Multi-Tile Displacement Workflows with Mari & Arnold | Endomychidae Beetle | Adam Spring | Official Website
Multi-Tile Displacement Workflows with Mari & Arnold | Endomychidae Beetle | Adam Spring | Official Website

The Endomychidae family are found worldwide, occurring in all major biogeographical regions; however, the group is predominantly tropical with highest diversity in the Neotropics, equatorial Africa and Southeast Asia. Also, this particular beetle mostly lives on eating mushrooms; hence it’s nick-name the ‘Handsome Fungus Beetle’.

It has been a few months since my last post on this Endomychidae beetle character. Apart from being caught up with other work, my slow progress has been due to some technical hurdles of which I will go into more detail later. The purpose of this project was to explore a new set of tools and software, however, this has undoubtedly made the project more challenging and a much longer process. All part of the fun… right?!

In the title of this post I mention a multi-tile displacement workflow between Mari and the Arnold render engine for Maya; however, this workflow requires you to use a number of other applications. Working between each of these application can be quite complicated, because typically they don’t all deal with your files in the same way; in fact the majority of the time they all work very differently from one another. It is for this reason that I have learned the importance of understanding the whole pipeline before starting out on a project. Obviously, this was something I had slightly overlooked and it turned out to be be one of the biggest, and most complicated learning curves I have experienced during my time working with characters in 3D. However, do not let me scare you from having a go, once you get your head around the software, everything starts to fall into place and the whole workflow begins to look very simple!

Below you can see how the beetle character has developed since my last blog post, and further down the page you can read a summery of my research into the multi-tile displacement workflow.

When it comes to multi-tile texturing, I have learned that one of the key time saving steps is to ensure that the left and right side of your character UV’s are symmetrical (image right). After doing this you can paint much more efficiently in Mari and copy / paste any base texture work across from one side of the character to the other.

Another time saving tip is to sculpt an array of displacement patches on a plane in ZBrush and then bake each of them out as a 2D transfer to use in Mari by simply projecting them onto the character model through the paint buffer. For the beetle I sculpted a selection of scars (see image left below). Once these scars were imported into the Mari paint buffer, I then scattered them across the character and layered them on top of the mid level displacement map. Each of these transfers can be used multiple times and modified using Mari’s grid warp tool to break up any repetition and help the transfers fit the form of the characters’ body.

Once the displacement map is looking finished inside Mari you might think that you are now ready to export to Maya and begin rendering… I tried this and the results were pretty shocking; it turns out that an extra stage of refinement is required using a basic comp set up in Nuke.

Firstly, you have to bake out each element as a separate layer from Mari i.e. scars, leather, dimples, etc..

The next step is to refine the displacement map in Nuke. You can set this up however you like, I used a simple left / right comp for each object (see above). It may take a few attempts to perfect this stage, jumping between Nuke and Maya, playing with the opacity of each layer and tweaking various different grade nodes.

Once you have got everything working correctly you should find that you get a remarkably accurate displacement on your model when rendering from Maya with Arnold – wohoo!

See Below my latest Endomychidae turntable:

There were a couple of great links I found that helped make this process easier; one of which was a post on CG Gallery –  http://www.cggallery.com/tutorials/displacement/. If you scroll to the bottom of the page you will find a really helpful ‘modeller to renderer’ settings/attributes guide.

(See bellow a screenshot of the guide I used for the beetle project).

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