Materials Study – Crystals/Gemstones – Strawberry Quartz

As I mentioned on my Patreon, as part of my materials studies in Substance Designer and Blender, I really want to work on crystals and gemstones. I’ve been collecting quite a few reference images on this Pinterest board over the last few months, and have decided that the first one I’m going after is the strawberry quartz.

I have a few ideas for how to best do this. I’m initially working in Substance3D to create the surface material, but I’m also planning to use a volumetric shader combined with the surface shader in Blender to create an effect that looks more like the quartz. Those red veins are not just on the surface!

So, for my first iterations of both surface materials and volumetric shaders, I have the following first six WIP attempts:

#1 was just the first run at the surface shader. It’s a little too busy, and both the quartz and the veins are running a little too much toward pink.

#2 added a multidirectional blur to calm down the veining a bit.

#3 added the roughness and metallic channels to the texture and drove the veins more toward red.

#4 was a touchup to all of the channels, but the UVs on the model were also not right on two sides (visible on the left side in the image). It also added the initial volumetric pass inside the crystal.

#5 minor touchups.

#6 fixed UVs, fixed up some coloring and the density of the volumetric pass.

So, during these steps, widescale changes were made in Substance to the material textures themselves. In Blender, after getting Cycles setup the way I wanted, I made some minor detail changes to both the volumetric and surface shaders. There’s still a lot of work to be done, but not bad for a little bit of time in the morning.

FWIW, the blue cube in the background of the renders is there simply to verify the level of transparency. I’ll probably change the setup some so that there’s a white/50%/black background with some frosted lighting coming in from underneath and slightly to the front. The surface itself looks pretty decent, though I’m sure there will be some fine-tuning. The major changes I think still need to be made are in the volumetric shader aspect.

Making Materials and Models! Mmmmmmmm (M)Normal Maps?

Not being an artist can seem like one of the most daunting parts of going it alone (or mostly alone) as an indie dev.  I’m a fair photographer, but that’s as far as my artistic capabilities have previously taken me.  Most of my stick figures look, well… disfigured, and things like straight lines are as simple for me as writing in Martian.  But I’ve been really working to increase my skill set here, and be able to create things in Labyrintheer that actually LOOK pretty decent.

In light of that, I started by picking up some great models from InfinityPBR.  Andrew, the awesome dude behind iPBR (as I reference it for myself) includes some great PBR materials as SBSAR files (and recently SBS files) that really helped me delve into how materials work and what was meant by all of the components: normal, roughness, metallic, height (or specular and glossiness depending on your preferred workflow); metallic/roughness versus specular/glossiness; and a bit about what all of those components can do.

But this wasn’t enough customization for me.  As I’ve mentioned before I started using Archimatix to design some architectural models (which is still something I’m getting a handle on, simply due to the sheer variability of AX and its nodes).  As I worked through some (very simple) wall models and such, I realized that I also wanted more control over the materials themselves.  iPBR offers an INCREDIBLE amount of customization, but I’m just a pain in my own arse that way.  So the next step was…  Substance Designer.

For those new to the art game, Substance Designer is an amazing software package that lets you node-author your own materials and export SBSAR files that can be used to procedurally create materials in Unity (and I believe Unreal Engine).

The beauty of the node-driven design is that, while artist-type folk seem to settle into it easily enough, we logic-driven code monkey types can also create some really stunning work since everything can be reduced to parameters and inputs and outputs.  But before you can do any of this, you need to grasp some of the basics.  I’m not high-speed enough yet to really offer a tutorial, but I can share the wealth of tutorial love that I’ve been using.  So, let’s start with normal maps.

Normal Maps

I ran across this tutorial literally this morning, which is what brought me to create this post and share this info.  More blog post, less actual tutorial, the information about normal maps here is presented concisely, tersely, and with excellent clarity.  Even someone who has never heard of a material in game parlance before can probably understand what’s being explained.

The gist of normal maps is to provide interaction between the materials and light in your scenes.  This is not the same as metallic/roughness aspects, but more to “pretend” that there’s dirt, smudges, small deformities or other similar features on your object.  When making a material, you often preview it on a perfectly flat surface.  But you still want to see the details – details that offer a 3D appearance on a completely flat 2D plane.  This is where normal maps come in.

Let’s look at the image below, for instance:

Demon Head Emboss - Coin Face
Demon Head Emboss – Coin Face

This is meant to be the head of a coin I’m working on as sort of a self-tutorial.  The eye can easily see this as an embossed image, but due to the normal map, moving the light around changes how and where shadows happen.  Here the light is off to the left, so left of the “ridges” (it’s still just a flat plane) looks brighter, and right of them produces shadows.  If I were to move the light source to the other side, the opposite would be true.  This is how normal maps help reinforce the 3D appearance of an object that doesn’t have detailed modeling done.  This is a HUGE benefit to game performance – it’s much easier to draw a coin that is perfectly flat on both sides, and apply this material to make it appear 3D than it is to produce a 3D model with this level of detail.  Easier both in actual creation of the object as well as on your GPU for rendering it.

This video shows the coin in Unity.  The scuffs and scratches are both part of the base color of the item, but the deeper scratches are also mostly in the normal map, and allow light to fall into them or be occluded from them based on the light angle.  Note that in the above video, the edge of the coin are NOT flat, those are actually angled on the model itself.  That would not be a great use of attempting to use normal maps to provide a 3D effect (at least not in any way I would be able to do it).

That’s what I have for normal maps, for now.  But I plan to continue this as a growing series of posts on PBR materials to help demystify them for those of us new to this whole thing.