UV Grid
Generates a labeled, seamlessly tiling color grid whose letters, numbers, and arrows show a model’s UV stretching, seams, and flipped islands.
Wire UV Grid into 3D Render’s Texture input and read the model:
- Stretching: cells that are not square.
- Seams: labels that jump from one cell to an unrelated one.
- Flipped or turned islands: arrows that do not point the same way as their neighbors.
3D Render UV Grid has no inputs and one Image output, and the output tiles seamlessly. Its partner UV Layout draws the same UVs flat. 3D Render’s Add UV Layout button builds both for the model it shows, with the grid wired onto the model and under the layout (see Add UV Layout).
The grid
Section titled “The grid”- Width and Height set the size (2048 by 2048 by default). The cells divide the image, so on a non-square texture each cell covers the same share of the 0 to 1 UV square rather than the same number of pixels across and down.
- Color Mode is RGBA or Grayscale. Grayscale is a single-channel image and always uses the Checker style.
- Columns and Rows run from 1 to 24 (8 by default). Rows are lettered A to X and columns numbered from 1.
- Subdivisions (1 to 16, 4 by default) splits each cell side into parts with thin dark lines inside the cell; 1 draws no lines. Line Width sets their width in pixels. No line is drawn on a cell’s edge, which keeps the grid seamless.
Colors
Section titled “Colors”Style is Colors, cells colored from a gradient, or Checker, two neutral grays alternating.
With Colors, Gradient is the same gradient editor and preset menu as Gradient Map, Spectral by default, and Color Layout decides how its colors fill the cells:
- Strided places the colors on diagonals with each cell several steps along the gradient from its neighbors, so no two neighbors look alike.
- Ordered uses the same diagonals with each cell the next color, which suits a gradient of hand-picked, unlike colors.
- Smooth (the default) runs the gradient across the columns with every other cell darker.
Steps (2 to 12, 8 by default) is how many colors Strided and Ordered take from the gradient. The count moves to the nearest one that divides both Columns and Rows, so the colors continue across the texture’s edges, and a status line says when it moved or when the grid’s sizes leave no seamless count. Add Grays adds a dark, a mid, and a light gray to those colors.
Smooth and the Checker style tile cleanly only with an even number of columns and rows.
Labels and arrows
Section titled “Labels and arrows”- Labels names each cell: Grid (row letter, then column number: A1), Coordinates (column and row from 0: 0,0), or None.
- Count Rows From decides which row is named A (or 0). Top (the default) matches ArcBrush’s own UV origin, glTF, and image pixels; Bottom matches apps and formats that count UVs from the bottom-left. Only the names move, never a pixel.
- Arrows under each label point at the image’s top, and with Up and Right also at its right. Up (the default) catches a top-to-bottom flip and any rotation; Up and Right also catches a left-to-right flip.
- Mark Size (0.1 to 0.5, 0.2 by default) is the label height as a share of the cell’s shorter side; the arrows follow.
Labels and arrows are black or white per cell, whichever reads better on its color. A Mark Size too large for the cells is reduced so every label fits, and marks too small to read are left out; a status line says which.
Parameters
Section titled “Parameters”Pins
Output
Output width in pixels. The cells divide the image, so on a non-square texture they are as wide as the 0 to 1 UV square shows them
Output height in pixels
Grid
Cells across. Smooth colors and the Checker style tile cleanly only with an even number of columns and rows
Cells down, lettered A to X
- Colors: cells colored from the gradient.
- Checker: two neutral grays alternating.
How the gradient's colors fill the cells.
- Strided: Steps colors on diagonals, each cell several steps along the gradient from its neighbors, so no two neighbors look alike.
- Ordered: the same diagonals, each cell the next color; suits a gradient of hand-ordered, unlike colors.
- Smooth: the gradient across the columns, every other cell darker. It jumps back to the gradient's start at the left and right edges, and tiles cleanly only with an even number of columns and rows.
How many colors are taken evenly from the gradient. The count moves to the nearest one that divides both Columns and Rows, so the colors continue across the texture's edges
Adds a dark, a mid and a light gray to the colors
Parts per cell side, split by thin dark lines inside each cell. 1 draws no lines
Width of the subdivision lines in pixels
Gradient
Number of stops; additional s2..sN are injected dynamically
Stop 0 normalized position
Stop 0
Stop 1 normalized position
Stop 1
Color space used to blend between gradient stops.
- RGB: blends the color values as stored.
- Linear sRGB: blends in linear light, with brighter midpoints.
- OKLab: even steps in perceived lightness.
- OKLCh: perceptual, around the hue wheel (Hue Path).
- HSV: around the hue wheel (Hue Path).
- Kubelka-Munk: mixes like paint pigments.
- Constant: no blend; each stop holds until the next.
Direction taken around the hue wheel between stops.
- Shorter: pick the shorter arc (default).
- Longer: pick the longer arc; useful for two-stop rainbows.
- Increasing: hue value monotonically increases.
- Decreasing: hue value monotonically decreases.
Marks
The name written in each cell.
- Grid: row letter then column number from 1 (A1).
- Coordinates: column,row from 0 (0,0).
- None: no names.
Which row is named A (or 0). Only the names move, never a pixel.
- Top: matches ArcBrush's UV origin, glTF, DirectX, image pixels and uvchecker.
- Bottom: matches Blender, Maya and OpenGL.
Arrows under each label pointing at the image's top (and right), so a flipped or turned island shows on the model.
- Up: catches a top-to-bottom flip and any rotation.
- Up and Right: also catches a left-to-right flip.
- None: no arrows.
Label height as a share of the cell's shorter side; the arrows follow. Reduced when a label would not fit its cell
Usage Tips
Section titled “Usage Tips”- Choose Up and Right arrows when a left-to-right flip matters, such as lettering or a logo on a mirrored part.
- Lower Columns and Rows on a small or low-detail model so the labels stay readable in the render.
- Keep Columns and Rows even and the grid repeats with no visible seam when 3D Render’s UV Tiling is above 1.
- Switch Style to Checker when the colored cells compete with a UV Layout’s fill and tints drawn over the grid.