Gamma problem

[yourfather]

Hi all,

 

My bitmap woo texture looks great in the 3ds max material editor. But once I render it looks light. Much lighter I think it's gamma. Does anyone have any suggestions on how to get the wood texture to match closer to the material editor?

 

Thanks,

RS

[yourfather]

A little more info about my setup:

 

1. On digital tutors the instructor said to change the gamma preferences to 1.0

2. Save the renders as HDR files

 

His reason for this workflow was to take advantage of HDR dynamic range. He said never use 2.2 gamma when saving to the HDR format in 3ds max.

 

But maybe I should just save my files as tiffs with a 2.2 gama.

 

I think that would keep my textures and final render images more compatible?

 

Thanks again,

 

RS

[Guest calumreid]

Are you using Vray? What are your colour mapping settings?

[yourfather]

Hi Calum.

 

I'm using mental ray.

 

My color mapping settings? I never heard of that in mental ray. Sounds like it could be the problem.

[Guest calumreid]

Ah right, yeah sorry but im not that fluent in mental ray...first thing that comes to mind though is your exposure controls in environment and effects (press the 8 key)...seeing as you are going for linear workflow then i would assume that Linear exposure control (find it in the drop down menu) is what you need...maybe? haha im really not sure, just guessing! And yeah we work in 2.2 and save out to .tiffs

[Guest calumreid]

Or actually its probably "mr Photographic exposure control" you should select...have a play around and with them all and see what you get

[yourfather]

Yeah everything is pretty much standard in the exposure control. I'm using mental rays setting for daylight in door scene the exposure value is set to 10 and the contrast settings are 0 for highlight .7 for mid tones and 0 for shadows.

[Matt McDonald]

If your input gamma and output gamma are set at 1.0, your display at 2.2 and you are outputting to a 32bit file format (HDR, EXR) you need to apply a gamma gainer to your bitmaps and diffuse colors.

[yourfather]

Wow, ok so

 

1. Any bitmap even my bump and reflection map bit maps?

2. Any diffuse color, even procedural colors (even when I'm not using a bitmap for diffuse)

3. I should do this even though the bit maps look fine in the material editor?

4. What gamma should I set the gamma gainer to?

 

I think if I do this the bit maps will appear "darker" in darker in the editor correct?

[Matt McDonald]

Follow the link below, it describes a couple of different gamma setups for MR and I believe answers all of your questions.

 

https://area.autodesk.com/userdata/forum/1/14844_6fy3LuP7K8VVEoXAeDoY.pdf

[yourfather]

Thanks Matt.

 

Can you please enlighten me on a current issue?

 

1. I am saving some Render Elements "mr A&D Diffuse Direct Illumination", mr A&D Diffuse Inderect Illumination" (and a few others)

2. When they save to disk and i open them, I just get extreme blacks and whites.

 

Here are screenshots

 

mr A&D Output Diffuse Direct Illumination

 

 

mr A&D Output Diffuse Inderect Illumination

 

 

mr A&D Output Reflections

 

 

Rendering

[Matt McDonald]

the render elements are not affected by exposure control so you have to do exposure in photshop or whatever program you intend to do compositing.

[yourfather]

Thank you.

 

Can you shed some light on these two points?

1. Do you know which render element gives you a plain diffuse without any lighting?

2. There seems to be no data in the Indirect Illumination element. My geometry is completely white.

[Matt McDonald]

render elements really aren't my thing but I think you want the output: diffuse direct and output: diffuse indirect. In general, the elements labeled output are the sum of the level and raw passes.

[yourfather]

Thank you Matt.

 

You helped me out. I woke up to find my overnight render turned out not as expected. So before leaving to work i had to figure things out. And with your help, i was able to do so. I don't have a complete understanding of what went wrong but you got me out of a JAM. I thank you for that.

 

My next step in 3Ds Max is to learn:

1. Why and when to change the gamma

2. Why and when to use HDR images during saving rendered files

3. Why and when to use render elements.

 

Thank you again. Have a great day.

[blank...]

If anyone ever gets MR elements to behave i would like to know how you did it. If interested, you can read about my struggle with them (with no solution) here:

http://forum.nvidia-arc.com/showthread.php?12246-What-is-the-proper-workflow-for-A-amp-D-render-elements

[Nic H]

switch to vray imo

mental ray is redundant

[blank...]

switch to vray imo

mental ray is redundant

 

To each his own. I've tried vray, but it didn't agree with me. For me mental ray is more, what's the word i'm looking for, logical. And it renders faster.

[Matt McDonald]

If anyone ever gets MR elements to behave i would like to know how you did it. If interested, you can read about my struggle with them (with no solution) here:

http://forum.nvidia-arc.com/showthread.php?12246-What-is-the-proper-workflow-for-A-amp-D-render-elements

 

do you have filtering turned on in your elements? I think that might have something to do with your edges issue.

[blank...]

do you have filtering turned on in your elements?

 

Yes, they are on by default.