UV Mapping - Week 3

 UV Mapping

What are UVs?

• UVs are two-dimensional texture coordinates that reside with the vertex component information for polygonal and subdivision surface meshes.
• Uvs are the two-dimensional texture coordinate system, and they provide the connection between the surface mesh and how the image texture gets mapped onto the surface mesh.
• UV texture space uses the letters U and V to indicate the axes in 2D
• UV texture space facilitates the placement of image texture maps on a 3D surface.

Why the UVs?

• UVs are necessary as that they provide the connection between the surface mesh and how the image texture gets mapped onto the surface mesh.
• Textures applied to polygon or subdivision surfaces that do not possess UV texture coordinates will not render properly or will distorted.

What is UV Mapping?

•  UV mapping is a process whereby you create, edit, and otherwise arrange the UVs.
• The UV mapping process results in a correlation between the image and how it appears as a texture when mapped onto the three-dimensional surface mesh.

UV Editor:

Tools in the UV Editor to lay out and manipulate the 2D representation of UVs.

Practice 1:

Starting with a cube as maya doesn't change the UV's automatically if we stretch the polygons so the texture will be out of proportion, so we need to make new UVs (UV editor) to fix the issue.

To fix the texture, we opened the UV editor toolkit>Unfold along (U-axis), we can see during the process that some planes are large more than the space or not equally sized/proportional for that we need to go to transform>tools>Texel density and scale one object according to our wish and click Get button, select other object which we want to equally sized and click set to get the desired results. after that position each object in U1V1

As we can see the texture isn't seamless, rather than doing that manually by mix matching shapes, there's a better way to do it by selecting the edges of the shape and go to Cut and Sew>Stitch together, we can't stitch every edge but try to give the best shape for viewpoint and if we try textures they'll be seamless as well.

 

Practice 2:

In this practice we are working with UDIM, what are they and why they are important and a practice to show as an example.

What are UDIM?

UDIM stands for U-Dimension, represent coordinates of a texture, essentially giving you unique texture tiles.

Why UDIM is Important?

UDIM is a modification to the UV mapping workflow that ultimately makes things much more flexible.

Practice/Experiment: 

Opened the model by Francois Boquet, deleted the previous UV so we can make our own by scratch by using UDIM so we can maximize the resolution for our texture, starting by isolating the body of a character, then go to the UV>Planar Mapping(options) and reset the settings , click on the Z-axis and apply that.

Select the cut and sew tool and cut the parts of the body to present it in a 2D dimension mesh for UV, drag to cut and Ctrl+Drag to sew (don't forget to open the symmetry tool) to create the seams so we can unfold those shells into UDIMs, make sure to perform the mesh cleanup

start unfolding them by selecting them in UV editor and drag them to side while pinching the shapes of a character where needed specifically for the face.

Adjust the texel density, make sure it's same for all body to have a seamless effect

Let's include the eyes with the body, for other parts of the character we don't need to include UDIMs. For the eyes part, select the eye and go to UV>spherical, press 3D Cut and sew icon, right click, select edges and cut it in half and unfold it. Transfer attributes to the other eye the repeat the process.

Same procedure for 3D cut and sew, unfold goes with pants and applying the texel density.

As tis goes with tie, suspenders, shirt and eyebrows of the character of a character.

Self-Critique:

What I've Learnt and find challenging and What I can Change in future?

• The whole process was time taking and exhausting, I'll prefer to do this all work in one sitting as more time you give the more days it'll take.
• I was doing unfolding, Texel density one by one in the start, next time I'll try to see what happens if I do all at once
• The stitch together features saved me alot during the work
• More the practice, more it'll help to build muscle memory, so I'll practice the UV mapping in future as well