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View Full Version : Please "Dirtmap" for XP 64!

treedee
10-07-2006, 03:27 AM
Just trying to spark some attention. I know everyone keeps saying to use mib_amb_occlusion, its just Dirtmap has much more control and way faster than the AO shader. Plus I'm trying not to move over to 32 bit OS. I'm pretty content with 64. Can anyone out there recompile this terrific shader? Cheers,
MasterZap
10-07-2006, 06:21 AM
There is no perceptible difference in speed between mib_amb_occlusion and dirtmap.

If you compare the sources they work in a very very similar way, nearly identical.

This "dirtmap is faster" is a misconception stemming from the fact that Dirtmap by default has a limited distance, and mib_amb_occluson by default has not.

Furthermore, Maya 8's AO shader has a much improved sampling pattern than the previous ones (more coherence).

/Z
treedee
10-07-2006, 05:06 PM
Thanks zap,

Well in order for me to acomplish what I can do with the dirtmap shader takes a bit longer and I get very different results. If I'm doing it correctly (maybe you can tell me) but I usually apply it to the ambient tab of my shader. Instantly I get decent results using the dirtmap shader, and suprisingly it seems to calculate faster. OK, so I bring my work home and try to replicate the exact scenario with the mib_amb_occlusion shader and as soon as I render it seems much darker, with much more grain and takes much longer to finish rendering the frame. So maybe in theory it may be identical, but as I see it in front of me seems to be a bit slower with very different results. I know you are a genius with this topic, so maybe I'm not doing it correctly as far as how I would setup the mib_amb_occlusion? Thank you for the insight.
treedee
10-07-2006, 05:40 PM
OK,

after further review Im noticing that it may have to do with my render settings. I do get quick results with the mib_amb_occlusion shader when my settings are low, I just have to adjust my samples so it doesnt take the hit at render time. still would be nice though.
Puppet|
10-07-2006, 06:58 PM
to MasterZap:

Does improved sampling pattern is shader code part or mental ray 3.5 core?
Does my shader will have improved sampling pattern after recompiled for mental ray 3.5? For example code like Dirtmap shader.
daddyo
10-09-2006, 10:46 PM
puppet= nash geroy 3d truda!
pixelmonk
10-10-2006, 03:31 PM
puppet= nash geroy 3d truda!

and this means what to the masses?
MasterZap
10-10-2006, 07:26 PM
to MasterZap:

Does improved sampling pattern is shader code part or mental ray 3.5 core?
Does my shader will have improved sampling pattern after recompiled for mental ray 3.5? For example code like Dirtmap shader.

What was changed in 3.5 is that instead of creating a simple 3d displacement of the ray direction based on a 3 dimensional mi_sample() call, I create a 2d mi_sample() and use mi_reflection_dir_diffuse_x() to create a stratified set of rays.

The "_x" variant of the reflection functions aren't new to 3.5 (they were new in 3.4), but I just didn't use them before.

/Z
MaNdRaK18
10-10-2006, 08:14 PM
and this means what to the masses?

"Our hero of 3D work" - in russian.
Sounds simillar in Serbian ;)
bazuka
10-11-2006, 07:45 AM
man not even close to serbian :)
pixelmonk
10-11-2006, 02:12 PM
ahh cool.. I thought I was missing out on something ;)
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