This adds the possibility to simulate things like red ears with strong backlight or material with high scattering distances.
To enable it you need to turn on the "Subsurface Translucency" option in the "Options" tab of the Material Panel (and of course to have "regular" SSS enabled in both render settings and material options).
Since the effect is adding another overhead I prefer to make it optional. But this is open to discussion.
Be aware that the effect only works for direct lights (so no indirect/world lighting) that have shadowmaps, and is affected by the "softness" of the shadowmap and resolution.
Technical notes:
This is inspired by http://www.iryoku.com/translucency/ but goes a bit beyond that.
We do not use a sum of gaussian to apply in regards to the object thickness but we precompute a 1D kernel texture.
This texture stores the light transmited to a point at the back of an infinite slab of material of variying thickness.
We make the assumption that the slab is perpendicular to the light so that no fresnel or diffusion term is taken into account.
The light is considered constant.
If the setup is similar to the one assume during the profile baking, the realtime render matches cycles reference.
Due to these assumptions the computed transmitted light is in most cases too bright for curvy objects.
Finally we jitter the shadow map sample per pixel so we can simulate dispersion inside the medium.
Radius of the dispersion is in world space and derived by from the "soft" shadowmap parameter.
Idea for this come from this presentation http://www.iryoku.com/stare-into-the-future (slide 164).
How to use:
- Enable subsurface scattering in the render options.
- Add Subsurface BSDF to your shader.
- Check "Screen Space Subsurface Scattering" in the material panel options.
This initial implementation has a few limitations:
- only supports gaussian SSS.
- Does not support principled shader.
- The radius parameters is baked down to a number of samples and then put into an UBO. This means the radius input socket cannot be used. You need to tweak the default vector directly.
- The "texture blur" is considered as always set to 1
Engine is not stored in WorkSpaces. That defines the "context" engine, which
is used for the entire UI.
The engine used for the poll of nodes (add node menu, new nodes when "Use Nodes")
is obtained from context.
Introduce a ViewRender struct for viewport settings that are defined for
workspaces and scene. This struct will be populated with the hand-picked
settings that can be defined per workspace as per the 2.8 design.
* use_scene_settings
* properties editor: workshop + organize context path
Use Scene Settings
==================
For viewport drawing, Workspaces have an option to use the Scene render
settings (F12) instead of the viewport settings.
This way users can quickly preview the final render settings, engine and
View Layer. This will affect all the editors in that workspace, and it will be
clearly indicated in the top-bar.
Properties Editor: Add Workspace and organize context path
==========================================================
We now have the properties of:
Scene, Scene > Layer, Scene > World, Workspace
[Scene | Workspace] > Render Layer > Object
[Scene | Workspace] > Render Layer > Object > Data
(...)
Reviewers: Campbell Barton, Julian Eisel
Differential Revision: https://developer.blender.org/D2842
Theses Materials are rendered after the SSR pass.
The only difference with previous method is that they have a depth prepass (less overdraw) and are not sorted.
For the moment the only way to enable this is to:
- enable Screen Space REFLECTIONS.
- enable Screen Space Refraction in the SSR parameters.
- enable Screen Space Refraction in the material tab.
This changes the Cycles exporting and Cycles/Eevee UI code to support both
output material nodes, giving priority to the renderer native one. Still
missing is Eevee code to prefer the Eevee output node.
Hashed Alpha transparency offers a noisy output but has the benefit of being correctly ordered. Noise can be attenuated with Multisampling / AntiAliasing.
This fixes an issue introduced by the new output node system, where "No
output node" was displayed in the material panel even when an output
node was present.
TexFace complicates the now more popular shading pipeline by having
per-face images, see: T51382 for details.
To keep the ability to select a per-material edit-image
(used with UV-mapping workflow), the material now stores an image
which will be set when changing images in edit-mode.
This is used as a bake-target when not using Cycles too.
- Use uniform color world for the world probe.
- Refactored the Fresnel expression to be better with Area Lights.
- Squared the roughness for default materials.
- Added New Batch cache routine to get the split mesh for each material. (optimization needed)
- Did some shader modifications to create default_frag and support a somwhat correct fresnel for lamps (to finish)
Although this wasn't so obvious since it
only showed up for factory settings and in the preferences window.
Panel display order depends on registration order,
Sorry for the noise. On the bright side we no longer need to move
classes around to re-arrange panels.
Also refactor:
- Material property UI related to shadows
- Preparation of OR-ed mode flags (ma->mode_l) of render materials
Reviewers: brecht
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D313
The "Cast Shadows" worked as expected, but it can cause problem in some cases.
For example, when using strand render, we need disabling only buffer shadows,
but the previous changes made that impossible. "Cast Shadows" should be added
as a newly created option.
This allows us to make materials that don't cast ray shadows.
Turning off this property can reduce the rendering time slightly.
Note: RNA path is changed to "use_cast_shadows" as well. The older
path "use_cast_buffer_shadows" still can be used as its alias, but
it will be removed after updating some addons.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D272
Notes:
* Did not touch to addons, that's up to the authors. ;)
* Did not removed any "name" field below lists. We might want to do this in some cases (less UI clutter), but probably not always, so will let maintainers of the related areas decide here.
Notes:
* Made those edits by full checking of py files, so I should have spoted most needed edits, yet it remains quite probable I missed a few ones, we'll fix if/when someone notice it...
* Also made some cleanup "on the road"!
(Did not add those when I created that module, because I did not thought we would actually need them in usual UI code, but turned out I was wrong).
Also made some optimizations in those py gettext funcs, when i18n is disabled at build time, no need to do pyobject -> cstring -> pyobject conversions!.
It introduces a new (py-extendable and registrable) RNA type, UIList (roughly similar to Panel one), which currently contains only "standard" list's scroll pos and size (but may be expended to include e.g. some filtering data, etc.). This now makes lists completely independent from Panels!
This UIList has a draw_item callback which allows to customize items' drawing from python, that all addons can now use. Incidentally, this also greatly simplifies the C code of this widget, as we do not code any "special case" here anymore!
To make all this work, other changes were also necessary:
* Now all buttons (uiBut struct) have a 'custom_data' void pointer, used currently to store the uiList struct associated with a given uiLayoutListBox.
* DynamicPaintSurface now exposes a new bool, use_color_preview (readonly), saying whether that surface has some 3D view preview data or not.
* UILayout class has now four new (static) functions, to get the actual icon of any RNA object (important e.g. with materials or textures), and to get an enum item's UI name, description and icon.
* UILayout's label() func now takes an optional 'icon_value' integer parameter, which if not zero will override the 'icon' one (mandatory to use "custom" icons as generated for material/texture/... previews).
Note: not sure whether we should add that one to all UILayout's prop funcs?
Note: will update addons using template list asap.
