Decalmachine

Please see decal.machin3.io for extensive and up-to-date documentation.

Installation

I have no idea how to install this, how is it done?

See the Installation guide and follow it precisely.

Other Addons

Is HardOps or BoxCutter required?

HardOps and BoxCutter are not needed to use DECALmachine. That said, HOps/BC and DM fill different niches. DM is a finishing and detailing tool. While HOps/BC are tools for working with form and generally improve the Blender experience greatly.As such the addons complement each either very well and work great in tandem.

Furthermore it should be noted, that the HardOps and BoxCuter developers have been and continue to be extremely supportive and helpful and DECALmachine would not be what it is, without their contributions and guidance.

Is the Asset Management addon required?

Since version 1.2. DECALmachine has its own asset loader, made possible through HardOps tech being graciously shared, and so Asset Management no longer adds a benefit in terms of bringing decals into the scene.

For all other importing needs(meshes, light setups, materials, etc) I personally still heavily depend on Asset Management and would recommend it to anyone.

Technique

Can you bake the decal normal maps to a single normal map?

Out of the box, you can't, there's no support for it yet. That said, aMars on blenderartists has done it using xNormal. Also, Prime8 on polycount suggests it is possible in Blender itself.
I will investigate both of these routes, it looks promising.

For now it's pretty laborious work, as it requires manual decal atlas creation and adjustment of decal UVs to fit the atlas textures accordingly.

With the 1.4 release, which will focus on exporting decal geometry and textures, this process should be simplified and ideally completely automated.

Keep in mind however, that in regards to real time content, the whole point of using decals - in combination with custom/weighted vertex normals - is to stop relying on baked normal maps. The idea is to take the decal geometry into the engine and by utilizing deferred rendering techniques, have the mesh-based decals contribute to the textures of the underlying base mesh.
This is done very successfully and prominently in Star Citizen and Alien Isolation and this is the workflow DECALmachine is aiming at.

For now, the initial release of DECALmachine should be seen as a design tool inside Blender.

How do you export the decals to Unity/Unreal?

There's no export tool with the current 1.3.5 version. You can do it manually, but it's laborious work, as it requires manual decal atlas creation and adjustment of decal UVs to fit the atlas textures accordingly.

1.4 will be the export release and is actively being worked on. Among other things, it will feature automatic atlas creation and auto UV alignment to the atlas.

Is there a way to make decals affect displacement instead of normals?

Technically it's trivial to change the decal node tree to do displacement as the height maps are already supplied. But think about it, a floating decal with actual displacement?
First off, the decal would need to be subdivided a lot, which can be done, but secondly what would happen to the displaced geometry? It would intersect with the base mesh the decals are floating above - you wouldn't see much of the displaced geometry, as it is sunk into the base mesh.

What you could do in theory is bake down the height map of the decals to the basemesh and then use that baked height map, without the decals for displacement.

Using DECALmachine

How do I bring Decals into the scene? Why are the asset loaders missing, when I press the `d` key?

The asset loaders only show with nothing else selected. Context is important. Space in the pie is tight and most of the other tools already require the proper selection to be made, before they show up. If you have anything selected, press a to deselect followed by d to open the DECALmachine pie menu with the asset loaders.

Why are Decal Project, Decal Slice etc. missing from the pie menu?

Context is important. Select the decal, then the object you want to project on. Then open the pie by pressing d.
Similarly, select one object, then another one to decal slice.

How can I add/create my own Decals to the library?

There are currently two ways to create custom decals:

Instant Decal creation
Batch Decal creation

Make sure you have an up-to-date version installed and see the Custom Decal Creation guide.

How do I snap decals to a surface?

When Decals are imported using the asset loaders, all snap settings are prepared - face snapping, align to surface, etc. Snapping itself is not turned on however. The suggested method to move decals and align them is by holding down CTRL while moving decals via g. This will turn on snapping temporarily for as long as you hold down CTRL.

Why are decals just empty planes?

First, confirm the issue is occuring with the sample blend files in DECALmachine/assets/samplesRender the sample scenes using the shift+ z shortcut.

If it isn't happening in the sample scenes, but is happening in your own scenes:

make sure you have set the renderer to Cycles
make sure you have set the Viewport Shading to Material

If it's also happening in the sample scenes, get in touch.

When I taper panel decals for a panel transition, the texture get's distorted! What is going on?

You need to enable Correct UVs in the slide tool's properties - either in the T panel or by pressing F6.

Decal Slice is not working! What am I doing wrong?

Decal Slice is heavily depended on topology, so where the cutter intersects the target mesh is extremely important.
Also, the bigger the Panel Width Value is and the denser the target mesh is, the more likely it is for Decal Slice to fail.

The reason it fails is due to intersection of edges at odd angles, it wasn't able to create a quad-only panel strip and so the auto-UVing fails. You have two options in that case:

carefully position your cutter (turn wireframes on) and avoid troublesome intersections
lower the Decal Panel Width value

If it still fails no matter what you do, take the panel strip you get, fix it up - make it all quad - and run Panel Unwrap.

If you've used HardOps or Booleans in general, you know that you can't arbitrarily cut curved geometry without regards to the underlying topology and expect it to work perfectly.

There will be a second slice tool in the 1.4 release, which produces all quad strips guaranteed, but at the expense of not being as close to the base mesh, as it doesn't follow the topology.

Decal Creation

How do I create Info Decals?

Instant Decal creation turns geometry - as opposed to textures - into decals, so for Info Decals use the Batch Decal process instead, even if you have just one image to turn into a decal.

Errors

PermissionError: … Permission denied: 'C:\\Program Files\\… paneling.json'

You didn't install the addon to the user scripts folder, but in 'Program Files' instead. Review the Installation guide and follow it precisely.

OSError [Errno 30] Read-only file system: '... paneling.json'

You didn't install the addon to the user scripts folder, but into the blender.app package instead. Review the Installation guide and follow it precisely.

ImportError: No module named PIL

You didn't extract the PIL archive for your operating system or didn't move it to the modules folder. Review the Installation guide and follow it precisely.

ImportError: DLL load failed

If you are seeing this error on Windows when activating the addon, you need to install Microsoft Visual C++ Redistributable 2015

ImportError: Cannot import name _imaging