Watercolour 3D Art

During a 30-day art challenge in September 2023, I began to play around with my style. I was particularly drawn to the idea of producing 3D art with a 2D aesthetic, and watercolors seemed like the perfect medium for this exploration.

To achieve this effect, I began by creating the texture for the world. I utilized a free paper texture image from https://pixabay.com/, which I then customized using a combination of a Hue/Saturation/Value node and an RGB Curves node.

Then I plugged this paper texture as the B color in a Mix RGB node, with the A color set to pure black. The factor for this mix was determined by the Camera Ray Light Path. Finally, I connected the output of the Mix RGB node to the background node with a strength of 1.

After establishing the world, I proceeded to set up the lighting. I positioned 4 light areas within my scene; 3 encircling the object and 1 positioned above it. All of these had a power of 8 W and a white color.

With the world and lighting in place, it was now time to focus on creating the watercolor material.

First of all was necessary to create a normal map with three layers of noise. Each was connected as a value A to Multiply node and all were multiplied by the value of 0,70. All outputs from Multiply nodes were combined with Combine XYZ node and by vector math Add node combined with a normal Geometry. 

From the Vector Math node, I divided the flow into two branches of nodes: one to define the illuminated parts of the object and another for the edges.
In the branch for illumination, the output of the Vector Math node was connected to the Normal socket of the Principled BSDF. Then, the Shader was converted to RGB. Subsequently, two Color Ramps were added: one to define watercolor effects and another for the actual colors.

The output from the vector math from the normal map was also plugged into the Layer Weight node with the blend value of 0,20. The Fresnel output was connected into two Color Ramps, which then were put together via Multiply node. The output of the Multiply node was then connected to another Color Ramp, which defined the color of the edges. 

The output of the last Color Ramp from the edges node branch was then plugged into an A value of Multiply RGB node. As a B value, the paper texture from the world material was used and the Factor was set to 1.
Then second Multiply RGB node was added and the result from the previous one was used as a B value. For an A value, the output from the last Color Ramp from the light node branch was used and the factor was again set to 1. The second Multiply RGB was connected to the Emission Shader with the strength of 1. 

All connected together should then look like this.