UV, Materials & Texture Standards

3D Modeler and Core Fundamentals

01. Getting Started

This section contains some tips and general workflow practices that we request all our model suppliers to follow.

02. UV Maps

a. UV Seams
Box mapping creates bad seams – instead, you should use Unwrap UVW and proper UV unwrapping techniques to create better seams and smooth transitions. Place the UV seams on natural boundaries: sharp edges, cloth seams, etc. Note that you can use a box map on applicable objects – like a table, for instance. But curved surfaces will always suffer.

b. UV Mirroring
The models below show the unrealistic effect created by mirrored UVs. You can mirror the model – but mirroring the UVs will create butterfly patterns that look unnatural.

c. Texture Atlases
Repeating patterns should never use a texture atlas. Instead, use a tiled texture and overlap the UVs. Note that in the example below the UVs on the right are rotated to match the direction of the wood grain.

However, when a surface pattern is non-repetitive (like the numbers on a clock face), it is OK to use a non tiling texture. However, the wood behind the numbers in the example below should be a separate tiling texture.

03. Textures

a. Copyright
It is very important not to violate copyright when sourcing textures for your models. This means that you should not just use search Google for textures.

If you search with Google, you must use the “Usage Rights” option, found under “Tools”:
Setting this to “Labeled for reuse with modification” means that these images have been flagged by their creators that they are free to be modified.

Other sources for texture imagery include using the supplier imagery on the website or textures from Textures.com.

b. Cropping from References
If you have to crop the texture from the reference imagery, use the highest quality image onsite and warp the texture as necessary. Don’t grab textures from a lower resolution image if you have a higher resolution one available.

Additionally, is homogenous and somewhat repetitive (wood, metal, leather, most fabrics), then use a high-resolution tiled texture. Use our shared material library, or download from textures.com.

c. Creating Curtains
For items like curtains, using an image directly from a photo will result in significant pattern distortion:

So instead, try creating a tiled texture of the pattern and applying it that way. In this case, you would create several patterns and then use Material IDs to apply the patterns to the model, using a different Material ID for each area of pattern. For more information on building tiling textures, check out this video tutorial.

d. Tiling Textures
Textured image files should tile seamlessly. Do not increase a texture’s tiling amount in the image file. Set the tiling in 3DS Max’s Bitmap node in the material editor.

04. Materials

a. Unique Materials
Each type of surface should have its own unique material and, if applicable, its own texture files.

Multi-sub-object materials are OK as long as all materials have their own material nodes.

Do not use texture atlases and one material node to represent multiple materials.

b. Texture Direction
Instead of using multiple materials to change the direction of a texture, lay them out properly in the UV editor. Avoid multiple materials and textures for the same material – create as few materials as possible.

c. Reflect/Glossiness

i. If the Reflect texture has an alpha channel, “Affect channels” in the material properties window must be set to “Color only”. Otherwise the texture will cause the model to be transparent in areas.

This is also important for all materials in the “Coat” slot of a VRayBlendMtl material.

Below, you can see what happens when this effect is both correct and incorrect:

ii. For photorealism on reflective materials, use “scratch” and/or “dirt” textures in the RGlossiness slot.

Reflective surfaces that do not have a RGlossiness map are unrealistic because they are too perfect. The RGlossiness map makes reflections less uniform and more photo-realistic.

Reflective Glossiness (RGlossiness) controls where reflections are sharp or blurry. Brighter values are sharper, darker values are blurrier.

A mirror is mostly reflective but fingerprints and scratches make the reflection blurry.

d. Metals
Two common issues are seen in metal materials:

i. Colors should not be in the diffuse channel for metal materials. The diffuse should be set to black, and the color of the metal should be placed in the reflect channel.

ii. The IOR should be high for metals.

e. 2-Sided Materials
For lamp shades and curtains, use 1-sided geometry and VRay2SidedMtl to show translucency.

We add a light inside a lamp shade, or sun behind a curtain. Light and shadows show through the other side of the model.

This teapot has a VRay2SidedMt. The light inside creates a brighter area on the outside.