Published: 1st August 2018
My project at Lightmap this month was to create dirt and dust materials to be applied to a variety of wooden, metal and painted objects. The development of materials is a very challenging subject and by carrying out this project I was able to enhance my material skills further in order to produce the most realistic renders.
To create my dust and dirt material, I decided to use Cinema 4D alongside V-Ray and Octane. I chose this set up because I felt the most confident working with Cinema 4D, and saw this project as an opportunity to solely focus on the materials rather than experimenting with other software I was less confident with.
My first challenge was to apply dust and dirt to a wooden texture and after looking through a number of different references, I came across this really cute, characterful wooden mouse which I decided to use as my reference material.
Now that I had my wooden reference, I started by experimenting with Octane as this renderer had a number of useful material tutorials, which I have included below.
By following the tutorials, I was able to replicate the materials by gradually repeating the texturing creation process until I no longer needed guidance. The ‘screen captures’ below (using free models) demonstrate what I was able to create by replicating, adjusting and implementing the skills shown in the mentioned tutorial. I felt pretty happy using these techniques so I set out to develop the textures for the toy mouse scene, and my ‘render result’ can be seen below:
My next step was to recreate the results of my Octane render within V-ray by using similar methods found in the two tutorials below. I used my knowledge of Octane and adapted this to V-Ray as the process is technically similar, but the methods slightly differ. For example, many of the inputs and nodes share similar names and reactions, meaning I was able to save time by using the same settings and inputs in my materials as I did in Octane. I’ve included ‘screen captures’ of this process in V-Ray (using free models), and then re-created the materials for my scene using V-Ray. The final result is shown below.
I used HDR Light Studio to add lights to reflect off all the surfaces/materials in my scene. By using HDR Light Studio, I was able to maintain the consistency of lighting in both Octane and V-Ray as the software is portable and provides the same lighting set-up (HDRI map) for multiple render engines with precise results. Below is the exported HDRI from HDR Light Studio:
As a direct comparison, my Octane and V-Ray renders are side-by-side below to highlight the differences between both render engines. Each image includes dirt and dust shaders found in both packages, but a noticeable variation can be found on the ears which appear a lot darker in the V-ray render compared to Octane. The Octane render appears more subtle and draws the white scratches to the surface more than the black dirt marks.
Dust and Dirt Applied to a Painted Metal
After completing the wooden effect on the toy mouse, I set myself the challenge of applying the skills learnt previously to create dust and dirt on painted metal followed by an extra challenge of dust and dirt on a clean object. I felt a retro style radio would provide a really interesting shape and range of materials and came across these images as a reference to guide my model, texture and lighting workflow.
Octane – Clean Render
To create the glossy and metal surface material on my vintage radio I started with Octane, a render engine I have used on a number of past projects. My prior experience with Octane meant I able to develop these materials without the need for tutorials.
Octane – Dirt Material
Before I created the dirt materials on the radio, I developed a few different versions on a separate model, similar to the process I did with the wooden toy. The texture that worked the best for the radio was the one shown below titled ‘Screen Capture.’ I applied the dirt, dust and rust to the radio, and my render is shown below titled ‘Dirt Render.’
V-Ray – Clean
I then replicated the material process used in Octane but applied it to V-Ray’s material system. The material process for the clean radio I found to be just as straightforward as I have frequently used V-Ray in my previous projects and feel confident using it.
V-Ray – Dirt Material
I decided to experiment with my test scene before applying the dust and dirt to the model, which included testing lots of materials in V-Ray in order to fully understand the process. The ‘Screen Captures’ below highlight this experimentation. Once I had tested the materials, I applied them to the radio which is shown below in the ‘Dirt Render.’
The final four images below capture the results of both my Octane and V-Ray render. Each image features similar dirt, dust and rust shader, but in V-Ray, there is noticeably different colouring. The radio is much brighter and saturated, appearing much softer, whereas Octane has a darker, rustic tone
The dust and dirt material development project allowed me to explore V-Ray and Octane in more depth with the aim of improving my textures and material knowledge. I really enjoyed experimenting with textures and bringing the models to life with materials and lights.
The biggest challenges I came across mainly involved creating realistic dust and dirt in two separate render engines, followed by learning the advanced materials in V-Ray Material. The materials were particularly difficult because V-Ray is still fairly new to me and there were fewer tutorials available to aid my learning.
The two main learning points I will take from this project are the creation of dust, dirt and rust shaders using V-Ray and Octane, followed by enhancing my knowledge and confidence in shader development.