DriveWorks Pro 24

PBR

PBR - Render Property

PBR (Physically based rendering) will render appearances based on real world material properties.

With PBR visually realistic results are possible under all lighting conditions.

Most modern game engines and content creation tools support PBR materials because they are considered the best approximation of real world scenarios for real-time rendering.

PBR Example - Brushed Steel	PBR Example - Brick

Setting up an Appearance to use the PBR render property

1. In a DriveWorks 3D Document, navigate to and select an Appearance.
2. In the Information Panel select the Render Properties drop down.
3. Select PBR from the drop down list.
4. Select the Alpha Mode required for images applied to the PBR Advanced render property.

   Alpha Mode allows images with transparency to display any objects or scenes behind them.

   See Alpha Mode below for more information.

Alpha Mode

Alpha Mode allows images with transparency to display any objects or scenes behind them.

For Render Properties, other than Glass, the Alpha Mode can be set to:

• Default

  Will display any alpha in the image as fully visible.

• Cutout

  Will display any alpha in the image as fully visible or fully transparent, depending on the Cutout Threshold.

  • Cutout Threshold

    Set a value between 0 and 255 for the threshold to use to determine the pixels that will be displayed.

Using images with transparency, with the Cutout Alpha Mode, can enhance the DriveWorks 3D model by reducing the need for complex geometry.

For example, the image below:

Can be applied, as an appearance, to a Model.

The gray and white chequered background represents the alpha channel used in the image.

The Alpha Mode settings applied are shown in the table below:

Default	Cutout

Render Property Settings

The settings available on the PBR Advanced render property are grouped into the following categories:

Albedo settings

Albedo sets the color to use for the appearance and will factor in the reflection color when a material is metallic.

When a Diffuse Texture is applied the RGB values will tint the diffuse texture.

Values applied to the Red, Green, Blue and Alpha parameters will set the color for the albedo of the Appearance.

Will apply a hexadecimal value to Albedo in the Parameter Panel.

• Red

  Modifies the amount of red in the Diffuse Color. Enter a number from 0 to 255.

• Blue

  Modifies the amount of blue in the Diffuse Color. Enter a number from 0 to 255.

• Green

  Modifies the amount of green in the Diffuse Color. Enter a number from 0 to 255.

• Alpha

  Controls the alpha channel or transparency of the Diffuse Color. Enter a number from 0 to 255.

  If the geometry with the Albedo applied is to have Shadow Casting or Edge Sketch applied, the appearance is required to be fully opaque.

  The alpha applied needs to be exactly 255. Anything less than this value is considered not fully opaque.

Albedo also includes properties that describe the surface of the material:

• Roughness

  Low values appear shiny or glossy, high values appear rough or matte.

  When a Roughness Texture is applied this value will multiply the roughness in the texture image (0.5 will decrease the roughness by 50%).

• Metallic

  Metallic makes the albedo factor in the reflection color.

  This setting reduces the brightness of the diffuse lighting component and increases the specular (as metals reflect a lot more light rather than absorb or scatter it).

  When a Metallic Texture is applied this value will multiply the metallicness in the texture image (0.5 will decrease the metallicness by 50%).

• Ambient Occlusion

  Ambient Occlusion is the brightness of the lighting from the environment map, both the image-based ambient and the reflection.

  When a Ambient Occlusion Texture is applied this value will multiply the ambient occlusion in the texture image (0.5 will decrease the ambient by 50%).

Texture Offset settings

• Offset X

  Offset an applied texture in the X Axis. Allows you to position textures accurately on surfaces. Enter a number.

• Offset Y

  Offset an applied texture in the Y Axis. Allows you to position textures accurately on surfaces. Enter a number.

Texture Transforms settings

• Scale X

  Modifies the scale of a texture to suit the size of the model.

  Enter a number from 0 and above.

  See Scaling Textures below for information on how scaling affects the applied texture image.

• Scale Y

  Modifies the scale of a texture to suit the size of the model.

  Enter a number from 0 and above.

  See Scaling Textures below for information on how scaling affects the applied texture image.

• Angle

  Change the rotation of a texture on a model. Enter a number from 0 to 360.

Scaling Textures

The scale of a texture is applied differently when World Position Textures is enabled.

• When World Position Textures is Disabled:

  A scale of 0.5 will stretch or shrink half of a texture repetition over the corresponding axis of the geometry it is applied to.

