LightCap™

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LightCap™ is a new way to create both Materials or Matcap™ in real-time by manipulating directly the lights they simulate.

Using the LightCap Designer is simple and really powerful, even it is important to take in consideration that some difference exists between a Material and a Matcap, which have an impact on how you are using both with the LightCap:
A Matcap is a Material with light information backed in as an image, as soon as it is created, you can't change the light information in Matcap, while a Standard Material can be affected by the scene light. The LightCap Designer let you manipulate light information at creation time, but as soon as you change to another ZBrush project or restart ZBrush, you will not be able to change the Matcap light information. You can however individually save your LightCap in its own file format.
Also, another difference is the settings available for both Materials and Matcaps: Materials let you tweak and modify a large amount of settings and mix difference shaders together through the Shader Mixer, while a Matcap can be more globally manipulated through the textures in which it was composed of. Matcaps interact with the model geometry, mainly through the cavity information.
It's important to consider these points when creating a new Material or Matcap through the LightCap Designer.

• If you would like a material with advanced settings and abilities of tweaking, start with a standard Material like the Skin Shade 4 material.

• If you want a material with a great management of cavities and which will look similar depending of your scene, start with a Matcap.

Note: It is possible to use the Matcap information as a shader for the Standard Materials.Keep also in mind that using the LightCap Designer means modifying the current active Material or Matcap, then it means that the new lighting information will be mixed with the current material settings and you may need to alter them in order to achieve the result you are looking for.

Contents [hide] 1 LightCap workflow 2 LightCap and Matcap quality 3 LightCap with Environments 4 LightCap settings and options 4.1 Open and Save 4.2 Diffuse Channel 4.3 Specular Channel 4.4 LightCap preview 4.5 Sphere to Equirectangular mode 4.6 New Light 4.7 Delete Light 4.8 Light Index slider 4.9 Strength slider 4.10 Shadow slider 4.11 Aperture slider 4.12 Opacity slider 4.13 Falloff slider 4.14 Exposure slider 4.15 Gamma slider 4.16 Color Selector 4.17 Blend Mode 4.18 Texture (Txtr) selector 5 Alpha Selector 5.1 Horizontal Tile (HTile) and Vertical Tile (VTile) sliders 5.2 Scale Width and Height sliders 5.3 Blur slider 5.4 Orientation slider 5.5 Create Environment 6 LightCap adjustments 6.1 Exposure slider 6.2 Gamma Slider 6.3 Hue slider 6.4 Saturation slider 6.5 Intensity slider 6.6 Retain Highlight slider 6.7 Use material Curves mode 6.8 LightCap Horizon 6.9 Longitude and Latitude sliders 6.10 Horizon Opacity 6.11 C1 to C4 color selectors and sliders 6.12 Rate Top and Rate Bottom (Bot)

LightCap workflow

This is an example of workflow using the LightCap designer and may vary from your needs. LightCap with a Matcap or a Material:

• Load a ZBrush model or a Project.

• Select a Matcap, the default Red Wax one or a material like the SkinShade4. Both are great examples to use.

Note: This Matcap or Material will be definitely modified by the next steps and until restarting ZBrush. If you which to save your Matcap/Material editing with the LightCap Designer, you must save the Matcap/Material under a different file name or just save the LightCap information and load it if needed at a later stage.

• Change the default color to a white one if you have another selected, through the color selector located in the Color palette.

• Go into the Light palette and open the LightCap sub-palette.

• Click on the New Light button: it will add a new light in the preview window, creating a soft low light visible on a sphere. By clicking and dragging in this preview you will see a red dot appearing on the top of a sphere, this is the new light you just created. . Each time you add a light or move a light upon release of your cursor, your 3D model Matcap/Material will be updated.

• Now, change some light settings: increase the Aperture value to create a spread light. At the value of 180, it creates a light which is similar to the ambient light and fills the LightCap window with light. At times this is a good base light to start with for your material. Change the lights color by clicking in the color selector in the LightCap Designer. To finish with this step you can change the light Strength to create a stronger base light.

