nx large assembly best practices final 1

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Siemens PLM Software

Large Assembly Best Practices




Large Assembly Design Challenge

Designing systems, assemblies, and parts to meet the

requirements of complex products,

in the face of …

large data sets: The term "large" assembly is a

relative one. Large assemblies for some may be

1,000 parts while for others 10,000 or 100,000+…

complex geometry: Nurb surface data

constantly-changing data

large, distributed teams designing

in same assembly space



Large assembly handling in NX

(1) Load Performance and Capacity: Reduce the amount of data per component loaded

(2) Simplification of assembly data : Reduce the complexity of components loaded

(3) Context control: Reduce the number of components loaded

(4) Visualization settings and Memory utilization: Utilize memory more efficiently.

NX contains leading-edge tools and techniques to facilitate working on large assemblies

NX has a long and successful history of providing

solutions for such industries as aerospace,

automotive, heavy machinery, shipbuilding, etc.

where large assembly requirements are a key

element



Load Performance and Capacity

Load Options

What are they?

A set of options that allow you to control how much

and in what form component data is loaded

Important Properties

Lots of settings including:

Load Method - the location of the data

Load Components – all components, no components

or use component filters

Partial Loading – display data only

Determine action that should taken if a component

cannot be loaded

Save and restore specific configurations

Accessible from the Open dialog box

Benefits

Using Load Options effectively is one of the most

important ways to improving large assembly

performance



Only load the components that you need to see to do your job

Load Options: Selective Loading

Principle

Benefit

Faster load times

Less memory used

Technique

Load with “no components”

Open components using:

Assembly Navigator

Component filtering

Bookmarks



Load Options : Lightweight Creation

Faceting tolerance

Faceting tolerance affects

smoothness, performance,

& memory usage

Default value: calculated per body,

based on bounding box size

User-specified value:

Per body:

Assemblies→Advanced→Represe

ntations→Parameters

Per session: Assemblies→Site

Standards in Customer Defaults



Load Performance and Capacity

Reference sets

What are they?

Named sections or partitions of a NX part created in

the Assemblies application

Lets you control the amount of data that is loaded

from each component and viewed in the context of an

assembly


Two types:

Automatic - managed by the system (Empty, Entire

part, Model and Simplified)

User defined - created and modified for your own

purposes (Ex: Mate, Simple, Draft)

Benefits

A well-managed reference set strategy can lead to:

Faster load times

Reduced memory usage

Less cluttered graphics displays



Occasional Piece Part Ref Sets

MATE

MODEL ref set plus mating geometry

SIMPLE

Simplified geometry

Entire Part

Simple Model Reference Set Simple Reference Set



Avoiding & Coping With Assy-Level Ref Sets

1. Use layers to hide unwanted geometry

2. Use assembly-level reference sets with

Add New Components Automatically switch (NX 3)

Possible Exceptions and Alternative Approaches

Customer Default

Create Ref Set Option

User wants to show only a subset of child components

Examples: Show different variants

LH & RH assemblies

Hide Some Components

Arrangement-specific component suppression



Simplification of assembly data

The goal with simplification is to: Provide a method of hiding proprietary data

Reduce assembly complexity

Improve load performance

There are several methods to simplify geometry in NX:

Assembly Level

Assembly Envelope (Wrap & Linked Exterior

options)

Simplify Assembly Wizard

Simple Reference Set

Faceted Representation

Component Level

Simplify Body

Extract Geometry (Timestamp)

Wrap Geometry

Suppression



Simplification

Assembly Envelopes

What are they?

Tools for reducing assembly complexity as well as

hiding proprietary data. Essentially, they create

geometry at the assembly level that can take the

place of subcomponents


Use automatic reference set to specify display of

envelope

Two forms:

Wrap Assembly – provides coarse boundaries and

gives a shrink-wrapped appearance

Linked Exterior - makes an exact copy of external

faces and maintains the form of the original

Benefits

Useful when only an approximation of an assembly is

required (Wrap)

Provides a method of improving load performance by

reducing assembly complexity

Provides a method of hiding proprietary data

Wrap Assembly Linked Exterior



Simplify Assembly Wizard

Simplification – Assembly Level

What is this?

