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Welcome to the official Light Painter documentation! Here you can learn how to use the Blender add-on and dive into the Python package.

The painting is done within each tool. Once installed, you can find these tools on the left-hand side of the 3D view in the toolshelf (T it the default shortcut to hide/reveal this shelf). Buttons with a small triangle in their bottom right corner are tool groups, which can be opened by holding LMB on them for a moment (or dragging LMB to open the group instantly).

When the tool is selected, left-click the mouse to start the tool. From there, you can use the mouse left-click and right-click to draw and erase marks on surfaces respectively. Press Escape key to cancel, and the Return/Enter key to add light.

Now just paint where you want the light to hit your objects' surfaces!

You do not need to fill in every surface. Draw some simple strokes over surfaces that you would like highlighted by your light. Keep in mind that the surface's normal you are drawing over can influence where the light will be finally positioned.

The tool also works best when your strokes matches the shape of the type of lamp that you want. If you hold down either Alt key, it allows artists to draw straight lines. It will remember the last point drawn and show a faint line where the straight line will go. With this, you can draw geometric shapes.

Here are some general painting tips:

• Draw on multiple surfaces. The operators can handle most cases where surfaces face different directions, but it will fail if the average of the surface direction is zero.
• Spot lamps prefer circular strokes. But if you do not trust your drawing ability, a painted line representing the diameter is sufficient.
• Area lamps prefer rectangles, squares, circles or a single painted line.
• Point lamps are the most forgiving since a point lamp's rotation is irrelevant to its ability to light.

You can choose between the main light types (for the sun lamp, see "Sky Paint"):

• point lamp
• spot lamp
• area lamp

Like with any of the tools, you can press F9 or click the collapsed Redo Panel in the bottom-left corner of the 3D view to tweak parameters, such as:

• Light color.
• Light distance and power. For lamp objects, a "Relative" toggle is available. When enabled, this allows you to adjust light coverage and falloff by adjust the lamp distance, without affecting apparent brightness.
• Ray visibility settings, to tweak light or object visibility for diffuse, specular, or volumetric rays or shaders. Note that these ray visibility settings will be dependent on your render engine's implementation, as Eevee and Cycles handle visibility differently or may ignore it.

This is a separate tool where the modal adjusts the currently active lamp instead of adding a new one. You can find this tool, with a purple lamp icon, right below the add light tool group.

You can also create mesh lights. Note that they use emissive materials, which may not behave the same in all render engines. They have similar parameters as the lamp tool, along with a few extra.

Mesh lights create a convex shape from the strokes you drew. This tool has an extra parameter to flatten the hull into a plane.

Tube lights turn each stroke into a "tube" of light - great for neon lighting. This tool has extra parameters to merge tube vertices by distance (for a smoother tube shape), and subdivisions for the tube path or its resulting surface.

You can add either a sun lamp or a sky texture.

There are two options to determine direction: "average" - which just takes the mean normal of the annotations, like all the other Light Painter tools - and "occlusion". The latter imitates a sun above the horizon. For the number of samples given, the operator will iterate over different sun positions and check how much of your strokes will be lit from that angle. After iterating over all the samples, the operator will choose the best position based on how closely it matches the average normal and the percentage of your strokes hit.

However, this scoring may result in noonday lighting from above. To give you more control, there is a "Max Sun Elevation" parameter where you can specify the max elevation of the sun. This can force the operator to only sample the sun at lower elevations, giving more dynamic lighting.

Flags can be painted to cast shadows on surfaces. Note: you must select lamps to flag before running the tool. It takes the surfaces drawn and generates makes a convex mesh hull to block the light. Parameters can be changed such as position, the flag's color (for bounce lighting) and opacity.

1. First, add the lights.
2. Select the lights you want to flag.
3. Run the Flag Paint tool. Paint surfaces you want darkened. These annotations will be considered edges of a convex hull.
4. Finish the tool by pressing Enter. This will add a flag for each light.

Currently, flags for sky textures are not supported.

Quickly add procedural textures to point and spot lamps. Since this uses Cycles nodes, it is only supported in Cycles. You can find this panel in your active lamp's properties. You can choose between the different procedural texture types available within Blender.