GRAFFITI

About this project.

This project started off with that I wanted to learn about render targets since I knew nothing about them and I wanted to combine the uses of materials, blueprints, Niagara and UI while making something video game related.

What it is.

What this project shows is a train simply animated in BP. Then there is a color wheel UI that sets the color to a parameter that are used by the brush BP, spray can and particle material. The color selection is done by holding alt + LMB and the gray scale slider controls the value of the color. The size of the brush is controlled with the scroll wheel.

The 3D assets are gathered from FAB & sound effects are from free sound.

I went with creating a plane as my mesh for the render target since using the trains UV would cause obvious seams when I painted on the render target.

Overview of the main blueprint that draws onto the render targets.

Problems I had.

The main BP draws onto 2 render targets. One that gets the color and one that gets the alpha. This is because the node I wanted to use to create different shapes for the brush does not input color values so I worked around this by making 2 different draw nodes, one for each render target. One that writes to the alpha in the brush material and one that writes with a polygon on the color material.

Since the polygon brush creates ugly hard lines when already drawing over areas where the alpha is 1. I added a HLSL script that blurs the lines to better match with the alpha brush.

Alpha brush material. This is where the alpha gets its shape and noise.

Before I start up a painting session I make sure to clear the render targets to get a clear canvas.

Shader for the color picker UI.

If I had more time.

What I would like to delve deeper into would be more patterns for the spray brush, change flow depending on distance, add paint drip if you spray too long in the same spot and find another way of drawing the color to the render target. I would also like to see if I could spray directly on the train so I could get the shape and normals from the train.