Adjust Decal Height
shortcut da (with one object selected)
The default Midlevel value of the displace modifier used on decals is '0.9999'. For convenience this is displayed as '0' in the On Screen Display of the modal Adjust Decal Height tool.
Note
Blender displays the '0.9999' value as 1.000 in the modifier panel, but this rounding is only for UI purposes.
Sometimes the default '0.9999'/'0' value does not sufficiently offset a decal from the surface below and can produce artifacts, either due to overlapping decals using the same Midlevel values or due to intersecting geometry sometimes caused by triangulation of curved geometry.
In either case you can use Adjust Decal Height to quickly change the Decal height accordingly.
Select a Decal, start the tool and move the mouse left or right. You can press LEFTMOUSE or SPACE to confirm a new height and you can abort by pressing ESC or RIGHTMOUSE.
You can use SHIFT for finer control and CTRL for bigger steps. You can jump to specific values using Y, X and C.
Tip
Keep the height as small as possible. Shadows will never be a problem as shadow casting is turned off for decals, but reflections appearing like shadows can creep in rather quickly when the height is increased. Those reflections can be turned off using the Glossy Rays extra option per decal as well as globally for all decals.
Change Panel Width
shortcut dc
Any panel decal's width can be changed after it has been 'cut' - using the Change Panel Width tool.
Tip
One of the many benefits of working with decals, is the simplicity of decal geometry. This means even edits of panel decals beyond changing the width are trivial: Panel decals can be modified using basic modeling techniques to change flow and direction, to round corners. Decals can be cut, masked and elongated with or without stretching, etc.
Extract Source
shortcut de
At any point in time you can bring back source objects.
Source objects for Decal Projections are the original flat, single-quad decals.
Source objects for Decal Slice, Decal Knife and Material Decals are the 'cutting' objects used in the creation of those decals.
You can always bring back those sources, even if you have brought back and deleted them. They remain in the blend file - hidden away so as to not clutter the scene - and remain accessible, as long as the projected, sliced, knifed or material decal are present in the scene.
Properties
Remove Decal
If checked, removes the decal, you are extracting the cuttting object from.
Reconstruct Panel Cutter
shortcut dr
An cases where Extact Source doesn't work, such as panel decals created via Draw Slice or complex panel decals, joined together from multiple individual ones, Reconstruct Panel Cutter can be used. It requires the panel decal to be an all-quad strip and will create a mesh, that perfectly intersects at the center line of the panel decal.
This the cutter can then be used with the Material Cut or Material Decal tools.
Properties
Cutter Depth
Sets the height of the cutter, both in positive and negative.
Hide Panel Decal
if enabled, hides the panel decal you are reconstructing a cutter from.
Rotate Decal
shortcut ctrl+alt+shift + mouse wheel down (CW)
shortcut ctrl+alt+shift + mouse wheel up (CCW)
Using Rotate Decal you can quickly rotate decals(or any other object) around the local Z axis clockwise or counter clockwise.
If you go into edit mode or to the Image/UV editor, you can also quickly rotate UVs using the same shortcuts. This is helpful for correcting wrongly aligned panel UVs, but also for rotating already projected decals.
Note
There's no pie menu representation for Rotate Decal, it's only accessible through shortcuts(or the spacebar menu).
Properties
Axis
Choose the Axis to rotate around. Defaults to Z. Only available in Object mode.
Angle
The Angle a Decal is rotated by. It's set to 45 by default, but can take arbitary values. Keep in mind however, that the angle is reset back to 45 degrees everytime you run Rotate Decal. Furthermore, the angle is always 90° when rotating UVs in edit mode.
Material Cut
shortcut dm
Material Cut has the same purpose as Material Decal. However it is intended more as a finalizing tool, if you want to export your model. Material Cut will cut new edges into your target geometry, delimiting an area of polygons you can then apply a material to. To facilitate quick selection using Linked, the newly cut edges are maked as Seams by default.
Note
Due to the nature of Material Cut, there's currently no way to extract the source, hence why you should use Material Decal, while designing. You can then come back later and do Material Cuts using the sources extracted from Material Decals.
Properties
Merge Parts
If checked, the vertices of the newly cut edges are merged. If unchecked, the newly cut geometry will be separate and unconnected. Increase the threshold value to remove unwanted duplicate verts that may appear on the material cut.
Mark Seams
If active, the newly cut edges will be marked as Seams. This facilities easy selection using Select Linked to quickly assign a new material.
