Quite a lot of progress has been made since the last update on creature progression so be prepared for a long post xD
After building and skinning the muscle rig it was time for the fun stuff. (more sculpting and texturing) Initially I had a few different ways I could go about doing this. I know I wanted to go further in the sculpted detail but with little time left I didn’t want to painstakingly sculpt in everything from scratch. Instead I looked once more to Javier Blanco’s pipeline and decided to take his approach. Which was building a sculpt driven by displacement maps stitched together in mari. For this option I needed displacement textures of various animal skin/scale textures, and lots of them. So I had taken my lecturer Steve’s advice and used CrazyBump to turn my texture library into useable displacements.
Once I had projected on my displacement textures where I wanted that detail on my creature, I then exported all the maps. From here I applied the maps as displacements in zbrush. Bam, instantly I had something I could work with, it was no where near perfect but it gave me a base on which I could build on.Â
From here I spent a day polishing the sculpt, I could have spent a lot more time detailing but I really had to move on to the texturing.
I gathered some references of the colours and patterns I wanted for this creature, such as these below-
From here I went back to Mari, this was the first time I had used Mari to texture, so I didn’t really know what to expect. I watched a tutorial to help me set up my scene and then had various tutes playing in the background while I worked away.
These were some of the ones I found useful-
http://www.digitaltutors.com/tutorial/1481-Combining-Painted-and-Image-Based-Textures-in-MARI
http://www.digitaltutors.com/tutorial/1603-Essential-Strategies-for-Hand-Painting-Textures-in-MARI
http://www.digitaltutors.com/tutorial/633-Combining-Painted-and-Image-Based-Textures-in-MARI
Firstly I painted a base texture, which consisted of various greens. One of the features I loved about Mari was the ability to drive masks made from channels. I used the maps that I had exported from zbrush (normal and displacement) to drive these masks. The control that you have on a channel mask is also amazing, you can play around with the curves and intensity to see in real time (if you haven’t baked your paint in) and see exactly how that affects the texture you’ve just painted/projected on. Mari also has the ability to calculate the AO of the model by the click of a button. You can then use this calculated AO as it’s own mask as well, with all the control of it as well. There were also many other procedural mask types that I played around with such as noise to get some variation in the pattern, colour that I was painting.
I used this techniques to hand paint most of my model, I also used a mixture of textures in places that I wanted to project certain details, such as the eyes, and also the bony areas of his body which I then tidied up by painting over. There are also some nice warping tools that you can use to really put the projected texture in places that you want it. For example I used this particular texture for his bony plates on arms and legs, but of course it wasn’t going to match up exactly however using the spline warper tools I could bend it and pull it to the shape I needed before baking it in.
One more thing that I used quite a lot throughout the process were the layer adjustments and adjustment stacks. For instance, I added a multiply adjustment to a layer which I would then drive by a mask from my displacement map or AO to get some nice dirt or darker colour in the crevices. I used this on the claws and spikes and then painted on the mask in places I wanted more dirt (like under the claws or where they meet the skin). I also ended up with the reddish colour on his bony head and back crest by accident, I was playing around seeing what an overlay of texture would look like with different blend modes like screen/lighten/colourburn etc. However when I hit contrast it made the places where I overlayed the texture and earthy reddy colour with tinges of purple in some areas. I really liked the look this achieved and the best thing about it was that it was completely unplanned.
After I had finished the diffuse texture, I also painted some other maps, like specular, gloss, reflection and emissive. While watching this tutorial, he mentions that we can fake subsurface scattering with an emissive map, I hadn’t thought of using emissive maps this way before and was interested to see the results it would yield. So I painted with a pinkish colour on a very low opacity in places where I wanted this, like on the cheeks, belly, fins, palms and mouth area. Once I had made all my maps I exported them out so I could compile it all in max.
My material setup was pretty complex as I had made the decision to use multiple texture tiles. I used composite maps to link up all my uv tiles and adjusted the U and V values on the bitmap parameters for each layer of the composite map.
 I did however encounter an issue with my displacement maps, when I exported them out from zbrush it exported all my subtools as different exr files and wouldn’t let me merge them in zbrush. So I had to use nuke to combine those that were sharing the same uv tile. I used merge nodes and then re-exported them out.
Once this was done, I went back into max and continued to setup my shader. Once this was done, it was time to play around with the displacement parameters. I wasn’t sure how to set this all up but I found this useful tutorial on that. It seemed like a really weird way of setting up the materials but hey, it worked so I’m not complaining xD
After doing some test renders I came to realised that my shader didn’t really seem to be doing anything, I even cranked up the specular and it made no difference. Then it occurred to me that because I was using vray to render, I also needed a vray material not a standard one. *facepalm* So I quickly changed that and reconnected all my maps. However now I realised I faced another issue. The vray material uses different parameters and instead of specular I needed a roughness map, along with two different types of gloss and reflectivity. At this point I went back into mari to paint some more maps.
 I made a roughness map, and also adjusted my reflection map to suit vray, at this point, I decided to also make a bump map (using procedurals and painting) just to bring out those little details and make my reflective and gloss maps really catch that. I wasn’t quite sure how to setup the vray shader to get the wet glossy look I wanted for the skin of my creature, as there were multiple different slots for reflection and gloss. I did some googling and found this setup that they made to make a wet road. So I plugged in my maps according to what they had done and it worked!
I did some test renders and continued to make small adjustments to my maps in mari until I was happy with the results.
If you stayed around to actually read all that then gold star for you ;p I’ll post an animation and breakdown sometime in the future too so keep your eyes peeled!