Texture Masking

Create Look by Masking with a Texture Atlas

01. Overview

Realistic, accurate paint wear can be challenging to capture. In this tutorial, we will be showing you a technique for simulating this kind of paint wear using a texture mask. Observe the material differences between the glossy paint and the worn wood beneath. A texture mask allows for an accurate recreation of the wear patterns present in this reference. Note that this is a texture atlas for use as a mask only. This technique is not for creating a texture atlas for any material channels.

03. Consistent UV Scale

For best results, make sure that your UV scale is consistent across your model. This is easy to check in the Edit UVWs window by selecting “CheckerPattern”. Your model’s checkboards should be of a similar size.

04. Consistent UV Scale

To use a texture atlas mask, we’ll need one UV channel laid out in 0 – 1 space (by default, the checkerboard area in Unwrap UVW). This is important because the mask texture will NOT be a repeating texture.

For this tutorial, we’ll only be using one UV channel, but be aware that you could use multiple UV channels if you wish, as long as the texture mask uses the 0 – 1 UV channel.

05. Construct Materials for the Metal Materials

Set up the material for the metal hinges and handles. To get more information about setting up materials, please refer to our Making Everyday Materials tutorial.

06. Construct Materials for the Base Wood Surface

Set up a material for the base wood surface lying beneath the paint. Don’t get hung up on the specific details. There will be an opportunity to adjust the material when the wood and paint materials are composited together.

07. Construct Materials for the Base Paint Surface

Now, set up a material for the pale painted surface as a separate material. Later we will layer these materials on top of each other using a V-Ray Blend Material, and use a mask to hide some of the paint to show the wood from the previous step.

08. Curvature Material Setup

The worn parts of the paint are mostly along the edges and corners of the cabinet. Painting the worn paint details will be easier if we render out a curvature texture to remind us where the edges are while we’re painting the mask in photoshop.

A curvature map is a texture that stores the concavity and convexity of model. Adjust the VRayCurvature sample spread and scale settings to keep the lines thin and local to the mesh’s edges.

09. Render the Curvature to Texture

From the Render Elements menu, select Render to Texture (hotkey “0”). Select all elements of the object (in this case, the drawer). You should see them in the “Object and Output Settings” list.

Under “Mapping Coordinates” select “Use Existing Channel” and select the UV channel of the unwrap you created. Finally, under “Output” click “Add” and select the VRayDiffuseFilterMap. Set the texture map size to at least 1024 x 1024. Set your Target Map Slot to “Diffuse map”.

Note that this will actually start a render, so it might take a few minutes to complete, depending on the complexity of your SKU.

10. Render the UVs to texture

The UVs will also be a useful reference while painting our mask in photoshop. To render the UVs to a texture, open the UV Editor in an Unwrap UVW modifier. In the Edit UVWs window, select Tools and Render UVW Template… Make sure the aspect ratio is correct and the texture size is the same as the texture you just baked out. Then click the Render UV Template button. Save the UV layout locally.

11. Combine the Curvature and UVs

Open the curvature map in photoshop. Add the UV map to a layer above it. Set the new layer blend to Screen and lower the opacity to around 40%. Now, you’ll be well equipped to paint the mask edge wear.

12. Make a Working Mask Layer

In Photoshop, we’ll be painting a mask for use on the dresser. The mask will determine which part of the dresser surface is wood and which is paint. For our mask, black will be paint and white will be wood.

13. Choose an Appropriate Photoshop Brush

In Photoshop, we’ll be painting a mask for use on the dresser. The mask will determine which part of the dresser surface is wood and which is paint. For our mask, black will be paint and white will be wood.

In Photoshop CC 2018, I’d recommend the KYLE Bonus Chunky Charcoal brush with some modifications to its Scatter, Count, Count Jitter, Opacity, and Flow settings.

14. Paint Damage Along the Curvature Edges

In Photoshop, we’ll be painting a mask for use on the dresser. The mask will determine which part of the dresser surface is wood and which is paint. For our mask, black will be paint and white will be wood.

In Photoshop CC 2018, I’d recommend the KYLE Bonus Chunky Charcoal brush with some modifications to its Scatter, Count, Count Jitter, Opacity, and Flow settings.

15. Gradually Build Up Paint Damage

Using the curvature information as a guide, paint white in the spots where you expect the paint damage would be.

16. Find an Appropriate Wood Texture

The damage mask will transition between paint and wood material surfaces. However, the paint material itself needs to reflect some of the wood grain. Let’s combine the damage mask with a new mask we will make from a wood texture

17. Reduce Saturation of the Wood

As part of a mask, we don’t need the color information. Press Ctrl-U and reduce the Saturation value to 0.

18. Overlay the UV Information

Add a layer for your rendered UV map and add it on top of the texture. This should allow you to see where any wood adjustments will get applied.

19. Wood Texture Orientation

Duplicate the wood texture layer and place it under the UV map. Press Ctrl-A to select the whole layer, and Ctrl-T to rotate the layer 90 degrees. Then, using the UV Map as reference, erase the top layer so that the wood tooth direction matches the SKU’s. So for example if the bottom layer of the wood texture is vertical and the top layer is vertical, erase the top layer in areas where the UV mapping indicates the grain should be going horizontally. Now add these two layers to your final mask image, below the painted damage layer from earlier.

20. Posterize the Painted Damage

If you find the grey values in the mask are producing washed out materials, try using Image > Adjustments > Posterize to reduce the mask to two levels. Set the painted damage layer to blend mode “Screen” above the wood texture layer.

21. Paint Final Mask Adjustments

Make sure you’re monitoring your mask’s effect as you make changes. Save the mask texture often and review your changes in VRay. Adjust your mask texture with the techniques you’ve learned until you are satisfied with the final product.