, especially if you have
          large, complex visualizations (e.g., fine-grained
          potatoes and surfaces, big windows, or many
          potatoes).

          The second of these is to buy a 90 MHz PentiumÖ-
          based PC.  We have had calls from users who have
          Pentiums, and they say that SiteView renders a
          view in a second or two on their machines
          (compared to 10 seconds or more on a 486).

          For really improved graphics performance, you
          should investigate the world of 3D graphics cards
          for your PC.  Graphics cards can be obtained for
          486 and Pentium PC's which vastly increase the
          speed with which your PC handles graphics.  This
          may give you the best of both worlds, low cost and
          ease of use, with the performance of a high end
          graphics workstation.  You might even be able to
          go into the movie biz.  The cost of a graphics
          accelerator card is between $250 and $1000.
          SiteView 1.5, incorporating the next release of
          HOOPSÖ, will be equipped to drive at least some of
          these boards.

Flat surfaces

          SiteView 1.0 requires that the defining values of
          surfaces have non-zero range.  That is, the
          maximum value of a surface cannot equal the
          minimum value.  If maxval = minval, SiteView
          calculates in an infinite loop.  This will be
          fixed in SiteView 1.5.

Printing

          The intense visualizations that SiteView generates
          also generate large postscript file sizes when
          sent to a printer.  In some cases these file sizes
          may be too large for your computer or your
          printer.  This is especially true when you are
          using smoothed shading and lighting, and when you
          are using Z-Buffer.  Z-Buffer causes SiteView to
          buffer the entire image in memory before drawing.

          To reduce print file sizes, you should use the
          Production Mode hidden surface algorithm under the
          Options window, and use Flat surfaces under the
          Lighting window.

Visualization

          It takes most people a little while to get used to
          working in true 3D.  So, here are a few hints to
          get you started.

Perceiving 3D

          What you see on the computer screen is, of course,
          a two-dimensional image.  Lighting, reflections,
          shading, perspective and other visual cues "trick"
          your eye by mimicking what a 3D image would look
          like.  The result is that creating a compelling 3D
          visualization with a 2D screen demands artistic
          effort.

Lights and reflection

          SiteView allows you to light potatoes, surfaces,
          and other objects with both ambient light and a
          directed light source.  The strength of the
          ambient light is about 30% of the strength of the
          directed light.  The directed light allows you to
          create reflections (highlights) on 3D objects.
          These reflections give dimension to your images.
          When you first create a new 3D view, the directed
          light source is turned off.  When you create a
          potato without directed light, it is difficult to
          see its 3D shape.  So, its always good to have
          some directed light on when you are working.
          Changing the direction of the light source can
          have a big effect.

          Note that, in SiteView 1.0 the option of placing a
          light source in line with the viewpoint (i.e., on
          the camera) is not available even though the menu
          option has already been placed on the lighting
          window in anticipation of Release 1.5.

          SiteView allows you to change the color of the
          directed light source.  This option is of
          negligible use when you have color shading by
          attribute value turned on, but can be highly
          effective when visualizing a potato or surface
          with light colored faces.  For example, try
          creating a potato at some constant iso-value and
          color its faces white or light gray.  Then turn on
          a light source colored, say, green or red.  The
          potato will have colored highlights on the sides
          facing the light source, and deep shadows on the
          sides facing away.  In Release 1.5 we hope to have
          multiple directed light sources, which will allow
          you to highlight different faces with different
          color lights.

Perspective

          When you turn on Perspective in the Viewpoint
          window, lines of sight converge away from the
          viewer.  This mimics the normal sense of
          perspective that you get when viewing objects at a
          distance, and enhances the perception of three-
          dimensionality.  In fact, it is difficult for most
          people to easily perceive 3D when perspective is
          not turned on.

          Without perspective, a view is drawn
          "orthographically."  For some applications,
          especially in engineering, orthographic views are
          preferred, because they retain true distances.

          One place that orthographic views are almost
          always preferred is when looking straight down on
          the site.  With perspective turned off, the top-
          down view resembles a traditional plan view map.
          If you now turn Hidden Surfaces off in the View
          Options window, you can change the drawing order
          of layers and objects using the Send to Front and
          Send to Back commands under the View menu.  These
          commands are useful only in the top-down view.

Viewpoint in/out vs. zoom in/out

          Some people confuse moving the viewpoint in and
          out with using the Zoom tool to zoom in and out.
          These produce distinctly different results, and
          one or the other will usually be preferable,
          depending on the effect that you are trying to
          achieve.

          Moving the viewpoint in and out from the Viewpoint
          window in effect creates a "walk through" of the
          scene.  The viewpoint moves in toward the image or
          out away from it.  As the viewpoint moves, the
          relative angles that different lines or surfaces
          make with the viewpoint change, just as if you
          were walking up to the scene.  The Zoom tool
          changes the magnification of the current view, but
          does not change any of the relative angles of
          objects in the view.

Data import

          You can import data into SiteView either from DXF
          files or tab separated value (tsv) ASCII tables.
          In version 1.0, the tabular data must be formatted
          in rows.  That is, each row in the table is a
          separate data object, and each column is a data
          field.  Version 1.5 will accommodate both row and
          column formatted data.  In Version 1.0, the "Swap
          Rows and Columns" toggle box does not function.

          Note, you may often want to import location points
          (i.e., (x,y,z) point data).  These should be
          imported as "Value Points."  A value point has
          (x,y,z,value) attributes.  However, the value
          field can be left blank.  The data object simply
          called "Point" refers to points that you create
          graphically using the pallet tools.  If you
          attempt to import spreadsheet data as simple point
          objects, you will get an error message.  If this
          happens, click on OK, and proceed to import the
          data as Value Points instead.  In SiteView 1.5,
          the simple point data object will not appear in
          the pull down list of data types that can be
          imported.

Menu items reserved for Release 1.5

          Some menu items or command options appear in
          SiteView 1.0 only as place holders for
          functionality that may appear in Release 1.5.
          These options are not functional in Release 1.0,
          and are grayed-out.