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goodvibrato
08-22-2009, 08:58 AM
Hey, I'm using mental ray and I'm trying to render an image that is 1920x1080. Unfortunately, the edges and highlights are very jagged. There is stair stepping going on all over the place. If I lower the res to 1024x768 it looks good. I'm sure there is a way to get it looking good in HD, but everything I've tried for the last several hours has not worked. I've tried upping the sampling to 4, lowering the anti-aliasing contrast to 0.01, turning on jitter, enabling contour rendering, and have experimented with several other settings in mental ray as well as the shaders themselves. If anyone could offer some help on how to get crisp high res images I would greatly appreciate it. Thanks.

cbamber85
08-22-2009, 09:12 AM
Widen your anti-aliasing filter. And maybe change it to a 'dumber' algorithm - like box.

klingspor
08-22-2009, 05:01 PM
Is this for stills or animation?

For animation you should probably avoid too crisp images because it doesn't look that great on a TV screen. A box filter is fine in my experience, even if it looks slightly blurry on the monitor.
Renders much faster to boot!

goodvibrato
08-22-2009, 05:58 PM
Widening the filter and using box definitely smooths out the stair stepping, however, I think it makes the image too blurry. I was hoping for a very crisp render. This is for a still shot.

jeremybirn
08-22-2009, 08:36 PM
Mitchell and Lanczos both do better at making a still image look crisp than Box does.

But if you have filtering and sampling settings that look good at 1024, those same settings usually look pretty good at 1920 as well. Are you sure you're not looking at a re-sized image or having another problem, like a low-res shadow map or a low-res texture map?

-jeremy

goodvibrato
08-22-2009, 08:51 PM
Guys, I feel totally ridiculous. The render viewport was not on 1:1. It was zoomed in slightly. But, hey, thanks for the tips. Now I know what those filters do and that box would suffice for an animation. Thanks for your help.

goodvibrato
08-22-2009, 09:13 PM
Mitchell and Lanczos both do better at making a still image look crisp than Box does.

But if you have filtering and sampling settings that look good at 1024, those same settings usually look pretty good at 1920 as well. Are you sure you're not looking at a re-sized image or having another problem, like a low-res shadow map or a low-res texture map?

-jeremy

Yeah, another thing that helped was upping the res of my hdr file. I was using a 300x150 hdr file wrapped around a dome to light my scene. When I made my own 1920x1080 hdr file that took care of a lot of the stair stepping as well. I doubt it would need to be the same res as my image, but that is just what I used and it works a lot better.

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08-22-2009, 09:13 PM
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