Rendering Short Movies with VXAO
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Latest comments
3 hours ago

$16 for a *very* non-performant material? If this was intended for use in high-detail scenes, not meant for gameplay, one would generally just use a flipbook animation, or looping HD video texture (both of which are higher quality and available for free all over). I love options, but c'mon, that's pretty steep. $5, maybe. And you can loop in materials, using custom HLSL nodes. Also, there are better ways of doing this, all around. Somewhere on the forums, Ryan Brucks (of Epic fame) himself touched on this. I've personally been working on a cool water material (not "material blueprint", thankyouverymuch) and utility functions, and am close to the quality achieved here, sitting at ~180 instructions with everything "turned on". The kicker? It's pure procedural. No textures are needed. So this is cool, no doubt about that. In my humble opinion though, it's not "good". It doesn't run fast, and it's more complicated than it needs to be.

Lee is right - you can use a gradient effect when you vertex paint in your chosen 3d modelling platform (I've done it in max), meaning the wind effect shifts from nothing to maximum along the length of the leaf/branch/whatever.

by Lee Stojkovic
4 hours ago

I'm fairly certain you can vertex paint the bottoms of the foliage and control the movement using vertex colors along with the wind node. I did this in an earlier project and was able to create a scene with grass that moved less and less as it went down until stationary. I created the grass and painted the vertexes black to red (bottom to top) in Maya.

Rendering Short Movies with VXAO
26 April, 2016

Check out this recent post from Byzantos 3D, which takes on using VXAO. Developer renders out a short movie using this tech and then presents a breakdown of the production process.

Rendering Short Movies with VXAO


With all the earlier posts about VXAO, it’s time we put things together and render out a short movie that features this novel tech in all its glory. What better subject than (yet another!) forest? Forests are such a nice subject for exercises like this because they typically feature all the big and small objects crucial for testing whether one type of AO can cover most, if not all, essentials. For this reason I disabled Distance Field AO once again and tried to limit usage of any type of Screen Space AO to the least. The Kite Demo assets continue to prove their worth, although I added some which are mere modified versions of the excellent originals.

The Scene

A small, basic landscape with grass, heather, some flowers and 2 types of trees. Tiny objects are culled at a reasonable distance to keep enough performance. Object density is great and we’re able to get a lot of detail for some shots. Even the fallen leaves are made of geometry although that might have been a tad overkill. As mentioned above, some modified objects were used, primarily to get some better density in tree canopies. I was curious what effect this would yield but the results ended up a bit too contrast-rich. If I’d do things over, I probably would use the same lighting as some of the more ‘ambient lit’ shots show.

Rendering Short Movies with VXAO

Rendering Short Movies with VXAO


A Direct Light with Ray Traced Distance Field Shadows and a Skylight with a HDRI cubemap. Intensity varies per shot. The Post-Processing volume is mainly used to get a good variety of VXAO settings in terms of range, strength and size per shot. Some close-ups feature a bit of HBAO+.

Rendering Short Movies with VXAO

Rendering Short Movies with VXAO


VXAO does not impact performance nearly as much as the object count. With so many small meshes and textures with transparency there’s bound to be a ton of overdraw and this eats away our framerate. We average around 20-25 fps. I did do some optimization tests and found that, by cutting out half the small nitty-gritty, framerate stabilized at 40 fps.

Rendering Short Movies with VXAO

Rendering Short Movies with VXAO


I rendered about a dozen individual clips with an average length of 10-12 seconds at 60fps and 200% Temporal AA as .jpg sequences. Rendering a single clip took about 3-5 minutes. The clips were then blended together in After-Effects. No other post-processing was applied, neither to the movie nor images.

Rendering Short Movies with VXAO



Speedtree wind is somewhat of a struggle to get right. It seems there’s a ‘warmup’ stage and, to make things worse, the wind effect you see in the editor is nothing like the effect which ends up in your renders. This makes setting up wind a full trial and error experience and the results are a bit lackluster.

Rendering Short Movies with VXAO

Rendering Short Movies with VXAO

Closing thoughts

I had a really good time experimenting with VXAO. It’s a pleasure to use and, although I still struggle with a lot of things in Unreal Engine 4, I’ll continue to find new ways to use it where it will improve my scenes. Even after testing a number of possibilities, it continues to surprise me, both in quality and stability.

Source: Byzantos 3D





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