New BPR Filters

From ZBrush Info

ZBrush 4R2b introduces new BPR Filters, located in the Render >> BPR Filters sub-palette. These new settings bring new real-time effects to your rendering. They allow you to create high quality images by compositing more and more filters as a post-render effect. This means you do not need to perform render after render as you try new things.

These filters work the same way you’re already familiar with from ZBrush4R2. If you are unfamiliar with them please read the BPR Filters page.

The BPR Filters now have 12 slots which can each host a single filter. This allows you to create thousands of advanced render effects simply by combining up to twelve individual filters. You can also put the same filter in multiple slots with different settings.

New Filters

The list below details the new filters added in this ZBrush release:

• Negative: With the color patch set to mid-grey and a strength setting close to 1, this filter adjusts your render to look more like a film negative.
• Gamma: Applies an exponential of the color intensity. It lightens the overall image without washing out detail.
• Additive: Offsets all colors in the image to be brighter or darker by an equal amount.
• Paint: Applies the selected color from the patch over the BPR render. Combined with the Mask and Fresnel settings, it can produce non-photorealistic rendering (NPR).
• Contrast User Color: Allows you to modulate the contrast of the render using the Color information defined with the color patch available below the Strength slider. This color will be added with the colors from the final render. A darker color will create a much more contrasted render and lighter color will provide less contrast.

For better results you can mix this contrast with the Mask modulator.

• Contrast Auto Color: Similar to the Contrast User Color, but ZBrush will find the best color from the final render.
• Contrast Auto Gray: Similar to the Contrast User Color, but the contrast will use a neutral grey. This results in a neutral colored contrast.

BPR Filters Operators

In addition to the new filters, ZBrush 4R2b introduces new Operators which are able to mix your BPR filters togethers.

• Red, Green and Blue Components: Display only the red, blue or green component channels of the image.
• Depth Slider: Use this slider to determine how strong the filters are applied relative to the depth of each pixel within the rendered image.
• Depth A and B: These sliders modulate the Depth operator to let you define the starting and ending point of the render depth. Depth A defines where the filter will begin to affect the image with a slow exponent and Depth B represents where the filter will be applied at 100% intensity.

Note:These slider values are easily set simply by clicking one and then dragging your cursor over your render to pick a point in the image that has the desired A or B depth value.

• Depth Exponent: This controls falloff between Depth A and Depth B. The higher the value the more harsh the transition will be from Depth A to Depth B. Lower values will have a slow, soft transition.
• Cavity: Applies the current filter to the portions of the render detected as being surface cavities. This is similar to the way a MatCap can use cavities to display two different shaders. The Cavity filter can be modulated by the cavity radius detection and sensibility detection, which can drastically change the transition across the surface’s geometry.

The evolution of a BPR Filters render, from top left to bottom right: The original render, a paint-over modulated by a Fresnel setting, followed with Contrast by User Color, then Cavity detection and finally, a Sharpen Filter. Image courtesy of Ryan Kingslien.