Overview

Vertex coloring is an efficient technique to add color details to a model without using texture maps, which can save on memory and improve performance. In Sceneri, vertex colors are an excellent way to add variation, highlights, or detail to geometry. This article will walk you through painting vertex colors in Blender, exporting the geometry, and importing it into Sceneri.

Why Use Vertex Coloring?

Vertex coloring applies color information directly to each vertex of a 3D model. This approach offers several advantages:

• Low Memory Usage: Vertex colors don’t require additional texture maps, keeping memory usage low.
• Efficient for Color Variation: Ideal for adding color variation to models (like terrain or foliage) without adding texture files.
• Directly Editable in Blender: You can paint and adjust colors directly in Blender, giving you more control over the look of your models before import.

Follow these steps to add vertex colors to a model in Blender and prepare it for export to Sceneri.

Step by Step Guide

Set Up Your Model

1. Open Blender and Load Your Model:
   • Start by opening Blender and loading the model you want to color. You can import or create a model in Blender that you plan to bring into Sceneri.
2. Switch to Vertex Paint Mode:
   • Select the model in Object Mode.
   • From the mode dropdown menu (default is Object Mode), switch to Vertex Paint mode. This mode will allow you to apply colors directly to the vertices of the model.

Paint Vertex Colors

1. Choose a Brush and Color:
   • In Vertex Paint mode, look at the top tool panel or in the Tool Settings on the right. Select the Draw brush (it’s the default brush), and choose a color from the color picker.
   • Adjust the brush size, strength, and other settings as needed.
2. Start Painting:
   • Click and drag on the model to begin applying colors. The color will be applied to each vertex and will blend across the faces of the model based on vertex density.
   • If you need more precision, zoom in and adjust the brush size.
3. Add Color Variations:
   • To add variations, choose different colors and paint in areas where you want contrast, shading, or different hues. You can use Alt + LMB (left mouse button) to sample colors on the model if you want to maintain color harmony.
4. Use Masks or Selections for Detailed Painting (Optional):
   • For more control, you can switch to Edit Mode to select specific faces or vertices, then return to Vertex Paint mode. Painting will only affect the selected areas.

Preview and Finalize Vertex Colors

1. Preview with Shading:
   • In the top right corner of the 3D Viewport, switch to Material Preview or Rendered view mode to see how the vertex colors look with the lighting setup.
   • Tweak colors as needed to get the look you want.
2. Set Vertex Colors as the Active Color Layer:
   • In Object Data Properties (the green triangle icon), locate the Vertex Colors section to ensure your vertex color layer is active.
   • Rename the vertex color layer if needed, so it’s easy to identify during export.

Exporting the Model with Vertex Colors

1. Prepare for Export:
   • Switch back to Object Mode and select the model.
   • Go to File > Export and choose FBX or GLTF. Both formats support vertex colors and are commonly used for importing assets into Sceneri.
2. Export Settings:
   • For FBX:
     • In the Export FBX panel, ensure Mesh is selected under Limit to.
     • Make sure Apply Modifiers is checked if you’ve used any modifiers.
     • Confirm that Vertex Colors is enabled in the Geometry tab.

Conclusion

Vertex coloring is an efficient way to add visual detail without the need for textures, making it ideal for game engines like Sceneri. By following this workflow in Blender, you can create and export geometry with rich color information that will import seamlessly into Sceneri. This method not only optimizes memory use but also provides creative control over the appearance of your models in-game.