A dedicated wizard user interface that guides you

through the process of simplifying an assembly into a

solid that represents the assembly


The goal to unite all the bodies in the assembly and

remove the interior faces

All bodies are linked into the work part

Covering bodies are used to plug holes and fill gaps

until all the bodies are united into one and the interior

faces are completely isolated from the exterior faces

The result is a single lightweight and airtight solid

Benefits

Helps reduce load times at the expense of geometric

detail

Preserves complex exterior details while removing

interior details



Context Control

Assembly Context Control deals with display, selection & filtering techniques

Assembly context is the set of components you want loaded and visible at a

particular juncture

The assembly context control functions in NX are key to quickly finding,

returning to, and understanding the environment of a specific area to be

worked on

Filtering Techniques

Find Component

Open by Proximity

Product Outlines



Context Control


As your assembly becomes larger and more complex, there is an increasing need for you to control the component parts that you work with and see Large assemblies depend on filters and other techniques to efficiently navigate throughout large amounts of data There are several methods in NX to filter data including:

Component Groups (Filters) Filtered Assembly Navigator Zones Bookmarks



Find Component

What is it?

The Find Component tool sets context by letting you

perform a search for a component based on any

global property


Scope criteria:

By Name

By State

By Attribute

From List

By Size - based on the component's bounding

box

The Status line shows the number of components

that are selected in the current contexts

Benefits

Allows you to locate one or more components quickly

in order to establish context control

Find Selected

Component




Component Groups

What are they?

A set of tools used to set, save and restore logical

subsets of assemblies for assembly context


Primarily used for loading and unloading of data

Two categories:

Functional - use assembly data

Attribute, Zone & Proximity

Organizing – combinations of functional filters

Match All of, Match any of & Exclude from

Can be saved permanently or temporarily

Benefits

Provide productivity through performance - you only

load what you need

Visual clarity - you only see what you want to see

Intelligent component selection

Attribute Search




Zones

What are they?

A method of defining and naming regions of space

within an assembly that can be used for filtering

criteria


Can be defined by auto-generating entire assembly or

explicitly sizing

Two Types: Box Zones & Plane Zones

Zones filter components based on a component’s

bounding box or True Shape filter

Options to select: Box: Inside, Interferes, Outside

Plane: Above, Intersects, Below

Defined and stored at the assembly level

Benefits

Provide a useful way of partitioning an assembly

model into meaningful regions

Very useful for volume comparisons

Filter



Filtering techniques

Open by Proximity

What is it?

A tool that simplifies the process of loading a set of

components that are located in a small region of a

large assembly

Loads all components within a specified distance of

the bounding box of a selected component

Use Cases

When you wish to load large components in the

vicinity of the work part for overview purposes

When you wish to do a "lightweight" or “solid” load of

nearby components to understand your design

context


Optional True Shape Filtering accuracy vs. time

Benefits

Simplifies the process of loading a set of components

that are located in a small region of a larger assembly



Enabling True Shape Filtering

Set customer defaults for true shape (tso) file generation

(see on-line help for guidelines)

If necessary, refile existing parts

with option “-ts”

Creates tso file without re-saving part

Existing users need to ensure

they have set the save option

Setting up tso file generation




Bookmarks and Product Outline

Bookmarks

What are they?

Bookmarks allows you to record, communicate

and restore the working context from one NX

session to another


Allows you to duplicate a current assembly

state in a later NX session

Record options include:

which component groups are applied

what are the active Load Options

which components are loaded

User specific workflows – native & NX

Manager

Benefits

Allows you to quickly reestablish a desired

working context from one session to another

Provides a method of context sharing between

users

Product Outline

Ghost image of assembly that

can be switched on and off



Visualization settings and Memory utilization

Visual Settings



Visual Performance Preferences

Large Model Settings

What are they?

