Monthly Archives: August 2013

Commonly Ignored Feature #6: Dirty Vertex Colours

Modeled by 1DInc

Modeled by 1DInc

It’s a sort of quick, and fake ambient occlusion that you bake into the vertex colours of a mesh. It’s a little different from AO as it also gives some highlights on sharp edges.

2013-08-06_19-06-552013-08-06_19-07-04

Simply pop into vertex paint mode by hitting ‘V’ and run Dirty Vertex Colors from the Paint menu:

2013-08-06_19-11-16There’s a couple options you can play with in the toolbar (or by hitting F6) though the Highlight and Dirt Angle options don’t seem to be particularly intuitive.

To use these colours in Cycles, just add an Attribute node with the name of the vertex colour layer (“Col” by default).

2013-08-06_19-16-24

If that material is used by other objects, don’t forget to add Dirty Vertex Colors to those ones too, or just make a plain white colour layer, otherwise it’ll just be black.

 

PS: The image at the top takes roughly 2 hours per frame… I’ve been rendering it on and off for months now

 

Don’t Ask

Don't Ask

A little weekend doodle. I decided to take a break from work on Sunday, a day off. It felt good for once, and I figured I could finish my current freelance job before the deadline without working at all on Sunday.

Monday morning at 11 AM, the electricity goes out.
It only came on late today and now I’m in a mad panic to get this job done in time o/

Commit 58930: OSL performance increase

Just from the mailing list, OSL texture performance has been improved be 10-25%

Hi fellow cyclists,

I did a little experiment to try and improve the performance of cycles/OSL in scenes that use image textures. I tested the Barcelona scene from ba.org and tried a bit of an ugly hack to cache the OIIO perthread info.

I only have an ancient macbook pro here with me on holiday and would need to investigate further but initial results are a ~ 15% improvement on overall render time on this scene.

I expect the improvement to be bigger for machines with more cores but I cannot test that from here.

I attached the patch

-Martijn Berger

It may only have such a big performance for OSX, though probably at least a little for Windows and Linux

Commonly Ignored Feature #5: Using multiple UV maps

uvs

Unfortunately the Texture Coordinate node only gives us the active UV map (as indicated by the highlighted camera icon) and gives us no way of choosing which UV map we want.

Luckily we have the Attribute node. Simply enter the name of the UV map you want and connect the Vector output to anything you like to use those coordinates.

attributeuvs

That’s it. Yeah a short and quick CIF this weekend, I’ve got a tight deadline and am fighting bugs… more on that later.

Killing Caustics Cleverly

Alliteration aside, this blew my mind.

joined2

The two images above were both rendered in nearly 18 minutes on a 12 core i7 CPU. All materials and settings everywhere were exactly the same… sort of.

I’ve been playing with image stacking lately, mainly as a tool to render images and animations progressively, but when rendering some glass the other day, I realized that the only reason it renders so slow is because the noise and fireflies don’t change all that much, only more and more of it gets added and eventually averaged out. So if we change the noise pattern and render less samples a couple of times…

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