Introduction to PBR

A guide to PBR implementation in Browzwear tools

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Background 2

Advantages of PBR 2

Material Structure in Browzwear 3

Layer Types 4
Diffuse 4
Specular 5
Roughness 6
Specular Tint 7
Normal 8
Metalness 9
Displacement 10
Sheen 12
Sheen Tint 13
Subsurface 14
Clear Coat 15
Clear Coat Roughness 16

Automatic Conversion to PBR 17

Working with Vizoo and xTex 18

Exporting 3D Objects 18

References 18
Introduction to PBR

Background
Physically Based Rendering (PBR) is a method of shading and rendering that
provides an accurate representation of how light interacts with surfaces. PBR is
widely adopted in many 3D applications, including game engines and file sharing
platforms. It’s already considered a material standard - one which 3D artists should
take into account in their creation processes.
In Browzwear, PBR is active from the moment the software is loaded. It’s not a
function that the user needs to activate, and PBR cannot be switched off.
The previous shading model Browzwear used is called Phong shading. In addition,
there are several other shading models, none of which are physically based,
available on software such as Maya and 3ds Max. In Browzwear, however, only PBR
is used.
A 3D object imported to Browzwear that has been assigned non PBR material is
automatically converted to PBR. There are a few discrepancies that might occur
during that process, possibly leading to inaccurate display. For more information
about this, refer to A
​ utomatic Conversion to PBR​.

Advantages of PBR
● Realistic representation of materials
● Consistent display of materials - maintains material familiarization between
different users with different lighting settings
● Easier adjustments to get the desired look - less guess work
● Allows more creativity in the material creation process
● U3M support - the new standard for material capturing, authoring and
sharing developed by Vizoo
● Aligned with Substance Designer texture output - the most advanced
procedural material authoring tool

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Introduction to PBR

Material Structure in Browzwear

The material is made of layers. Each layer defines a specific surface behavioral
response to light.
Most of the layers consist of an image (texture) and an intensity slider.
Intensity sliders behaviour:
● All the intensity sliders range from 0 to 1 except specular intensity. For more
information about specular intensity, refer to ​Specular​.

● When loading a map into a layer, the intensity slider is automatically set to a
value of 1.

● Intensities can be adjusted without using a map:

○ A value of 1 is similar to a solid white colored map.

○ A value of 0 is similar to a solid black colored map.

○ A value ranging from 0 to 1 defines a grayscale level.

● Adjusting intensities when using a map:

○ A value of 1 means that the map is fully in use.

○ A value of 0 means that the map is not in use and instead a black
color is in use.

○ A value ranging from 0 to 1 defines the blending level of the map with
the color black.

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Introduction to PBR

Layer Types
The following list of layers is implemented for PBR in Browzwear. The most
important layers that are most likely to have a dedicated image map are ​diffuse​,
specular​, r​ oughness​, and ​normal​.

Diffuse
[Map + color + color blending modes]
● Responsible for the most noticeable surface characteristics.
● In Browzwear, material must have a diffuse map.

Diffuse map and diffuse color: #66afba (RGB:188,45,73)

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Introduction to PBR

Specular
[Map + intensity slider]
● Defines the amount of light being reflected from a surface.

● Reflection level is defined by the brightness level of each pixel. heu and
saturation are ignored.

● Specular together with roughness defines how shiny the surface is.

● If no map is in use, it is recommended to set the specular intensity to 0.5.

Specular intensity: 1 and roughness: 1

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Introduction to PBR

Roughness
[Map + intensity slider]
● Defines the smoothness/roughness of a surface usually derived from its level
of imperfections or graininess. If a surface is smooth like plastic it has a low
roughness value, and if a surface is rugged and grainy like fabric it has a high
roughness value.

● Using roughness maps instead of specular maps can contribute to a

smoother workflow, preventing the guesswork in the material preparation or
adjustments. The specular intensity should be set with the desired amount of
reflectivity using the intensity slider and the roughness map determines the
microsurface behavior. If the result is too rough and not shiny enough, there
is an option to lower the roughness intensity value from 1 to around 0.8.

Specular intensity: 1 and roughness: 0.5

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Introduction to PBR

Specular Tint
[Intensity slider]
● Defines the amount of diffuse color presented on the shiny areas.

● A value of 0 means no blending with diffuse color and only the light source
defines the reflected color.

● A value of 1 recolors the shiny areas with the diffuse color.

Specular intensity: 1 and roughness: 0.5 and specular tint: 1

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Introduction to PBR

Normal
[Map + depth slider]
● Expose subtle 3D characteristics of a surface.

● Depth slider ranges from -3 to 3. The negative values invert the height
definition embedded in the normal map.

● Normal maps can be generated with 3D software like Maya, 3ds Max, Modo,
and so on, or by 2D software like Photoshop, Xnormal, and Crazy Bump.

