mental ray daylight problem

[jitendra]

no body is there to answer this...........?

[Lacrevette]

Hello !

Bring more points, like some screen shot of your scene, of setting etc.
Hard to answer there .

[jitendra]

Hi Lacrevette,
here r two screenshot of model. in closeup scene u can see the texture of stone wall is blurring in a specific direction. It's without PS. straight from max. and the second the complete one is corrected in PS. It's floor is not so sharp. tell me abt the lighting.

[jitendra]

nobody is there to help me or the question is not clear for u ?

[jitendra]

no answer from anywhere

[Ackee]

My first post here so it has to be validated first so... :)

Anyway, try to puy a gamma corrector between your texture and you maya shader (blinn etc.) Use a value around ~0.452 and you should be fine.

[jitendra]

Thanks, at least some body replied me. I am using max and will check if there is such option.
Thanks again.

[sepsis]

never used mental ray in max... but i had the same problem in maya... in maya you have to decrease the value under raytrace quality | multi pixel filtering...

hope this helps...

good luck! a.

[jitendra]

thanks buddy i will check that n let u know.

[jitendra]

hi, i tried that one. It improves the sharpness of image but there u can see another problem as the objects's edges r not smooth and having some black line on it. wht can be done now ?
The first image is with 3 x 3 filter size. and the second image is rendered with 1 x 1 filter size.

[Almir]

Are Using Max' Logarithmic Expsosure Controls?
Are you Using Physical Units?
Have you made any adjustments to the Mr Sun, Sky or Physical Sky?
Is your monitor Gamma Calibrated? is Max and\or Mat_editor Gamma Calibrated?
~sion

[sconlogue]

To avoid the aliasing issue you are having on the stairs for example you will need a higher min/max sampling rate. I never go below 1min 16max or 16min 16max if I have jags. Also you may need to bump the contrast up in your exposure control. I always find my daylight renders overexposed at default exposure settings. You can also try turning down the Skylight. This can wash things out as well.

[MinaRagaie]

Mental Ray defaults for anti-aliasing are set to low values for testing in most software...
sth that is very helpful in speeding render tests...
Max default scanline renderer (I really miss that renderer) is damn fast so it's defaults are set to almost production level settings...
I'd say your problem is mainly getting used to mental ray (no big deal) :)
as for the last 2 images u sent I think it's an anti-aliasing problem...
so here are some settings for production quality render...

min 0
max 2
Filter Gaussian
filter size 3*3
Threshold RGBA 0.5, 0.5, 0.5, 0.5

these values are no bible just my personal guidelines...
here are some guidelines for setting these to values that suites u best...

-for the final render you never wanna go to a min value less than 0... it will allow the renderer to skip whole pixels.
-if you're not getting the quality you need the max value is the LAST thing you wanna increase... try every other setting first... a max value above 2 can dramatically increase render time
-Contrast threshold can be anywhere between 0.1 and 0.04 (sometimes even 0.02) lower values increase both quality and render time and vice versa. always try this before increasing the max value above 2
-Box filter is good for quick tests
-Gaussian is production level (produces nice soft images)
-Mitchell is production level too, it produces sharper images with crisp details (my personal favorite, yet crisper details might require higher AA settings if you're rendering in passes)
-filter size values for each filter are...
Box 1 1
triangle 2 2
gauss 3 3
Mitchell 4 4
using a higher value than these will result in a blurred image

-one more thing ... I recall that the values "Min/Max" in max had different values than Maya and XSI
I think a value of 0 would be 1
and a value of 2 would be 1/16
you'll have to check the documentation for that

hope that helps

-Mina

Edit: noticed that I typed some wrong values here so I came back to correct them (higlighted in yellow), hope it's not too late :(

[jitendra]

Hi,
Firstly thank to all people who gave their precious time for me.


Almir
I am using Logarithmic Expsosure Controls with physical units. I don't made any adjustments in Mr Sun, Sky or Physical Sky. I have no idea abt calibration of gamma of max and my monitor ( don't shoot me for this... ) how it can be done if u can tell me it will be very helpful.

sconlogue
I will increase the min/ max sampeling in final render to avoid antialiasing. I found the skylight settings and renders quiite dull before i make correction in exposure control to make it more bright and contrasting.


MinaRagie
Thanks for this valuable detailed information. I will take care of all that in my next renders.

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