3D Games production self directed: Understanding decals and vertex painting (Week 3)

For this week's self directed, I wanted to focus in on techniques used to break up textures and surfaces, analysing vertex painting and decals.

Vertex painting:

Vertex painting is a method where you can have multiple textures and make gradients between the two in order to add surface variation, this can be used on tiling textures with variation, such as, cracks, moss, darker or lighter tones etc.

This example from Overwatch's Malevento shows 2 clear distinct textures, they are both rounded brick/cobblestone arch pathways, but one of them contains plain brick with slight base colour variation, whereas the other one has moss loaded bricks.

These would have been created the same way, using the plain brick as a base, then just adding extra base colour variation on top and putting gradients between the 2 textures in the form of vertex painting.

A clearer example of texture variation

This next example is from the map Esperanca. There has been distinct texture variation put on to this single building, as this map has many saturated/bright buildings as a focal point of the map design/flow.

I have colour coded and highlighted the areas which I believe have varying textures, either vertex painted or used as decals.

One downside of having vertex painting like this is the amount of vertices you would need on any given plane. To paint in precise detail like this would require a lot of accuracy. Given the distinct variation between the textures here means there are probably a lot of vertices involved.

Similar example from the same map on a different building.

A very crudely designed vertex paint in photoshop, texture samples taken from Temple of Anubis consisting of Brick and Plaster, combined together to demonstrate what vertex painting is.

Another example of brick and sand vertex painted on Temple of Anubis.

Vertex painted sand and brick

A very minor example of where tiling textures have been used but have a noticeable line up error. (Nothing to do with vertex painting but just a point of interest to highlight.)

Decals:

In this example for Malevento, I believe this part of the paving is a decal.

I say this because the texture around it seems to tile seamlessly underneath the decal. The decal was made with PBR, like the other textures, however this would have been exported as an alpha for a decal in engine.

Malevento paving

This next example on Kings Row is a more obvious example for use of decals.

With decals, you have a lot more control over how they are created, in Photoshop you can use various brushes to erase edges and create the decal how you like and import it as an alpha to engine.

The poster on the left is a key example of a ripped poster, they could have erased around in photoshop to create that distinct effect.

Furthermore, the graffiti is a good example of the same technique being used but in the case of hand written messaging - giving you a lot more control over your textures.

Kings row decal examples

Here is another example from Blizzard world, where leaf alphas have been used as decals on the ground in order to break up the surface.

However, this one doesn't make much sense as where I took this picture, there are no trees around.

But the picture after, on the formerly mentioned map, with confetti on the floor makes more sense as the balloons above could potentially contain confetti in a real life scenario.

Blizzard world leaf decals

Blizzard world confetti

Example of hard surface decal usage. This could be applied to real life objects too, such as the logo of companies or insignias on planes, boats, tanks, etc instead of having to paint it onto the texture.