🟢Learn how to work with ID maps in Substance Painter, Maya, and ZBrush to assign different materials to 3D models.
🟢Explore techniques like subsurface scattering and opacity for realistic material effects.
- Workflow
For today's class, we’ll be looking at how to make ID Maps inside Autodesk Maya and ZBrush.
The first software we will be using is Autodesk Maya.
Place the backpack inside the project and make a duplicate of it.
This is going to be important for making the ID Maps.
Hide the original while working on the copy.
Select a couple of parts and assign them a new Lambert material and change the color.
Do this for every part of the backpack.
After you are done un-hide the original backpack and have both of them visible in the viewport.
Change the Workspace to Rendering and click on the Lighting/Shading menu.
From there select the Transfer Maps option.
A new window will open up with a lot of options.
The Target Mesh is where the original non-colored mesh should go while the Source Mesh is the place for the colored copy.
In Target Meshes, select the original mesh without the colors and click on the Add Selected button.
In Source Meshes, select the colored copy, and click on Add Selected and Defuse button.
Click on the folder icon in the Defuse color map and pick a location on your computer where you want the ID Map to be exported.
Once you choose a spot select a JPEG as the File Format and click on the Bake and Close button.
Your ID Map should be exported to the selected spot on your computer.
Zbrush Method
Now we’ll see what the process looks like in Zbrush.
Import the same backpack in the workspace and merge the backpack and rename it.
Turn on the Line Fill by using the Shift + F keyboard shortcut so we can see the polygroups.
Just like inside Autodesk Maya, we’re going to add the same polygroup to a couple of parts.
Since everything is merged we’ll select the parts we want to group up by selecting them with the polygroup selection method.
Hold down Ctrl + Shift and click on one of the buttons, it will only isolate that one but by still holding down Ctrl + Shift and dragging on the side it will bring back the rest of the backpack with only the isolated button now hidden.
Still holding down Ctrl + Shift, click on the rest of the buttons and other objects you want to add to their own shared polygroup.
After you’ve selected everything, Ctrl + Shift and drag on the side to reveal all the hidden parts.
From here just click Ctrl + W to give them a different playgroup and Ctrl + Shift and click on the side to reveal the rest of the backpack.
Repeat this process for all the parts you want to share a polygroup.
After we’ve grouped up everything go to the Polypain options on the side and click the Polypaint From Polygroups.
Now the polygroups will look more vibrant and saturated.
Add more divisions to the backpack so that we can use it as a high poly for the bake inside of Substance Painter.
Substance Painter
Inside Substance Painter, we’ll import the Low Poly and bake the high poly from ZBrush onto it.
Before we click on bake we need to go inside the ID Maps options and switch the Color Source from Material to Vrtex Color.
After we bake it we can see that there is an ID texture map in our Texture Set Settings.
To add the ID Maps from Autodesk Maya inside of the project you just need to drag and drop it into the scene, change it to a texture type Import to your current session then press Import.
Since we already have ID Maps from our high poly from ZBrush we don’t need to do this.
To see what is the use of ID Maps we’re going to make a fill layer with a red color and add a Mask With Color Selection.
We’ll have some interesting options in our project now that will let us color pick a color from the ID Map and it will only fill out the parts affected by that color.
Subsurface Scattering
Subsurface scattering creates a soft, glowing effect and makes the material look more realistic.
This is a natural phenomenon that happens when light passes through certain materials like skin or wax.
We can create this effect inside Substance Painter.
We’ll sue this orc model for this example.
Since it’s a high poly we can bake it with itself to get all the necessary maps.
On the skin shader, we’ll add a fill layer and choose a light skin pink color.
In the Display Settings, we’ll change the Environment Map to Studio 03.
In the same settings tick the Activate Subsurface Scattering.
Inside the Shader Settings make sure that the Subsurface Scattering Parameters are Enabled and the Scattering Type set to Red Shift + Rayleigh.
To add the Subsurface Scattering channel to our project, go into the Texture Set Settings click on the plus button on the Channels and select the Scattering.
On top of our skin layer make a new fill layer with only the scattering channel on and increase the intensity all the way to 1.
Add a black mask to the scattering layer and by using a normal brush start drawing out where the scattering will be on the character.
These parts are the tip of the nose, in-between the fingers, on the tip of the ears, etc.
For now, we’ll just add it to the ears.
To see how much of the scattering we are adding we can change the View from Material to Mask.
After we are done switch to the Material View and click on the render option to see how the scattering will look rendered.
Opacity
To activate the opacity we first need to go inside the Shader Settings and select the pbr metal rough with alpha blending.
Now inside our Texture Set Settings when we click on the plus in the Channels we can add the Opacity channel.
Go to the shader where the mouth stitches are and make a new fill layer with any color, in this case, it is blue.
On top of the blue layer make a new fill layer with just the opacity channel on and decrease the value to make the mesh see-through.
Exporting Opacity Texture Map
Click on File and Export Textures, from the Export Textures window go to the Output Templates.
From here copy the Unreal Engine 4 (Packed) and work on that copy.
In this copy in Output Maps click on the Create Gray.
Inside the Input Maps column find the Opacity and drag and drop it inside the gray square.
It will ask you what kind of channel you want it to be, select the Gray Channel and not the A Channel.
Now when you export the texture make sure you have the Output Template set to the Copy we made of an already existing one.
Then just export your textures.