https://wiki.blender.jp/index.php?action=history&feed=atom&title=%E5%88%A9%E7%94%A8%E8%80%85%3AKevindietrich%2FOpenVDBRendering利用者:Kevindietrich/OpenVDBRendering - 版の履歴2026-04-26T15:45:19Zこのウィキのこのページに関する変更履歴MediaWiki 1.31.0https://wiki.blender.jp/index.php?title=%E5%88%A9%E7%94%A8%E8%80%85:Kevindietrich/OpenVDBRendering&diff=149711&oldid=prevYamyam: 1版 をインポートしました2018-06-28T21:13:59Z<p>1版 をインポートしました</p>
<table class="diff diff-contentalign-left" data-mw="interface">
<tr class="diff-title" lang="ja">
<td colspan="1" style="background-color: #fff; color: #222; text-align: center;">← 古い版</td>
<td colspan="1" style="background-color: #fff; color: #222; text-align: center;">2018年6月28日 (木) 21:13時点における版</td>
</tr><tr><td colspan="2" class="diff-notice" lang="ja"><div class="mw-diff-empty">(相違点なし)</div>
</td></tr></table>Yamyamhttps://wiki.blender.jp/index.php?title=%E5%88%A9%E7%94%A8%E8%80%85:Kevindietrich/OpenVDBRendering&diff=149710&oldid=prevwiki>Kevindietrich: /* Ray intersections */2015-07-05T06:13:37Z<p><span dir="auto"><span class="autocomment">Ray intersections</span></span></p>
<p><b>新規ページ</b></p><div>= OpenVDB Volume Rendering =<br />
<br />
This project aims at integrating OpenVDB in Cycles.<br />
<br />
== First results ==<br />
<br />
[[{{ns:6}}:Dev-cycles-openvdb-render-explosion.png|300px]]<br />
[[{{ns:6}}:Dev-cycles-openvdb-render-smoke1.png|300px]]<br />
<br />
== Grids ==<br />
<br />
Grids are currently loaded from files, just like image textures. No assumptions is made on the number of grids present in a given file, or their names, so that any scalar or vector grid (actually "FloatGrid" and "Vec3SGrid") contained in the file will be accessible in the shading context. This also makes it possible to render files exported from other software, though in this case there will most likely be a mismatch between the other software's and Blender's unit system.<br />
<br />
Here is an example file setup to render fire.vdb available at the [http://www.openvdb.org/download OpenVDB website]: [[File:Cycles_openvdb_fire.blend]].<br />
Note: fire.vdb needs to be downloaded separately.<br />
<br />
== Sampling ==<br />
<br />
Sampling is done by means of grid samplers (openvdb::tools::GridSampler) making of value accessors (openvdb::tree::ValueAccessor) for accelerated (cached) tree traversal.<br />
<br />
The following samplers are implemented:<br />
* point: performs nearest neighbor interpolation, fast<br />
* box: performs trilinear interpolation, slower but prettier<br />
<br />
== Ray intersections ==<br />
<br />
If the grid's voxels are uniform, ray intersection and volume marching is performed with OpenVDB's built-in ray intersectors. By making use of a custom hierarchical digital differential analyzer, they help skipping empty space by leap frogging inactive tiles and values. Its hierarchical nature makes it so that leap frogging happens at any level of the tree (from upper nodes down to individual voxels).<br />
<br />
== Shortcomings ==<br />
<br />
* Compilation with OSL is not supported.<br />
<br />
== ToDos ==<br />
<br />
* file sequences are not updated during viewport rendering.<br />
* support for ray marching multiple volumes.<br />
* decoupled ray marching support</div>wiki>Kevindietrich