Best Practice for making 3D models useful

Share your 3D models!

Creating a Best Practice on publishing 3D

models for museums

• The Best Practice for publishing 3D models is publically

accessible at the Swedish Nation Heritage Board's home page -

both in Swedish and in English.

• The Best Practice gives a practical overview of making and

publishing 3D-models.

• The Best Practice has been developed through practical

experimental work with several Swedish museums.

• Being entirely web-based, the Best Practice can easily be

updated.

Why a Best Practice on publishing 3D models?

• Improved software and platforms for publishing has made 3D

technology easier and cheaper to use than ever before.

• Publishing 3D models on external platforms makes the collections

of museums visually accessible regardless of time and space.

• Anyone with a 3D printer can print the models. 3D models are also

useful for documentation, research, education, exhibitions, in

VR/AR applications….

• However, due to lack of knowledge, museums usually don't

take the full advantage of what this technology has to offer.

Best Practice – what’s in it?

• Equipment and efficient workflow for creating 3D models.

• Extremal platforms, and how to upload models to them.

• Adding relevant information and metadata to the models, and

making them searchable.

• Practical use for 3D models – exhibitions, printing, VR&AR,

research, conservation, documentation, educational…

Why should museum create and publish 3D models?

• Make collections and places accessible to people who cannot

physically visit a museum or cultural heritage site.

• Make objects in storage accessible.

• Complement to physical exhibitions, where the models can show

angles and details that are invisible to the naked eye.

• Resource for various types of interactive applications, where the

user can turn, zoom, and interact with the objects in web-based or

mobile applications.

• Printed models provide tactile support in guiding and exhibitions.

3D models should not just be viewed as

an end and a method unto themselves,

but as a complement to, and a way of

enriching other media and methods for

cultural heritage interpretation.

This image shows how I use a 3D

model of a Medieval rune calendar as

an aid to recreate it in wood.

The 3D model can be turned around

on the screen, to give a complete 360

degree view of the rune calendar.

Without handling the original

Medieval rune calendar!

Choosing objects for 3D digitizing

• Will a 3D model increase the understanding and experience of the

object? You can make a 3D model of anything, but certain objects

and materials are less suitable for the medium.

• Can the model and information about the model be used for

educational purposes?

• Is this an object with an interesting story to go with it?

How do you make a 3D model?

• Creating 3D models of objects mainly involves two methods:

photogrammetry and laser scanning. The methods can be used

separately or in combination.

• Laser scanning is best suited for work which requires a high

degree of precision across large surfaces.

• Photogrammetry is preferable for creating photorealistic models,

where precision across large surfaces is of no practical

importance.

Laser scanning - how does it work?

• Laser scanning uses a laser beam to measure the distance

between the measuring instrument and the object.

• It is a very precise process, even across large areas where the

properties of the camera lens makes photogrammetry less

precise.

• The visual representation of heavily textured surfaces such as

textiles is less realistic and visually appealing than when using

photogrammetry.

Photogrammetry - how does it work?

• When working photogrammetry, you take overlapping photos of

the object from various angles, until the entire surface of the object

is covered.

• These photos are then processed by software which identifies

shared points in the photos. Using these points as references, the

software then creates a 3D model.

• Commonly used softwares: RealityCapture and Agisoft Photoscan

(Metashape)

• The end results is a photorealistic model.

Pros and cons of laser scanning

• High precision even when dealing with large surfaces, like rock

carvings and buildings.

• Automated process where margins of error are down to the

capacity of the equipment. This reduces the risk of user errors.

• Quicker than photogrammetry.

• Expensive equipment, which quickly becomes obsolete.

• Unable to accurately reproduce textured surfaces.

Pros and cons of photogrammetry

• Cheap equipment – you can quickly get started using an ordinary

camera, tripod, and lamps.

• Upgrades are mainly in the form of new software, there is no need

for regular expensive hardware upgrades.

• Photorealistic and visually appealing models.

• A largely manual process, where a person’s knowledge and

experiences are crucial for the end result.

• Time consuming.

Do it yourself or hiring expertise?

