Blender Git Loki

Cycles: First attempts at making OpenVDB modifier show up in render

OpenVDB: Added backwards compatibility with Tangent 2.78 builds.

Merge branch 'master_upstream' into luca_openvdb_import_28

Fixed split option UI for OpenVDB modifier

Fix volume not visible in render with "hide volume"

This fixes an issue that caused volumes to disappear in renders when the
"hide volume" or "hide uunselected" display options are enabled.

The issue was that the modifier is called prior to rendering, with the
"MOD_APPLY_RENDER" flag, as expected. However immediately after, and
while still rendering, the modifier is called again, without the render
flag, causing it to be recomputed as it should be for the viewport
display. This happens because Blender allows you to work while
rendering, and thus the display version of the modifiers has to be
computed.

The issue is of course that while this is not a problem for meshes, as
they are copied and passed along the modifier stack, data which is read
directly (such as volume data), is still subject to side-effects.

This commit prevents the modifier from updating the data while a render
is in progress, thus keeping the render data intact. This unfortunately
causes the minor side-effect of full resolution smoke being displayed in
the viewport after rendering, even when the "simplify" option is used.
Note however that this causes no extra data loading, and thus
performance is unaffected. Also note that the hiding options don't
suffer from this side effect, and so if the volume is hidden, it's
hidden state will still be in effect after the render, as hiding does
not rely on the cache being reloaded.

Fix mistake in VDB modifier UI code

When implementing the split grid channels and the velocity grids, I
forgot to update a bit of code in the UI. This fixes that issue.

Fix crashes and errors with internal smoke sims

Some special properties for VDB were causing Blender smoke sims to
crash.

Import OpenVDB velocity grids

This imports the OpenVDB velocity grid into Blender's own data
structure, making it available for rendering.

Fix OpenVDB start/end frame on copy

Start/end frames were being reset when copying the OpenVDB object.

Clean VDB UI a bit

Add flame display thickness to the VDB options

Add smoke display thickness to the VDB settings

Add voxel value display threshold options

VDB modifier now updates grids after file selection.

This is probably done in the wrong place, but better than nothing.

Fixed build without OpenVDB enabled.

Merge 'master' into 'luca_openvdb_import_28'

Merge 'master' into 'luca_openvdb_import_28'

Merge 'master' into 'luca_openvdb_import_28'

Fix crash when selecting things in other scenes

Any time a selection was attempted where the Base was NULL, Blender
wound segfault (distraction when adding the update hack for commit 8111d289)

Fix update bug when removing density grid

Removing density grid while having another grid assigned, did not cause
the density to disappear from the scene.