Wich OSA Filter to use?

Hi guys!!

Well, I have this very detailed stone texture that I´m sing for some bricks, and the shot I´m doing is a close up of these bricks.

I´m rendering the image with OSA 16 in 720HD, and the thing is that the small details of the texture are some how flickering. So, I´ve tried with the different Filter types and sizes and for example, with Gaussian the problem is solved but I lose too much sharpness, with Tent the flicker is even more grainy and bigger. I think I´m going for Mitch with a filter size of 0.90 because it gives a balanced result…

The question is, What Filter do you use for animation?? Is there a standard filter (a recommended one) or you have to evaluate the scene and choose the filter upon the the results you want??

Now, I´m thinking that perhaps I should bake the materials onto the objects, as bitmaps may flicker less than procedural materials due to the interpolation filter that Blender applies to them and mipmapping…

Anyway, post your thoughts on this matter!!


please read this section of the user manual http://wiki.blender.org/index.php/Manual/Rendering. Page 3 is on OSA, there is a page on the different filters (you want cubic sounds like), and on baking which you also asked about. enjyo!

I’m these days finishing a video and I’m experiencing the same problems. If you find a solution I’d be grateful to know. (and if I find one, I would tell also).

Mitchell filter is usually the best one to choose as it is the most mathematically exact reconstruction filter for over sampled renders.

As for flickering materials, There are two recourses: 1) you may increase the oversampling level but that will increase render time and depending on how your material is constructed and the size of the finer details, you may still get some flickering. 2) bake the material. In the end, this is the most controlable way to get rid of material flickering and it renders faster too.

Thanks for your comments guys!

Well, the problem is almost solved, and I´m still using Mitchell 0.9, as it gives a balanced result between sharpness in detail and soft edges.

The material consisted in 6 procedural textures, 3 of them affected the Bump and Specular channels. These where the problematic textures.

So, after a few baking experiments trying to combine the textures in just one bitmap, I decided to bake each of the three textures separately. Then, I applied each bitmap to its corresponding texture channel, and with a little tweaking I achieved a very similar result to what the procedural textures did, and the flickering disappeared completely.

Thanks again guys!!