• To create 3D models through photogrammetry, you need basic

knowledge of photography and the basic equipment needed for

object photography.

• You will also need suitable software and a gaming computer.

• If you haven’t done it before - expect a fair amount of time-

consuming trial and error when starting out, as all 3D objects

are unique.

• Make an agreement which clearly describes and regulates the

rights to all material that is being produced - regardless of

whether the work is done by your own staff or external

expertise.

Do it yourself – pros and cons

• All work is done on site – easy access to objects and control of the

full process.

• Easy to make changes based on new wishes and preferences

during the project.

• Low production capacity and inefficient workflow due to lack

of knowledge, experience, professional technical equipment,

hardware and software.

• Training staff requires time and resources.

Hiring external expertise – pros and cons

• High quality production and efficient workflow.

• Less risk and more efficient use of time and funds.

• You only pay for the time used for effective production of 3D

models, and not for training, testing, and solving of technical

problems.

• Less direct control of the process and limited opportunities

for making changes to an ongoing project.

• Objects are handled by other than staff.

Planning your work

• Start small with just one or a handful of objects. Evaluate the

results of the process before the next object is digitized and

published.

• What resources are currently available in the form of funding, time,

expertise, staff, and technical equipment? Will the project need

external resources to be carried out?

• Who is responsible for ensuring that the 3D model is published with

relevant information and metadata?

• Who is responsible for long-term maintenance and updating of

information, links, Wikipedia articles, communication on social

media?

For whom and why?

• For whom and why are the 3D models published? Will you reach

the target group(s) via your intended channels for publishing? By

social media? By the institution’s own website?

• Are the 3D models you have chosen relevant to the target

group(s)?

• Make the 3D model searchable and usable! Publish the model

with a descriptive text, metadata, and tags, as well as any

relevant links to more information on other sites.

• Should others be able to freely download, print, process, and reuse

the models (including for commercial purposes), for example in VR

and AP applications? If no – why?

If the 3D

models are

searchable,

anyone with

a computer

can access

them!

Examples of external platforms for 3D models - Sketchfab

• Sketchfab is the world’s biggest platform for publishing 3D models,

with millions of models and users. It is a commercial platform, but it

is free for museums and institutions to create a “Pro account”.

• You can upload your models directly from your software to

Sketchfab.

• Give your models detailed description and links to in-depth

information It is also possible to add annotations to details of the

model, and attach sound clips, supplementary photos, drawings,

maps etc. to the description.

• The models can be organized into categories and collections, and

be given tags for better searchability.

More examples of external platforms for 3D models

• Wikimedia Commons is a media archive consisting of images,

videos, audio clips, and other media files which promote knowledge

and education and which can be used, processed, and

disseminated for any purpose. Approved content for Wikimedia

Commons must have the potential to be used for educational

purposes.

• Currently, only 3D models in the .STL format can be uploaded to

Wikimedia Commons. This format does not support textures.

Models where a photorealistic surface is important to understanding

the object are not suitable for publishing in this format.

• There are also other platforms for publishing 3D models, like

Thingiverse and Scan the World.

A practical example – The Alunda Moose The Alunda

Moose

…is a Neolithic

ceremonial stone

axe, found at

Alunda, Sweden.

The Museum of

National Antiquity

(Historiska

museet) in

Stockholm used

photogrammetry to

make a 3D model

of it…

And published it on Sketchfab:

https://sketchfab.com/3d-models/the-alunda-elk-

8217e634da2e40258fe4db9a28cc4b36

I downloaded it, and let a 3D

printing company print it in

different materials and sizes

I sent one of

the models to a

stonemason,

and had him

handcraft a

copy from

stone

I made some

suggestions for

jewelry, for the

museum shop,

and checked

the sizes by

printing them in

plastic.

I did this

work

around

Christmas

time, and

suddenly

realized

that the

Alunda

moose

could be

used as a

candlestick

.

Use your 3D models creatively!

https://www.raa.se/in-english/outreach-and-

exhibitions/guide-for-publishing-3d-models/

Viktor Lindbäck

viktor.lindback@raa.se

+46 (0)8-5191 82 45

+46 (0)70-972 89 07