Add a new shader node to control volume coefficients (scattering,
absorption and emission) directly, making it easier to model existing
volumes with measured data.
Pull Request: https://projects.blender.org/blender/blender/pulls/136287
The issue here is that the automatic bump shader in OSL adjusts globals.N,
which is used to define each closure's shading normal, but sd->N remains
as it was (unlike SVM, which sets it from svm_node_set_normal).
This is a problem since some code like the shadow terminator stuff uses sd->N,
so to make behavior consistent the fix is to set it from OSL as well.
Pull Request: https://projects.blender.org/blender/blender/pulls/138092
osl_transform_triple(), osl_transform_dvmdv() and so on are supposed to apply
the given transform in the context of OSL's auto-differentiation system.
Therefore, the given input is a dual vector, containing both the value as v[0]
and its derivatives w.r.t. X and Y in v[1] and v[2].
However, the existing code treats these as a simple list of vectors, applying
the same operation to all three instead of propagating the derivatives.
On top of that, it also treated the given matrix input as if there were three
of them, which isn't the case.
Therefore, this commit replaces the implementation to do the right thing.
The Vector and Normal case are straightforward since the operation is linear,
so applying the same operation to all three vectors works.
The Point case is a bit more complicated, but not too bad when written out.
This bug mostly became apparent when using Object or Camera texture coordinates
with a Bump node, since that node uses OSL differentials and Object/Camera
coordinates are implemented using transform().
I'm pretty sure that all the other builtin functions (e.g. sin) at the bottom
of services_gpu.h have the same problem, but one thing at a time...
Pull Request: https://projects.blender.org/blender/blender/pulls/138045
This allows users to implement arbitrary camera models using OSL by writing
shaders that take an image position as input and compute ray origin and
direction.
The obvious applications for this are e.g. panorama modes, lens distortion
models and realistic lens simulation, but the possibilities are endless.
Currently, this is only supported on devices with OSL support, so CPU and
OptiX. However, it is independent from the shading model used, so custom
cameras can be used without getting the performance hit of OSL shading.
A few samples are provided as Text Editor templates.
One notable current limitation (in addition to the limited device support)
is that inverse mapping is not supported, so Window texture coordinates and
the Vector pass will not work with custom cameras.
Pull Request: https://projects.blender.org/blender/blender/pulls/129495
Use VERBATIM to ensure spaces inside command line arguments don't get
escaped automatically.
On Linux and Windows the oneAPI kernel compilation still has problems.
There is an apparent bug with single quote escaping in add_custom_command
which means it's not easy to use VERBATIM.
This makes it possible to restore previous Blender 4.3 behavior of bump
mapping, where the large filter width was sometimes (ab)used to get a bevel
like effect on stepwise textures.
For bump from the displacement socket, filter width remains fixed at 0.1.
Ref #133991, #135841
Pull Request: https://projects.blender.org/blender/blender/pulls/136465
There is code that properly handles panoramic cameras in
`camera_world_to_ndc`, the transform matrices (e.g.
`OSLRenderServices::get_inverse_matrix`) in the `transform("NDC", P)`
call dont do the "full work" here (maybe they should though?).
But we can get to `camera_world_to_ndc` by just getting the "NDC"
attribute, so use that for now.
Pull Request: https://projects.blender.org/blender/blender/pulls/136097
* Add SubdAttributeInterpolation class for linear attribute interpolation.
* Dicing computes ptex UV and face ID for interpolation.
* Simplify mesh storage of subd primitive counts
* Remove kernel code for subd attribute interpolation
* Remove patch table packing and upload
The old optimization adds a fair amount of complexity to the kernel, affecting
performance even when not using the feature. It's also not that useful as it
does not work for UVs that needs special interpolation. With this simpler code
it should be easier to make it feature complete.
Pull Request: https://projects.blender.org/blender/blender/pulls/135681
This implements three improvements to the energy preservation and albedo
scaling logic, which help the Principled BSDF pass the white-furnace test
when using the coat layers at high roughness.
Specifically, at roughness 0.3, the albedo scaling brings it from 60% at
the edge to 95%, and with the energy preservation it's 99.8%.
Pull Request: https://projects.blender.org/blender/blender/pulls/134620
This is an intermediate steps towards making lights actual geometry.
Light is now a subclass of Geometry, which simplifies some code.
The geometry is not added to the BVH yet, which would be the next
step and improve light intersection performance with many lights.
This makes object attributes work on lights.
Co-authored-by: Lukas Stockner <lukas@lukasstockner.de>
Pull Request: https://projects.blender.org/blender/blender/pulls/134846
The attribute handling code in the kernel is currently highly duplicated since
it needs to handle five different data types and we couldn't use templates
back then.
We can now, so might as well make use of it and get rid of ~1000 lines.