• It’s time to add an extra light, by clicking on the New light button: a new red dot appears as a new light projections onto the sphere. Like the two steps above, you can manipulate your lights and its setting as you go.

• When you are happy with the new light position, Color, Aperture or Falloff, click on the Specular button on the top right of the LightCap designer interface: now, you will be able to change the specular information of your Matcap/Material, mainly the opacity. The opacity setting is the only slider that is separate per channel for both Diffuse and Specular while others settings are connected between these two editing modes. It means that if you want to make a light invisible but keeping only its specular, you have to define the Diffuse opacity at 0 and the Specular opacity to a value higher than 0. If you change the Strength setting, both Diffuse and Specular will be affected.

Note: If your specular seems to be not affected by your color change and that you are using a standard Material like the SkinShade4, check the Material > Modifiers settings and in your Shader(s), that the Colorize Specular is at 0 and not another value.

• Continue the previous steps to create more lights and make your Material/Matcap visually richer.

• If your base material is a Matcap, go in the Material > Modifier sub-palette. You will notice at the bottom a little window with the image preview of both images created by the LightCap Designer if you used a Matcap at the beginning of this process. If you started with the RedWax Matcap you will have an image with two spheres. The sphere on the left (A) corresponds to the diffuse of the LightCap Designer and the one on the right (B), correspond to the specular of the LightCap Designer. Any modifier in the Matcap setting with A will affect the siffuse of the Matcap and any modeifier with B will affect the specular of the Matcap.

• If your base material is a Standard Material, in the Material > Modifier sub-palette. Try to modify the Ambient, Diffuse and Specular sliders: as you may have noticed, they are connected to the LightCap information, which means that if you want to see 100% of the LightCap Diffuse and Specular, you have to push the corresponding sliders to 100%. To conclude about the Standard Materials, remember that they are also connected to the default ZBrush lights, located in the Light palette: changing the light Intensity and position will have an impact to your scene preview and render. The default scene lights are simply added to the LightCap lights. The LightCap Designer system is an advance lighting system so if you wish to completely turn off the standard ZBrush light you can do so. Once the standard light is off only LightCap lights will affect the material.

LightCap and Matcap quality

When creating with LightCaps for a Matcap, ZBrush is internally using one or two images, for the channel A and B unless your start Matcap only has one sphere then only A channel is created. In this case the Diffuse and Specular of LightCaps is baked together into the one sphere. The quality of these image is based on the Render > Render Properties > Details slider. A value of 1 means a 512x512 internal map, a value of 2 means a 1024x1024 internal map and a value of 3 means a 2048x2048 internal map.
By having a higher render quality, you will increase the details of these internal maps, which can be visible when using a texture or an alpha for your LightCap lights. Depending on your needs, use this setting to increase or decrease the quality of the internal maps. When this detail slider is changed the internal maps will automatically update when a light is clicked in the LightCap Designer.
Note: It is important to consider the memory aspect of the Render Details, setting a larger map size will require more memory and more computing. If your LightCap doesn’t include details with Alpha and texture maps, we recommend using the lowest quality.

LightCap with Environments

A LightCap can be creating directly from the background texture that is loaded into the Background sub-palette. By analyzing the background’s high and low intensity values and their colors, lights will automatically be created at correct positions and accurate intensity of lights with shadows turn on for lights above the horizon line. This one click operation can create most if not all of your lights ready to be edited in the LightCap Designer system. Please read the Background section for more information about creating a LightCap from a background image.

An example of a Background image used to create a LightCap.


The opposite is also possible with LightCaps: ZBrush can generate a background image from all lights and color that are on in the LightCap Designer. LightCap will store all the lighting information based on a sphere, it is easy to project this information as a background image, which then, will fit the look and feel of your model with its Matcap or Material assigned to it from that was created from the LightCap Designer system. To create an environment from the LigthCaps, simply click on the Light > LightCap > Create Environment button. After a few seconds, your background image will be replaced by a new image based on the LightCap information.
This background image can only be saved within a Project and can't be exported as a separate image.

