LD Assistant's 3D Modeling by Rufus Warren
With 3D modeling, you can design using solid, surface, and mesh models. Create new 3D solids and surfaces, or sweep, combine, and modify existing objects. Create or convert objects to mesh to obtain enhanced smoothing and creasing capabilities. You can also use simulated surfaces (3D thickness) or wireframe models to represent 3D objects.
Solid Models
A solid model is a 3D representation that has such properties as mass, volume, center of gravity, and moments of inertia.
Solid Models
Solid models contain the most information and are the least ambiguous of the 3D modeling types. You can analyze solids for their mass properties and export data to applications that do NC (numerical control) milling or FEM (finite element method) analysis.

Use solid models as the building blocks for your model. You can start with primitive solids such as cones, boxes, cylinders, and pyramids. Draw a custom polysolid extrusion or use various sweeping operations to create solids whose shapes conform to a path you specify. Then modify or recombine objects to create new solid shapes.
Surface Model
Complex solid shapes are easier to construct and edit than legacy wireframe models. However, if needed, you can explode a solid to break it down to regions, bodies, surfaces, and wireframe objects.
Note: When you work with 3D solids, you occasionally see messages that refer to ASM or ShapeManager. ShapeManager® is the Autodesk technology that provides 3D solid modeling capabilities to LD Assistant Ac and other products.
Surface Model
A surface model represents an infinitely thin shell that corresponds to the shape of a 3D object.
Surface Model1
You create surface models using some of the same tools that you use for solid models. For example, you can use sweeping, lofting, and revolving to create a surface model. The difference is that surface models are open ended. Solid models are closed.
Mesh Model
A mesh model consists of vertices, edges, and faces that use polygonal representation (including triangles and quads) to define a 3D shape.

Unlike solid models, mesh has no mass properties. However, as with 3D solids, you can create primitive mesh forms such as boxes, cones, and pyramids, starting in LD Assistant Ac 2013. You can then modify mesh models in ways that are not available for 3D solids or surfaces. For example you can apply creases, splits, and increasing levels of smoothness. You can drag mesh subobjects (faces, edges, and vertices) to deform the object. To achieve more granular results, you can refine the mesh in specific areas before modifying it.

Use mesh models to provide the hiding, shading, and rendering capabilities of a solid model without the physical properties such as mass, moments of inertia, and so on.

Featured Rendering - by Andrew MacKay

CAD Articles
Create Selection Sets with Quick Select. by Danny Korem
Frequent tipster Danny Korem sent in a tip to help you select the right objects in your AutoCAD file.
"We probably spend 80% of our time in AutoCAD on editing and modifying existing data, and the remaining 20% on creating new data. That's the reason that creating selection sets effectively can catalyze our tasks.
"There are several ways to select objects, but in this tip I'll focus on the non-picking ones. The two goals are to select objects quickly and easily, and to select them all at once (once you trust what you're doing, there's no need to zoom and pan to select, and no tedious selecting and deselecting).
"So, here's the drill: right-click and access the Quick Select pop-up floating menu option, as shown below. Click here to keep reading

How to: create DWF/PDF automatically when you save AutoCAD drawing by Edwin Prakoso -
Do you need to create DWF or PDF for your drawing to share it with your coworkers? Sometimes you have to do this because not everyone have access to AutoCAD. Of course, you can ask them to install DWG TrueView, free DWG viewer from Autodesk. But not everyone want to install it, especially if they don’t have a good hardware.
PDF probably is a better choice if you often share your drawing with non CAD users. Almost everybody today has PDF reader installed in their computer. And you can open DWFx by using Internet Explorer 7 or later (doesn’t work with other internet browser, only IE. Try this link to open a sample DWFx)
Auto Publish
AutoCAD offers automatic publish to DWF or PDF. You can choose it to create DWF/PDF automatically when you save your file. When you share your drawing on a shared location, you can be sure if the PDF is also updated. No need to worry that you forget to update it! To enable Auto publish, open AutoCAD options. In ‘Plot and Publish’ tab, you can enable Automatic Publish on the bottom left of the dialog.
Click here to keep reading

Mouse Wheel Tips for AutoCAD Users By - Lynn Allen, You Tube Click here for video

Turn off ViewCube in AutoCAD by Michael Rotolo, The Mad Cadder
If you are like most users of AutoCAD and do not create 3D content, you probably do not use the ViewCube in the top-right portion of the drawing window. Click here to keep reading

Tips & Tricks: Using the Shift Key in AutoCAD by John Flanagan's Blog
AutoCAD – Shift for a Change (I didn’t know it could do that).
On AutoCAD training courses, delegates are often surprised by the versatility of the Shift key. Several delegates have commented “I didn’t know it could”. Using the Shift key in conjunction with the mouse and right click menus will greatly improve your efficiency and productivity in AutoCAD.

Tips & Tricks: Using the Shift Key in AutoCAD

The SHIFT key is very versatile; it provides other options as well as changing some commands.

Shift + Right mouse button will bring up your OSNAPs during editing commands providing your Right Click options are set accordingly in Options > User Preferences.

Shift + Left mouse button will remove objects from your selection set providing you are selecting the objects before issuing a command.

If you want to FILLET or CHAMFER with a 0 distance, start the FILLET or CHAMFER command, pick your first line, hold down shift and pick the second line. It will fillet with a zero radius without changing the radius you may have previously set. Click here to keep reading

Thank You!
Design & Drafting appreciates your interest in our products. Please forward this newsletter to your friends and associates, however, NO part of this newsletter may be used without permission. © Copyright 2013 by Chicago Stage Equipment Company Inc. D.B.A. Design & Drafting. Autodesk, AutoCAD, AutoCAD LT, DWF, DWG, DXF, ObjectARX are registered trademarks or trademarks of Autodesk, Inc., and/or its subsidiaries and/or affiliates in the USA and/or other countries. All other brand names, product names, or trademarks belong to their respective holders.© 2012 Autodesk, Inc. All rights reserved.
Rufus W Warren III Editor