Chapter 3 · Modifier Reference

3.11Tnpix Preserve

The Tnpix Preserve modifier makes a painted region follow the animation of the mesh below the Tnpix Solver — a Skin, a Skin Wrap, a Tnpix Wrap, a Morpher, a Point Cache, anything that moves the mesh — instead of being simulated. A collar, a cuff, the top of a sleeve or a waistband rides the character exactly, and a soft edge blends it into the simulated cloth.

Location: Modify panel ▸ Modifier List ▸ Tnpix Preserve

To make a region follow the character's animation:

Make sure the animation reaches the cloth below the Tnpix Solver: the cloth is skinned, wrapped or otherwise deformed by modifiers under the Solver.
Paint the region in a Tnpix Channel, for example a channel named cuffs: 1 where the cloth must sit on the animation, falling to 0 over a few rows where it should blend into the simulated cloth.
Add Tnpix Preserve and choose cuffs in Channel.
Play from the first frame. The points painted 1 sit on the animation, the soft edge follows it part of the way, and the rest of the cloth is simulated.

What the paint means

Painted	The point
1	Sits on the animation exactly, on every frame, the first frame included. Nothing moves it: it is ignored by every collision — the colliders, the ground, self collision and the other garments — and it pushes nothing.
Between 0 and 1	Is pulled toward the animation by the Pin's Weight rule: 0.5 follows half of it, 0.75 three quarters. It is still simulated, so it still collides.
0	Is simulated, as without a Preserve.

Painted

The point

Sits on the animation exactly, on every frame, the first frame included. Nothing moves it: it is ignored by every collision — the colliders, the ground, self collision and the other garments — and it pushes nothing.

Between 0 and 1

Is pulled toward the animation by the Pin's Weight rule: 0.5 follows half of it, 0.75 three quarters. It is still simulated, so it still collides.

Is simulated, as without a Preserve.

Its place in the stack does not change what it follows: the mesh as it arrives at the Tnpix Solver, so every deformer below the Solver counts. A Tnpix Soft Body or a Tnpix Volume with a Channel above the Preserve lets go of the points it paints, as it does over a Tnpix Pin. Over a Tnpix Pin on the same point the Preserve wins; with two Preserves on one object each names its own channel, and where they overlap the larger paint counts. On a Tnpix Soft Body the preserved surface points hold and the flesh between them moves. A Tnpix Cache records the preserved points like every other point. A Preserve works the same on a Solver shared by several garments.

How it reads the animation

Each frame of the animation is taken when 3ds Max hands that frame to the Solver. Played in order from the first frame (with Real Time off), or recorded into a Tnpix Cache as the farm scripts do, every frame is exact. A frame 3ds Max never showed — after a jump ahead on the timeline — has no animation to read: the preserved points take the animation blended between the nearest frames that were shown, and the status line names those frames. Played from the first frame afterwards, they are simulated again on their own animation.

An edit to the animation below the Solver — a changed Skin, a moved key — is seen on the next play: the cloth simulates again on the edited animation.

Interface

Tnpix Preserve rollout

Enabled Default on: Switches this Preserve off without removing it. Off, the painted points are simulated like the rest of the cloth.
Channel / Refresh: Which painted channel follows the animation below the Solver. <none> means this Preserve holds nothing. A channel that is no longer on the stack is shown as missing: pick it again or restore the channel. Refresh reads the channel list from the stack again.
Status line: What the Preserve holds: how many points it preserves, how many of them sit on the animation and how many form the soft edge; and the frames whose animation was blended because 3ds Max never showed them.

The TenPix Graph shows a Preserve node with the same Enabled and Channel.

Self collision leaves out every triangle and edge that touches a point painted 1, so the ring of triangles around a preserved region lets other cloth through. Keep the hard edge of the paint where no other cloth has to rest on it.

A render farm job that simulates while it renders, instead of recording a Tnpix Cache first, reaches each task's first frame by a jump, and those frames are blended. Record the caches on the farm, as the TenPix farm scripts do (see Rendering on a Farm in Chapter 5).