Game Ready Door Tutorial part 2 – Maya Quad Draw, UV mapping and Baking in Substance Painter

This is part 2 of my door tutorial trilogy, we will be using Quad Draw in Maya to create a game friendly model, UV mapping and baking in Substance Painter.

Baking a high detail model into a texture reduces performance impact when used in a game, animation or cg blockbuster. Using polygons, sometimes 10’s of millions of polygons like Zbrush or 3D scans would have a huge impact on performance. Quad draw is Mayas retopology tool that allows us create new polygons on the surface of a 3D model. The decimated model created at the end of tutorial part 1 can be used as a guide to trace out our new topology, we then make a UV map that will determine the shape of our texture. The last 10 minutes of the video is baking in Substance painter, and when we extract textures from our high poly door parts.

The video tutorial for part 2 can be watched here:

There will be another part to this tutorial in which we explore Substance Painter and making a PBR material, we will then export all to Unreal Engine so we can animate a character going through the door.

Go to this link for part 1: https://escapestudiosgamesart.com/2020/03/06/game-ready-door-tutorial-part-1-zbrush-hard-surface-modeling-and-photoshop/

In the last tutorial “Game Ready Door Tutorial part 1” we created 4 files Door_high, Door_Handle_high, Door_low, Door_Handle_high and Door_handle_low they can be downloaded from here: https://we.tl/t-JCfnwvtzz9

Below is the written instructions for this part of the tutorial,

A common problem with quad draw is creating endless loops that are difficult to edit or UV mapping. We can reduce the chance of this by starting a new loop of polygons around the handle, by connecting this with the quads already made will ensure that the loops only go around the handle once.

You have now completed the quad drawing stage. Go over your entire model and check that the new low poly matches the shape and position as the original high meshes.

UV Mapping

In Maya change the work space to UV editing, turn on the shaded view and enable the checkerboard function.

The image below can now be achieve with cut, stitch together and unfold. Mirror the handle when complete and duplicate the hinge and position over the second hinge.

Substance Painter

For this section I will just focus on the baking process in Substance painter, this is when we take the high poly meshes and create a material from them.

Go to file new, the document size is 2048 and type is unreal engine. The file to be selected is the door_low that we just exported.

Go to texture set settings > bake mesh maps

Output size can be set 2048 texture size (4096 if your computer can handle it)

High Definition Meshes should be door_high and Door_handle_high.

Set the Anti aliasing to 8 x 8.

turn on By Mesh Name under Match.

Then finally Turn off Thickness in the Mesh Maps list.This is only required for subsurface.

Now Press Bake, Wait…….. We now have all you Zbrush sculpt information printed onto the 6 textures. Check the Normal map for any errors, you may need to trouble shoot using the output log. If you have bake errors I make some suggestions in the video that might help.

The textures created are:

Normal: A tangent space normal map is an image that utilities the RGB channels to store a direction at each pixel.

World Space Normal: A normal map which contains normals coordinates relative to a fixed frame in the object space.

ID: Material ID maps are textures that contain colour information based upon the number of imported High Poly mesh parts, with each mesh being assigned a unique color. They are useful for texturing purposes; allowing selection masks based upon different materials on a mesh.

Curvature: a texture that stores the convexity/concavity of the mesh.

Ambient Occlusion: A map that creates soft shadowing, as if the model was lit without a direct light source.

Position: Gives you the vertical position on the mesh. You can use that to add damp at the bottom of an object.

The door model is now ready to texture in Substance Painter. Below is some renders of just the baked mesh and wire frame image.

I made a quick example of how a texture could be created, this will be developed further in the next video. It is quick and easy to make many variations from this one mesh. In the next tutorial we will do a full texture pass in Substance Painter, add animation and assemble the working door in Unreal Engine with animation.

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