There are also some small fixes for the GPU OSL code:
- Wrong derivative for .w component when converting float2/float3->float4
- Different conversion for float2->float (CPU averages, GPU used to take .x)
- Removed useless code for converting to float2, not used by OSL
Pull Request: https://projects.blender.org/blender/blender/pulls/134694
The issue here is that the individual components of TypeDesc are 8-bit each,
but the code was applying a 4-bit mask. It just so happens that the only
case where this matters is TypeDesc::MATRIX44, since its value is 16.
In Cycles lights can be given a light falloff node to control their
light falloff.
This worked by multiplying the light's strength by different
combinations of the ray length, which would be FLT_MAX for
distant lights. This resulting in almost every configuration of the
light falloff node overflowing when used on distant lights, which is
undesirable.
This commit fixes this issue by ignoring most of the functions of the
light falloff node when used on a distant light.
And in the process fixes a small discrepancy between SVM and OSL when
using the light falloff node on distant lights.
Pull Request: https://projects.blender.org/blender/blender/pulls/134539
This commit fixes a issue where ray depth for emissive objects
(E.g. Lights) was incorrect when using the ray depth output of the
light path node in Cycles OSL.
Pull Request: https://projects.blender.org/blender/blender/pulls/134496
This commit adds the `light:random` attribute to OSL, allowing the
object info node to now match between SVM and OSL when using the
random output on a light.
Pull Request: https://projects.blender.org/blender/blender/pulls/134095
The derivatives of the normal were simply not computed.
The offsetted normals are computed by perturbating the barycentric
coordinates. At triangle boundaries, the normals are extrapolated,
so discontinuities might be visible.
Currently only supported on triangles.
Pull Request: https://projects.blender.org/blender/blender/pulls/133769
Use sub-pixel differentials for bump mapping helps with reducing
artifacts when objects are moving or when textures have high frequency
details.
Currently we scale it by 0.1 because it seems to work good in practice,
we can adjust the value in the future if it turns out to be impractical.
Ref: #122892
Pull Request: https://projects.blender.org/blender/blender/pulls/133991
That version has a bunch of API changes, so by dropping support for older
versions we can remove old compatibility code.
Also, that version is required for OptiX support, so building a fully-featured
Cycles wasn't possible with older OSL anyways.
Pull Request: https://projects.blender.org/blender/blender/pulls/133746
OSL has OSL::ShaderGlobals, which contains all the state for OSL shader
execution. The renderer fills it out and hands a pointer to OSL, and any
callbacks (e.g. for querying attributes) get the pointer back.
In order to store renderer-specific data in it, there's a few opaque pointers
in the struct, but using those has led to a mess of reinterpret_cast<> and
pointer indirection in order to carry all the data around.
However, there is a way to do this nicer: Good old C-style struct inheritance.
In short: Unless you're doing pointer arithmetic, you can just add additional
data at the end of a base struct, and the rest of the code won't care.
In this case, this means that we can have our own ShaderGlobals struct and
add more Cycles-specific data at the end. Additionally, we can replace the
generic opaque void pointers with ones of the correct type, which saves us
from needing to cast them back.
Since we have a copy of ShaderGlobals for GPU OSL anyways, it's just a matter
of refactoring the code a bit to make use of that.
The advantages of this are:
- Avoids casts all over the place, just needs one cast to turn our
ShaderGlobals into the "base" type that OSL expects and one to turn the
pointer that OSL gives us on callbacks back into our "derived" type.
- Removes indirection, all the relevant stuff (sd, kg, state) is now
directly in the ShaderGlobals
- Removes some OSL-specific state from ShaderData, which helps to keep
memory usage down
Pull Request: https://projects.blender.org/blender/blender/pulls/133689
The oren_nayar_diffuse_bsdf closure in OSL had two issues:
- It broke when used with roughness of zero
- It only used the provided albedo for energy compensation, so it still
required the user to multiply with the albedo
Therefore, this handles the zero roughness corner case and includes
the albedo in the closure weight.
This makes no difference when using the closure through the Diffuse
or Principled BSDF nodes, only for custom OSL shaders.
Pull Request: https://projects.blender.org/blender/blender/pulls/133597
The `ZDepth` output of the camera data node was different between SVM
and OSL.
SVM would output the `ZDepth`, with negative distances for points
behind the camera. While OSL would output the absolute of the distance,
which resulted in points behind the camera becoming positive.
Align OSL to SVM and allow outputting the negative distance as it
allows users to differentiate between what's in front or behind the
camera.
Pull Request: https://projects.blender.org/blender/blender/pulls/132837
Check was misc-const-correctness, combined with readability-isolate-declaration
as suggested by the docs.
Temporarily clang-format "QualifierAlignment: Left" was used to get consistency
with the prevailing order of keywords.
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
* Use .empty() and .data()
* Use nullptr instead of 0
* No else after return
* Simple class member initialization
* Add override for virtual methods
* Include C++ instead of C headers
* Remove some unused includes
* Use default constructors
* Always use braces
* Consistent names in definition and declaration
* Change typedef to using
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