  A scale of 1 will stretch or shrink one full texture repetition over the corresponding axis of the geometry it is applied to.

  A scale of 2 will stretch or shrink two full texture repetition over the corresponding axis of the geometry it is applied to.

  For example:

  Geometry Scale in the X and Y axis = 0.5 (meters)

  Texture Transform Scale X and Y axis = 1

  Will result in one full texture repetition over the 0.5 meter of the X and Y axis.

  

• When World Position Textures is Enabled:

  A scale of 0.5 will apply half of a texture repetition over a 1 meter length in the corresponding axis.

  A scale of 1 will apply one full texture repetition over a 1 meter length in the corresponding axis.

  A scale of 2 will apply two full texture repetition over a 1 meter length in the corresponding axis.

  For example:

  Geometry Scale in the X and Y axis = 0.5 (meters)

  Texture Transform Scale X and Y axis = 1

  Will result in half a full texture repetition over the 0.5 meter of the X and Y axis.

  

World Position Textures

World Position textures allow seamless texturing over multiple models.

To understand how a World Position Texture is scaled see Texture Transforms settings above.

World Position Textures Disabled	World Position Textures Enabled
The same textured appearance applied to multiple geometries does not flow seamlessly when one of the geometries differs in size.	Enabling World Position Textures allows the same texture to flow into geometries with a different size without the need for complex calculations to scale the texture.

The following parameters can be selected:

Checking each checkbox will add that world position axis value at each pixel's location, to the corresponding texture coordinate value.

This has the effect of making the texture flow along that axis in world space.

• Enabled

  Checking this will enable World Position Textures.

  A rule can also be built for this from the parameter panel by selecting the Enabled (with the address WorldPositionEnabled) property.

• Horizontal
  • X

    Checked by default

    Check to add the horizontal X axis to the corresponding texture coordinate value.

  • Y

    Unchecked by default

    Check to add the horizontal Y axis to the corresponding texture coordinate value.

  • Z

    Checked by default

    Check to add the horizontal Z axis to the corresponding texture coordinate value.

• Vertical
  • X

    Unchecked by default

    Check to add the vertical X axis to the corresponding texture coordinate value.

  • Y

    Checked by default

    Check to add the vertical Y axis to the corresponding texture coordinate value.

  • Z

    Unchecked by default

    Check to add the vertical Z axis to the corresponding texture coordinate value.

Diffuse Texture

• Texture

  Select a diffuse texture from the list of available textures in the Document. Alternatively you can browse for a texture or build a rule to the path of a new texture.

Roughness Texture

• Texture

  Select a roughness texture from the list of available textures in the Document. Alternatively you can browse for a texture or build a rule to the path of a new texture.

Normal Texture

• Texture

  Select a normal texture from the list of available textures in the Document. Alternatively you can browse for a texture or build a rule to the path of a new texture.

Metallic Texture

• Texture

  Select a metallic texture from the list of available textures in the Document. Alternatively you can browse for a texture or build a rule to the path of a new texture.

Ambient Occlusion Texture

• Texture

  Select an ambient occlusion texture from the list of available textures in the Document. Alternatively you can browse for a texture or build a rule to the path of a new texture.

Using the PBR render property

Real world material appearances are best achieved by applying PBR texture images.

Many online resources offer free PBR texture downloads such as Poly Haven, Textures.com, Free PBR and cgbookcase.com.

The files downloaded from these sites will include various image files.

These will be suffixed with a name that corresponds to the following Texture properties:

• Diffuse Texture - use the file suffixed with _BaseColor or _Albedo or similar
• Roughness Texture - use the file suffixed with _Roughness or _NormRough or similar
• Normal Texture - use the file suffixed with _Normal
• Metallic Texture - use the file suffixed with _Metallic (will only be supplied for metallic materials)
• Ambient Occlusion Texture - use the file suffixed with _ao or _ambient or similar (not always supplied)

The lighting model, of the PBR render property, relies heavily on having an Environment Map applied to display realistic reflections.

Using a HDRI image will give the best results.

Once the images have been applied, finer adjustments can be made to the appearance using the properties found in the Albedo, Texture Offset and Texture Transforms groups of settings.

PBR Example - Painted Steel	PBR Example - Wood

Other Render Properties

DriveWorks has other render properties available to use on an Appearance.

These add different levels of realism to an Appearance.

• Default
• Specular
• Bump
• Emissive Bump
• Reflective
• Glass
• PBR Advanced