LightCap settings and options

The LightCap sub palette, located in the Light palette.

Open and Save

The Save button lets you save a LightCap and all its information and the Open button allows you load a previously saved LightCap.

Diffuse Channel

Swtich to this channel in order to manipulate the lights that will affect the diffuse of any material. Any changes done to the lights settings will be linked to the Diffuse slider of a Standard Material and will be linked to the A channel (or the left sphere) of a Matcap.
Note: Except for the Opacity information, all your changes in values and settings will be also applied in the Specular mode.

Specular Channel

Swtich to this channel in order to manipulate the lights that will affect the specular of any material. Any changes done to the lights settings will be linked to the Speculat slider of a Standard Material and will be linked to the B channel (or the right sphere if the RedWax was originally selected.) of a Matcap. If you did not select a Matcap with two spheres then the specular will be baked into the A channel along with the diffuse light information.

LightCap preview

The preview window displays the preview of the LightCaps in real-time, will also allow you to manipulate the light by moving their dots corresponding to their positions. The Preview display can be switched to diffuse information or the Specular information of the LightCap. A red dot corresponds to the current light while grey dots correspond to non-selected lights. The default preview is display as a sphere, which correspond to a 360° light positioning system and not 180°, which mean that lights which are positioned on the side of the sphere are in fact lighting the back of your model and not its side. If you wish to light the side, you must approximate your light position.

Sphere to Equirectangular mode

The LightCap can be display as a sphere (by default) and in a planar form name Equirectangular, similar to environment map with a width to high ratio of 2:1.
To change the preview of the LightCap, click on the larger red dot on the top left corner of the LightCap preview, visible only when hovering your cursor in the top left corner of the LightCap Preview window. To turn the LightCap Preview to the default view click on the top left corner again.

On the left, the Spherical projection, on the right, the Equirectangular projection.

New Light

The New Light button adds a new light with its default setting on the center of the LightCap preview.

Delete Light

The Delete Light button deletes the active light of the LightCap preview.

Light Index slider

The Light Index slider lets you quickly select the lights in order of creation by moving the slider or clicking on the arrow buttons on the left and right of the slider.

Strength slider

The Strength slider defines the diffuse and specular intensity which are bound together.

Shadow slider

The Shadow slider defines the opacity of the shadow generated by the LightCap light and if the light will even cast shadows. To completely turn off shadow casting of any individual light move this slider to 0.
When a LightCap is generated by from the environment background, the shadow intensity may vary and most of the time, the light under the horizon line have their intensity at 0.

Aperture slider

The Aperture slider defines how the light or its specular spread falls over the surface. A high value will spread the light on the surface while a low value will do the opposite, creating a very concentrated light.
Note: We recommend the first light created in the LightCap, have an Aperture value of 180 which will create a kind of base light with any selected color, which will be similar to an ambient light.

Opacity slider

The Opacity slider changes the selected light’s opacity. This setting is different from the Strength because it doesn't affect this value, but makes it more or less transparent. The Opacity value can be different for the Diffuse and Specular mode of the LightCap: you can create a light which won't have a diffuse impact, but which will have only affect specular by turning the Opacity slider all the way to 0 on the diffuse channel but keep it at 1 in the specular channel or you can apply the opposite effect.

Falloff slider

The Falloff slider defines the distance that the light will cover over a model from it center point to its extremities. The falloff doesn't affect the amount of light or specular, but how it is distributed on its aperture space.

Exposure slider

The Exposure slider lets you apply a multiplier on the light Strength value. This is very similar to the Exposure in photography.

Gamma slider

The Gamma sliders allows you to change the Gamma of the light, which mainly affects the contrast of the light color.

