# 1: Introduction
AC3D is a popular 3D object/scene modeller available
for Linux, Windows 95/NT, and SGI. It is very easy to use but powerful too - anyone can
create good looking 3d objects in minutes.
# 2: Examples
Some models built with AC3D (VRML files)
stadium (37kW) plane(15k)
Someone's desk... (37k) Car(13k)
Webpages are available that show off some models that AC3D users have built - some of
the models are downloadable.
# 3: Features
- Multi platform program -
- Windows 95/68/NT,
- Linux, SGI,
- AC3D file format compatible across platforms.
- Easy to use intuitive interface.
- 4 views - 3 orthographic and one 3D at once or individual views.
- Named objects can be searched for within a scene.
- Navigate/Zoom around the 2d views with cursor keys and other single key presses.
- Hierarchical view window.
- Hide/unhide objects for easier/faster editing of complicated scenes.
- Built-in fast OpenGL 3D renderer with adjustable field-of-view - instantly see results
of your actions in 3D. Spin the model or switch into 'walk mode' for Quake-style control.
- Headlight and up to 7 other positionable lights.
- 24-bit colour palette with adjustable diffuse; ambient; emissive; specular; shininess
- Texture mapping support with real-time rendering.
- Configurable to use external renderers such as Povray and BMRT - just select
Tools->Render to start.
- Plugin interface (registered versions only) with source code for existing plugins and a
software development kit.
- Adjustable 2D and 3D grid guide lines with grid-snap function
- Edit at different granularity - groups, objects, vertices
- Full polygon editing. Not just spheres, cubes etc - make a sphere and move the points
(vertices) to deform the shape.
- Manipulate individual surfaces:
- insert/remove vertices
- make holes
- group into new objects
- Create new surfaces/objects around any selection (Convex hull)
- Extrude and revolve 2D lines to make 3D shapes.
- Scale a selection to a specific size.
- Flip a selection (mirror) about X, Y or Z axis.
- Optimize duplicate vertices and surfaces.
- Simple documented file formats allow easy conversion from other forms of data - ideal
for visualizing your own data in 3D.
- Supports many output/input formats including:
- Alias triangle
- VRML1 and 2 and Inventor
- Direct X (via plugin)
AC3D and PHOENICS
Purpose of AC3D for PHOENICS Users
- The creation of facetted objects representing the various elements of the flow geometry.
- Modification of exisiting geometries - change shape and/or colour.
- Repair of existing CAD geometries.
General Rules for Creation of Faceted Objects
- Object must be 3D, even if it is to be used as a 2D object in PHOENICS.
- All normals must point outwards.
- Object must be a closed volume.
- Import formats -
- CHAM .dat geometry files
- STL files
- DXF files
- Export formats -
- CHAM .dat files
- STL files
- Utilities -
- Heal holes in object
- Orient all faces in same direction
- Split into component parts
- Run Shapemaker
- Boolean operations-
The aeroplane example shown above was downloaded from the internet and
loaded into AC3D:
A PHOENICS dat file was exported, and used as the geometry for an object:
Inlet and outlet boundary conditions were added, and the solution of velocities and
pressure was turned on, together with the KECHEN turbulence model. The solution produced
the following pictures:
Pressure on the centre-line and body surface.
Streamlines starting on circles upstream of the plane.
Closer study of the solution showed that the wings generate negative lift, because of
the peculiar cross-section chosen by the anonymous creator.
Pressure on cross section of left wing