A number of preferences that can dramatically improve

graphics performance/speed


These viewing dynamics preferences are applicable on

rotate, pan, zoom and navigate operations

Benefits

This greatly reduces the amount of memory needed to

change view orientation in the graphics display

Large Model

Fixed Frame Rate - this will allow the system to display a

box of the component/body on repositioning of the

geometry in the graphics window

View Frustum Culling – allows the system to disregard

objects outside of the viewing area



Others…

Changing body color, translucency, or partial shading: o Make the component the Displayed Part before changing anything or in an assembly. Also, make sure only the component (not the body or any portion of it) is selected. Controlling Updates: o In a large assembly, you can save time by delaying interpart updates and then updating at your convenience Saving in Wireframe vs. Shaded o Part files saved with shaded display active will take

longer to load and use more memory o Tests show that a shaded model can take up to 5 times

longer to load than the same model in wireframe

Shaded Mode vs. Partially Shaded Mode o A less memory intensive option to fully shading o This means that only bodies/components designated

are shaded when this mode is active



Hardware Recommendations

Large Assembly Focus

With the rapid changes in hardware and software, any quantitative

recommendations become obsolete within months

The best recommendation (as an NX customer or any other CAD user) is for

you to monitor technologic advances specifically in the following areas:

Physical memory (#1)

Graphics card speeds and capabilities (#2)

CPU speed

Disk access speed and capacity

Server and network speeds



Check system configuration as per standards



Hardware Recommendations

Large Assembly Focus

Tuning graphics card

•Windows Desktop

•Display Properties – Advanced

•select graphics card Control Panel.

•Under application or global presets

•Select NX.

•Start NX

•Preferences – Visualization

• Evaluate Graphics Performance.

•Exit NX



Large Assembly Drawings

The creation and update of large assembly drawings is computationally expensive by nature In particular, the creation of hidden line renderings of views As well as requiring all relevant components to be loaded into the session, the hidden line calculation itself demands significant memory and processor resource NX provides techniques for making the process more efficient by reducing the amount of data that typically needs to be loaded to create or annotate a drawing and its views



Large Assembly Drawings Topics

Master Model Strategy

Delaying View Updates

Associative Extracted Edge Views

Faceted Representation Views

Predefined Drawing Templates



Master Model Strategy

What is this?

Instead of creating the drawing in the assembly itself,

the master model strategy takes advantage of a non-

master document that references the master

assembly


Create through File>New dialog box

Benefits

Promotes concurrent engineering, by enabling a user

to modify the drawing without locking the master

assembly - Drafting and modeling changes can

happen in parallel

Separates annotation data from the master assembly

- which means you can load the master assembly

without needing to load the drawing data into the

session - this speeds up the loading process and

reduces memory consumption



Delaying View Updates

What is this?

A major contributor to performance and memory

usage issues with large assembly drawings is the

amount of resource required to update views (in

particular, the hidden line renderings)

The Delay View Update option allows you to minimize

view updates


Updates can be initiated explicitly at a more

convenient time or by using a UG/Open program

View updates can also be delayed on a per-view

basis

Benefits

Improves performance and memory usage by

reducing the amount of resource required to update

views

Prevents hidden line recalculations when the

assembly changes



Associative Extracted Edge Views

What are they?

An alternative way to display model geometry in a

drawing view by creating a set of associatively

extracted edges

Instead of the model being directly visible in the

drawing views, the system displays a 3D

representation of the model's visible edges


Supports Concurrent Engineering

Associative or Non-Associative methods

The components only need to be loaded when a

drawing update is performed

Benefits

Improves performance by allowing simple annotation,

view edits, and the creation of detail views can be

made on large assemblies without the assembly

components being completely loaded



Faceted Representation Views

What are they?

Renderings of a faceted representation of the

assembly


Can be used for dimensioning

List others…

Update drawing view at a more convenient time

Benefits

Facilitates the quick update and hidden line display of

a drawing of a large assembly

Using faceted representations when creating drawing

views can dramatically improve the performance and

memory utilization of assemblies drawings



Predefined Drawing Templates

What are they?

A capability that results in automatic drawing view

creation by creating a new master model drawing

from a modeling view


The template contains empty drawing views that are

not linked to a model

Drag and drop a model / assembly onto the template

and the views populate with the model Drawing

Templates can include the following: Drawing Borders

Imported Views

Section Views

Exploded Views

Automatic Ballooning

Applies dimensions and annotation

Populate Parts List and Tables

Benefits

Saves considerable time by eliminating repetitive

tasks creating a standard layouts of component parts

/ assemblies

nx large assembly best practices final 1

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