3D painting

You can use any Photoshop painting tools to paint directly on a 3D model just as you would on a 2D layer. Use selection tools to target specific model areas or let Photoshop identify and highlight paintable areas. 3D menu commands let you clear away areas of a model to access interior or hidden portions for painting.

When painting directly on the model, you can choose which underlying texture map to apply paint to. Typically paint is applied to the diffuse texture map, which gives a model material its color properties. You can also paint on other texture maps, such as the bump map or opacity map. If you paint on an area of the model that lacks the type of texture map you’re painting on, a texture map is automatically created.

Different painting methods are appropriate for different use cases. Photoshop provides the following 3D painting methods:

Live 3D Painting: (Default in Photoshop) Brush strokes made in the 3D model view or the texture view are reflected in real time in the other view. This 3D painting method offers high performance and minimum distortion.

Layer Projection Painting: The Gradient tool and filters use this painting method. The Layer Projection Painting method involves merging a painted layer with the underlying 3D layer. During the merge operation, Photoshop automatically projects the paint onto the appropriate target textures.

Projection Painting: (Default in Photoshop Extended CS6) Projection Painting is suitable for painting multiple textures simultaneously or for painting the seam between two textures. However, in general, it is a lower-performance painting method and may result in cracks when you’re painting complex 3D objects.

Texture Painting: You can open the 2D texture and paint it directly.

Some tips to paint 3D models

• If the model area is hidden, you can temporarily cut away surface areas that are blocking your view. See Reveal surfaces to paint on.
• If you are painting on curved or irregular surfaces, you can get visual feedback before you paint of which areas can best receive paint. See Identify paintable areas. You can also set the paint fall-off angle, which controls the amount of paint applied to angled surfaces. See Set the paint falloff angle.
• While painting texture seams, a single brush stamp applies only to one side of the seam. Move the center of the brush across the seam to paint its other side.

• If you try to paint on a texture map type that the material doesn’t contain, Photoshop prompts you to create a map. For information on map types, see 3D Materials settings (Photoshop Extended).

Paint an object in the Live 3D Painting mode

1. Open the 3D model in the 3D model view.
2. Open the texture document that you want to paint. To do so, double-click the name of the texture in the Layers panel.
3. Select Window > Arrange > Tile to view the 3D model view and the texture document side by side.
4. Using the Brush tool, paint the 3D model or the texture document. Your brush stokes reflect automatically in the other view.
   

Switch to the Projection Painting mode

1. Create or open a 3D model.
2. Select 3D > Use Projection Painting.
3. Paint your 3D model.
   

Unwrap UVs of a 3D model

Photoshop provides an option to automatically unwrap UV maps for your 3D model.

1. Open the 3D model.
2. Select 3D > Generate UVs.
3. The warning When using Generate UVs, all of the meshes' materials' textures will be flattened is displayed. Click OK to continue.
4. In the Generate UVs dialog box that appears, choose the following material and unwrapping options:
   

If multiple maps—for example, Diffuse and Bump maps—exist on a single mesh, combine them into one map.

Example: Combine two different Diffuse maps into one Diffuse map.

If you have multiple meshes, each of them will still have their own map. For example, if you have three separate meshes with three Diffuse maps, you'll still have three separate Diffuse maps for each mesh.

On a best-effort basis, maintains the look of the 3D model and its textures when new UVs are generated. If you choose to not enable this option, the current textures are not preserved.

Select the required size for the generated UV maps (pixels x pixels). You have the option choose 128, 256, 512, 1024, 2048, or 4096.

Keeps the texture pattern more intact, but can create more seams on the model surface.

Minimizes the number of seams that appear on the model. This can produce more stretching or pinching of the texture, depending on the model.

5. Click OK.
6. You can view the generated UVs under the Diffuse section in the Layers panel.

Target a texture type for painting

You can target eight different texture types for painting:

1. With your 3D model open, select 3D > Paint On Target Texture.
2. Choose the texture type that you want to paint.
   

Paint in the unlit mode

You can choose to paint your 3D objects in the unlit mode. This mode ignores any lighting in your scene and wraps raw texture data of the appropriate type around your 3D objects. Painting in the unlit mode lets you paint without shading and with greater color accuracy.

Follow these steps:

1. In the 3D panel, select Scene.
2. In the Properties panel, select Surface.
3. Select Unlit Texture from the Style pop-up menu.

Reveal surfaces to paint on

For more complex models with interior or hidden areas, you can hide sections of the model for easier access to surfaces you want to paint. For example, to apply paint to the dashboard of a car model, you can temporarily cut away the roof or windshield, then zoom inside the car to get an unobstructed view.

Set the paint falloff angle

When painting on a model, the paint falloff angle controls how much paint is applied to a surface as it curves away from the forward-facing view. The falloff angle is calculated based on a “normal”, or straight line projecting out from the part of the model surface that faces you. For example, in a spherical model such as a soccer ball, the falloff angle to the exact center of the ball as it faces you is 0 degrees. As the surface of the ball curves away, the falloff angle increases, up to 90 degrees at the edges of the ball.

Identify paintable areas

It may not be clear just from looking at a 3D model whether you can successfully paint on certain areas. Because the model view may not provide a 1 to 1 correspondence with the 2D texture itself, applying paint directly to the model is different from directly painting on a 2D texture map. What appears to be a small brush on the model may in fact be much larger in relation to the texture, depending on the resolution of the texture, or how close you are to the model when applying paint.

Good paintable areas are areas where you can apply paint or other adjustments to the model surface with the most consistent and predictable effect. In other areas, paint may be undersampled or oversampled due to your angle or distance from the model surface.