Applying overlay materials into multi-surface meshes currently
requires adding a next pass material to all the surfaces, which
might be cumbersome when the material is to be applied to a range
of different geometries. This also makes it not trivial to use
AnimationPlayer to control the material in case of visual effects.
The material_override property is not an option as it works
replacing the active material for the surfaces, not adding a new pass.
This commit adds the material_overlay property to GeometryInstance3D
(and therefore MeshInstance3D), having the same reach as
material_override (that is, all surfaces) but adding a new material
pass on top of the active materials, instead of replacing them.
The built-in ALPHA in spatial shaders comes pre-set with a per-instance
transparency value. Multiply by it if you want to keep it.
The transparency value of any given GeometryInstance3D is affected by:
- Its new "transparency" property.
- Its own visiblity range when the new "visibility_range_fade_mode"
property is set to "Self".
- Its parent visibility range when the parent's fade mode is
set to "Dependencies".
The "Self" mode will fade-out the instance when reaching the visibility
range limits, while the "Dependencies" mode will fade-in its
dependencies.
Per-instance transparency is only implemented in the forward clustered
renderer, support for mobile should be added in the future.
Co-authored-by: reduz <reduzio@gmail.com>
For the time being we don't support writing a description for those, preferring
having all details in the method's description.
Using self-closing tags saves half the lines, and prevents contributors from
thinking that they should write the argument or return documentation there.
This commit adds the following properties to GeometryInstance3D: `visibility_range_begin`,
`visibility_range_begin_margin`, `visibility_range_end`, `visibility_range_end_margin`.
Together they define a range in which the GeometryInstance3D will be visible from the camera,
taking hysteresis into account for state changes. A begin or end value of 0 will be ignored,
so the visibility range can be open-ended in both directions.
This commit also adds the `visibility_parent` property to 'Node3D'.
Which defines the visibility parents of the node and its subtree (until
another parent is defined).
Visual instances with a visibility parent will only be visible when the parent, and all of its
ancestors recursively, are hidden because they are closer to the camera than their respective
`visibility_range_begin` thresholds.
Combining visibility ranges and visibility parents users can set-up a quick HLOD system
that shows high detail meshes when close (i.e buildings, trees) and merged low detail meshes
for far away groups (i.e. cities, woods).
Added an occlusion culling system with support for static occluder meshes.
It can be enabled via `Project Settings > Rendering > Occlusion Culling > Use Occlusion Culling`.
Occluders are defined via the new `Occluder3D` resource and instanced using the new
`OccluderInstance3D` node. The occluders can also be automatically baked from a
scene using the built-in editor plugin.
