ANI213 - Week 5

Substance - Blending Modes

Low dynamic range means values with 0.0 to 1.0. High dynamic range extends beyond those values.

Add & substract are the basic blend modes.

The order of images with Add doesn't matter, the values will be added and have the same result wither way - commutative. Areas with white already at 1.0 will not go higher and are clamped at 1.0 when using low dynamic range. Add is great for height maps.

Subtract does the opposite. It takes away values and makes the image darker. Unlike Add the order of layers does matter. Useful for removing detail. Black areas are not effected.

Height maps in Substance Painter use high dynamic range by default so clipping is not an issue.

Multiply is commutative. Order of layers does not matter. For low dynamic range images, multiply will only ever make results darker. If areas in the top and bottom layer are both white, then the result will remain white (1.0 x 1.0 = 1.0). Differing areas will darken based on their values (0.3 x 1.0 = 0.3). Multiply is great for masks. When using multiply for heightmaps, it acts by scaling the pixels down. Results are smoother than subtract.

Divide can quickly hit the value range limits. It is noncommutative so layer order does matter. It is not useful with height maps but sometimes masks. Some edge cases for divide is using it with similar looking noise maps.

Min (often called "Darken" in other software) takes the lowest value from either top or bottom and thus does not get affected by low dynamic range. Min is commutative and results look similar to multiply. It only affects the brighter areas but sometimes ignores a compenent if it is too bright. For heightmaps it works like a boolean intersection option. Good for clean clear transitions.

Max (often called "Lighten" in other software) takes the highest value from either top or bottom and is also not affected by low dynamic range. Also commutative. Gives a brighter result similar to Add. It can ignore a component if it is too dark. Works great for heightmaps, acting like a union boolean operation like merging objects together in 3D.

AddSub works based on the values of the top component (noncommutative). If the value is over 0.5 grey then the result is brighter, darker than 0.5 grey becomes darker. Exactly 0.5 remains the same. It is a combination of Add and Subtract. Great for masks where there are blurry transitions. Treat with care for heightmaps as it is doing two harsh operations at once.

Overlay works similar to AddSub but is a combination of Screen and Multiply. Order of components also matter (noncommutative). Not as harsh as AddSub so for adding variation in masks. May not work on areas too dark or too bright. Very subtle effect on transitions. The soft nature of Overlay is great for height maps.

Height maps in Substance Painter are set to Add by default.

UDIMs

When setting up a new project in UV TIle settings turn on "Use UV Tile workflow" and select "Preserve UV Tile layout per material and enable painting across tiles" to use UDIMS.

Individual tile resolutions can be changed in Substance so more detail can be added to parts of the model that need it.

UV tile masks allow for painting on specific tiles however the paint is still painted on all tiles, the UV mask is just for optimisation. To have brush strokes only affect the nonmasked tiles there is a button called "Paint strokes ignore masked UV Tiles."

When exporting UDIM textures "$udim" is used to add the tile number to the file name.

Baking Textures

Baked maps are utilised by map generators to add wear effects.

Dilation size in common properties affects the amount that the texture overlaps with UV borders (basically padding). Apply diffusion will bleed the texture all the way to the border.

Max Frontal Distance defines the origin point where rays are cast into the scene.

Relative to Bounding Box affects the Max Frontal Distance and makes it act like a percentage. If turned off then the MFD will be based on the size of the mesh itself.

Match effects neighbouring gemoetry.