So first up we're going to talk about some texturing theory and define a few terms.
It's super important stuff, but can be hard to get your head around so we won't go too in-depth or anything
Mari channels are a container of layers or nodes usually resulting in a texture map that will help calculate something in our shader.
If we look at reference images we can start to dissect a few channels that we may need to recreate.
I think this picture is great to demonstrate what I mean because we have different sections of wet and dry.
If we were going to recreate this
we would need a base color to inform the hues and the values of the stones and this is often our first map.
After that would want to create a channel that calculates the amount the geometry would appear to raise or lower.
So we could achieve this with a bump, displacement, or normal map.
Another map we'd want to paint would be a map to calculate the reflection
that we are seeing only on one side, a
Specular roughness map would tell our shaders where we want the specular to be tighter and where we want it to be more matte.
If we quickly look at our shaded window in Mari,
you can see how changing a value such as the "specular roughness" changes the shaders response.
In Mari any channel
you make can be plugged into one of these slots giving you an idea of what kind of maps and channels you can make.
If we head over to the channel window we can start to discuss our next topic, color versus scalar data.
I think the Foundry's online documentation sums this up really well. Color data is what you see and scalar data is what is calculated.
Your base color channel will be seen at render time, the colors that you use in that channel will be the colors of the rendered
geometry. The view transform, a topic that will go into more later on will be enabled
So your linear textures will be viewed with a LUT, in this example sRGB.
Specular channels on the other hand,
such as speck roughness, displacement and masks - all just data channels from 0 to 1 that are used to calculate different things.
When you tell Mari a channel is scalar,
it will automatically turn the view transform to raw so you can see your values as pure data with no LUT.
Next up, image depth. You may have heard of 8-bit, 16-bit and 32-bit images.
All this means is the amount of data an image holds. 8-bit is 256 values per channel.
16-bit is
65535, and 32-bit is a whole lot more.
32 float point means we no longer store
colors as numbers like grey which is 128, 128, 128,  is now a decimal of 0.5.
The float means that the decimal point can move giving you the ability to have values of 10 and up.
Finally, let's briefly talk about two words you're going to hear a lot of in texturing, sRGB and linear color spaces.
Linear is a color space in which pixel values equate to light intensities. Light in the real world is linear
so there is a direct correlation between it and real-life.
Lighting and 3d packages are linear, so your textures need to be at render time as well.
sRGB, standard red green blue is the color space most online images are encoded with and how monitors and TV display images.
It has a gamma of roughly 2.2.
So that's quite a lot to wrap your head around
so we're going to leave this video here, but it's super important stuff to know and these terms are going to be terms that you're hearing every day when texturing. Thanks for watching
