This introduces a new depsgraph API for getting updated datablocks,
rather than getting it from bpy.data.
* depsgraph.ids_updated gives a list of all datablocks in the depsgraph
which have been updated.
* depsgraph.id_type_updated('TYPE') is true if any datablock of the given
type has been added, removed or modified.
More API updates are coming to properly handle multiple depsgraphs and
finer update granularity, but this should make Cycles work again.
This patch adds support for IES files, a file format that is commonly used to store the directional intensity distribution of light sources.
The new IES node is supposed to be plugged into the Strength input of the Emission node of the lamp.
Since people generating IES files do not really seem to care about the standard, the parser is flexible enough to accept all test files I have tried.
Some common weirdnesses are distributing values over multiple lines that should go into one line, using commas instead of spaces as delimiters and adding various useless stuff at the end of the file.
The user interface of the node is similar to the script node, the user can either select an internal Text or load a file.
Internally, IES files are handled similar to Image textures: They are stored in slots by the LightManager and each unique IES is assigned to one slot.
The local coordinate system of the lamp is used, so that the direction of the light can be changed. For UI reasons, it's usually best to add an area light,
rotate it and then change its type, since especially the point light does not immediately show its local coordinate system in the viewport.
Reviewers: #cycles, dingto, sergey, brecht
Reviewed By: #cycles, dingto, brecht
Subscribers: OgDEV, crazyrobinhood, secundar, cardboard, pisuke, intrah, swerner, micah_denn, harvester, gottfried, disnel, campbellbarton, duarteframos, Lapineige, brecht, juicyfruit, dingto, marek, rickyblender, bliblubli, lockal, sergey
Differential Revision: https://developer.blender.org/D1543
The Math node currently has the normal atan() function, but for
actual angles this is fairly useless without additional nodes to handle the signs.
Since the node has two inputs anyways, it only makes sense to add an arctan2 option.
Reviewers: sergey, brecht
Differential Revision: https://developer.blender.org/D3430
The implementation is pretty straightforward.
In Cycles, sampling the shapes is currently done w.r.t. area instead of solid angle.
There is a paper on solid angle sampling for disks [1], but the described algorithm is based on
simply sampling the enclosing square and rejecting samples outside of the disk, which is not exactly
great for Cycles' RNG (we'd need to setup a LCG for the repeated sampling) and for GPU divergence.
Even worse, the algorithm is only defined for disks. For ellipses, the basic idea still works, but a
way to analytically calculate the solid angle is required. This is technically possible [2], but the
calculation is extremely complex and still requires a lookup table for the Heuman Lambda function.
Therefore, I've decided to not implement that for now, we could still look into it later on.
In Eevee, the code uses the existing ltc_evaluate_disk to implement the lighting calculations.
[1]: "Solid Angle Sampling of Disk and Cylinder Lights"
[2]: "Analytical solution for the solid angle subtended at any point by an ellipse via a point source radiation vector potential"
Reviewers: sergey, brecht, fclem
Differential Revision: https://developer.blender.org/D3171
Increasing the samplig dimensions like this is not optimal, I'm looking
into some deeper changes to reuse the random number and change the RR
probabilities, but this should fix the bug for now.
This save a little memory and copying in the kernel by storing only a 4x3
matrix instead of a 4x4 matrix. We already did this in a few places, and
those don't need to be special exceptions anymore now.
This is in preparation of making Transform affine only, and also gives us
a little extra type safety so we don't accidentally treat it as a regular
4x4 matrix.
around the volume.
We generate a tight mesh around the active voxels of the volume in order
to effectively skip empty space, and start volume ray marching as close
to interesting volume data as possible. See code comments for details on
how the mesh generation algorithm works.
This gives up to 2x speedups in some scenes.
Reviewed by: brecht, dingto
Reviewers: #cycles
Subscribers: lvxejay, jtheninja, brecht
Differential Revision: https://developer.blender.org/D3038