Mark Freestyle
If checked, the newly cut edges will be marked as Freestyle. This may be used to mark the edges, without influencing the UVing process, which Seams do. You can use the Convert Freestyle to Seam and Convert Seam to Freestyle tools(space bar menu) to convert between Seam and Freestyle.
Turn on Wire
If enabled, the cut object will automatically set to display the wireframe, thereby making the new cuts visible in object mode.
(V)Match Material
shortcut dv
The materials of all four decal types can of course be edited manually in the node editor. In many cases however, all you want to do is match a decal to an existing material, usually the one a decal sits on top of.
The Match Material tool can be used to match Subtractor, Subset or Panel Decals to a target object's material. Info Decals can not be matched.
Note
Materials with the Principled BSDF or the Glossy BSDF shader or supported. Understand, that any nodes connected to the inputs of those shaders will be ignored. Keep it to simple parameter based materials.
Subset Decals and Panel Decals are a mix of two materials. This is done so the internal(Subset) and exteral(Material) parts or both sides of a Panel Decal can be edited independently from each other.
Subtractor Decals naturally only have a single Material part.
Keep in Mind
Keep the Update Decal Nodes tools in mind when working on scenes created with DECALmachine versions before 1.4.1.
Properties
Material Slot
Select the Material Slot of the target object you want to match. Just step through the values if you are not sure in what slot a material is sitting in.
Match Material
If checked the Material part of the Decal will be matched. In Subset Decals that's the outer part.
Match Subset / Match Second Side
If checked Match Subset matches the outer part of a Subset Decal. In Panel Decals it's called Match Second Side. Note that DM avoicds creating duplicate Materials and in the case of Panel Decals and existing Material may be applied that is flipped. In that case use the Panel Flip tool.
Init Base Material
shortcut di
Init Base Material will remove all pre-existing materials and material slots of the selected objects. If there is no 'base' material in the scene, one will be created, otherwise, the existing base material will be used. The base material is then applied to all objects in the selection.
Internally, Init Base Material is also used by Decal Project and Decal Slice, however when called by these tools, it won't remove pre-existing materials.
The created base material describes a plain grey, metallic surface. Since Blencer 2.79 a Principled BSDF shader will be used.
Panel Unwrap
shortcut dp (with one panel decal selected)
After you have edited panel decal geometry by hand, the decal will almost always need to have its UVs redone. To do so, run Panel Unwrap from edit or object mode.
The unwrapping is LENGTH based, meaning a long face, will also be long in UV space, and a short one will be short accordingly. This allows for regular repeating patterns in panel decals.
Tip
If you run Panel Unwrap from edge mode with an edge selected you can determine where the UV strip ends/begins. Usually, that's nothing you need to be concerned about, but it's good to know.
Note
Panel Unwrap requires the decal strip to be all quad. If there are tris or n-gons in the panel strip or the panel strip is not joined properly, UVs created by Panel Unwrap may include mixed orientations and as aresult not display as expected.
I recommend using MACHIN3tools Cleans Up Good to quickly find and select unwanted tris and n-gons.
In some rare cases, Panel Unwrap will lay out the UVs vertically, as opposed to horizontally as they need to be. If this happens, you need to rotate the strip UVs 90° using the Rotate UVs property or by using the Rotate Decal tool.
Properties
Rotate UVs
Rotates panel strip UVs by 90 degrees, used to fix the occasional faulty UVs in panel strips.
Panel Flip
shortcut df
In some cases Material Matching a Panel Decal will produce the inverse result of what was intended. Just flip the panel to solve this.
Tip
You can also use Rotate Decal to rotate UVs in two 90 degree steps and so achieve the same result. Flipping will be quicker however.
Panel Transition
shortcut dp (with two panel decals selected)
You may want to have some panel decals run into or cross each other. To make this render nicely, even when seen up close, you need to edit the panel strips in a specific way.
Panel Transition does the main work for you here, but you still need to manually slide - with Correct UVs enabled - some vertices into place.
Tip
You can get away with a lot and you actually don't need to do any of this, if you don't have close up shots.
If you plan to export your model, say to take it into a deferred renderer, you may want to merge your panel geometry accordingly.
While working on the design, it's best to keep all panel decal strips separate, to ensure a maximum of flexibility and editability and to keep Change Panel Width working as expected.
Note
If Panel Unwrap is run after the vertices at the end of a panel strip have been slid in place, you need so scale these vertices closer together in UV space as well.