Normal depth: 0 Normal depth: 1.5

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Introduction to PBR

Metalness
[Map + intensity slider]
● Defines whether the surface is metallic or not

● Metals reflect light in a different way than other materials. Metalness

provides a built-in behavior that mimics the way light is projected back from
metallic surfaces.

● Although it was setup to properly display metals, it can be used for satin or
silky fabrics as well.

Metalness intensity: 1 and roughness: 0.5

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Introduction to PBR

Displacement
[Map + intensity]
● Adds 3D characteristics by extruding 3D geometry based on an image.

● The white color defines maximum extrusion strength going outwards.

● Black color defines maximum extrusion strength going backward, creating

indents on the fabric surface. The fabric indentation effect can be achieved
only when Enhanced Layer Blending is turned on.

● Medium gray (rgb=128) has no effect.

● Displacement maps are very useful to generate a more realistic 3D effect for
different artwork print techniques.

● The displacement effect is only visible in ray trace rendering.

Displacement map on fabric Displacement value: 0.1cm

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Introduction to PBR

Displacement map on artwork Displacement value: 0.3cm

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Introduction to PBR

Sheen
[Intensity]
● Defines the behavior of light reflected from the outskirts of an object.

● It helps to visualize the natural fuzziness of fabrics by adding shininess near

the edges of 3D objects.

Sheen intensity: 1

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Introduction to PBR

Sheen Tint
[Intensity]
● Defines the amount of diffuse color that would be presented on the shiny
areas defined by sheen.

● The value of 0 means no blending with diffuse color and only the light source
defines the reflected color. A value of 1 recolors the shiny areas with the
diffuse color.

Sheen intensity: 1 and sheen tint: 1

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Introduction to PBR

Subsurface
[Map + color + intensity]
● Defines another base layer like diffuse.

● Widely used in computer graphics to visualize complex materials such as

human skin.

● It can be used in apparel to visualize special fabrics or artworks in which the

reflected colors are different from the diffuse color. This is achieved by
setting the specular tint to 1 (recoloring the shiny areas with the diffuse
color) and setting the subsurface color to be different from the diffuse color.

Subsurface color: #b143d9 (RGB:177,67,217) and subsurface intensity: 0.85

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Introduction to PBR

Clear Coat
[Intensity]
● Adds another layer of shininess.

● Useful for 3D trims; for example, a rough button with a coating applied. It can
also be used for leather material or twill wax fabric.

Clear coat intensity: 1

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Introduction to PBR

Clear Coat Roughness

[Intensity]
● Defines the clarity level of the clear coat layer.

Clear coat intensity = 1 and clear coat roughness = 0.25

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Introduction to PBR

Automatic Conversion to PBR

PBR was introduced in VStitcher and Lotta April Edition 2019 as the only shading
model available, thus causing older files to be automatically translated to PBR once
opened in Lotta/VStitcher April Edition 2019 and newer versions.
In the automatic translation process, the specular and roughness values are
calculated to best match the 3D appearance of the garment as it was previously
shown.
Correct intensity values for PBR should range from 0 to 1 (except the normal
channel). The Browzwear implementation of PBR shows a specular intensity that
can go up to a value of 10. This extra range was added to allow a successful
automatic translation without the need for further manual work to be done.
Sometimes automatic conversion may not produce the best results, especially for
highly reflective materials. The following list covers the display issues that may
occur and how to resolve them:
● Fabric is too shiny (over exposed):
a. Increase the roughness intensity or brighten the roughness map
b. Decrease the specular intensity or darken the specular map

● Fabric is not shiny enough (looks pale):

a. Decrease the roughness value or darken the roughness map
b. Increase the specular value or brighten the specular map

● If you notice a general regression with the fabric appearance, consider

converting the specular map to a roughness map. The process to manually
do that is as follows:
a. Load the specular map into Photoshop (edit externally)
b. In Photoshop go to the Main menu > Image > Adjust > Invert
c. Save the new image on the desktop
d. Load the new image into the roughness map
e. Remove the specular map
f. Set specular intensity to 0.5

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Introduction to PBR

Working with Vizoo and xTex

To get the best out of PBR we strongly recommend you scan the fabrics with a
Vizoo scanner and prepare the textures using its xTex software. Make sure to
output a PBR ready material and use 8bit images.

Exporting 3D Objects
FBX and OBJ formats are the optional 3D export formats in Browzwear. Both
formats are not compatible with PBR information, which is why Browzwear
developed a modified version of FBX that carries the correct PBR data. The PBR
data consists of the different materials in use and the textures involved but without
connecting the textures to the materials. The connection should be done on the
destination software.

References
A Comprehensive PBR guide by Allegorithmic
https://academy.substance3d.com/courses/the-pbr-guide-part-1
https://academy.substance3d.com/courses/the-pbr-guide-part-2

Understanding PBR - Video tutorial

https://www.youtube.com/watch?v=ueC2qGzWrgQ

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