Color Selector

The Color selector allows you to define the color of your light. As each color picker in ZBrush, you can click in the color selector and drag your cursor any where in ZBrush’s interface to pick a color. With the LightCap, only the real color will be picked and not the color combined with the shadow and specular information.

Blend Mode

The Blend mode affects the way the current light will overlay with other existing light of the LightCap. ZBrush offers various kind of blending modes, similar to the ones found in popular 2D software.

Texture (Txtr) selector

By clicking on the Txtr button, the Texture palette will appears, allowing you select a texture to be applied to the light itself as a gel image which will be projected on the LightCap.
Note: If you want to use your own textures, you must first load it through the Texture palette or by clicking on the Import button in the Texture floating window.

Alpha Selector

The Alpha selector button is similar to the Texture selector except that it allows you load an Alpha which will define the shape of the light. Like this, you can create light shape similar to what you can find in photography studio with rectangular soft box and a gobo lights that are used in film.
Note: If you want to use your own alphas, you must first load it through the Alpha palette or by clicking on the Import button in the Texture floating window.

Horizontal Tile (HTile) and Vertical Tile (VTile) sliders

Both Horizontal and vertical tile sliders allow you to change the number of and selected Texture and/or Alpha being applied in both horizontal and vertical axis.

Scale Width and Height sliders

Both Scale Width and Height sliders allow you to adjust the size of any selected Texture and/or Alpha in both horizontal and vertical axis.

Blur slider

The Blur slider allows you apply a blur on the loaded Alpha and Texture of the selected light.

Orientation slider

The orientation slider allows you to change the rotation of the Texture and/or Alpha applied to the selected light.

Create Environment

The Create Environment utility converts the LightCap into a background texture that is automatically loaded as a background in the Light > Background sub-palette.
Note: For more information about the background and the LightCap please read the LightCap and Environment chapter of this LightCap section.

LightCap adjustments

The LightCap Adjustment sub-palette includes several functions, which will globally alter or transform the current LightCap in opposition to the LightCap settings, which will only affect the selected light.

Exposure slider

The Exposure slider allows you to apply a multiplier on all the light intensities of the LighCap. This is very similar to the Exposure in photography.

Gamma Slider

The Gamma sliders allows you to change the Gamma of the LightCap, which affects the contrast of the light color.

Hue slider

The Hue slider allows you to change the global hue of the LightCap, which can let you alter its global color tint.

Saturation slider

The Saturation slider allows you to change the color quantity of your LightCap. A low saturation will make the color lean more to the grayscale while a high value will increase the color saturation of the LightCap

Intensity slider

The intensity slider allows you to increase or decrease globally the color intensity. In opposition to the Exposure which alters mainly the lights exposure, the Intensity affects all the LightCap in the same way, whether it's just a color or a light.

Retain Highlight slider

The Retain Highlight slider allows you to decide which part of the specular highlight you want to make visible or not, mainly to change the lights highlight.

Use material Curves mode

By enabling the Use Material Curve mode, you can use the Standard Material shaders Diffuse and Specular curve to modulate the diffuse and specular information.

LightCap Horizon

The LightCap horizon sub-palette includes functions to manipulate the orientation of the LightCap, but also creating and manipulating a Horizon Line.

Longitude and Latitude sliders

The Longitude and Latitude sliders allow you to rotate your LightCap on both horizontal and vertical axis. This is a great and quick way to change the global light and color orientation of your LightCap, letting you create variations in just a few clicks.

Horizon Opacity

The Horizon opacity slider displays the horizon line which is composed of two gradients above and below the median line. The slider value sets its visibility.

C1 to C4 color selectors and sliders

The C1 to C4 sliders and color selectors define the start and end color of the bottom to top gradient of the horizon line along with the corresponding color intensity.

Rate Top and Rate Bottom (Bot)

The Top and Bottom Rate sliders define the offset of the gradient of both bottom and top horizon.

 

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