ProMaterials and .png files

[Russell L. Thomas]

Written by Jeff Patton Monday, 18 August 2008 14:44

In case you haven't noticed, there's some fairly extensive .mat collections for the ProMaterials available in 3ds Max 2009. I've noticed some of the .PNG texture maps used in these collections act "weird" in 3ds Max 2009 in terms of gamma. I'll show the issue & explain further below.
If you've enabled 3dsmax's gamma options (like using gamma 2.2 for system, input & output) then you'll probably see something like this when using some of the ProMaterials:

(click image to enlarge)


Note: This only affects the .PNG maps. Some of the ProMaterial libraries use .jpg's and they load as you'd expect.

I corrected the display issue by applying a double gamma curve (4.4) to the .PNG maps by using the gamma/gain utility shader.



I've gone through the hardwood .mat collection and modified the ProMaterials that use .PNG maps to adjust for my own use. I figured I'd post the .mat file for anyone else that has encountered this. Just a word of caution: Since I primarily do not use the 'real world scale' option I have reconfigured these to eliminate that.

I've also configured these materials to display in the viewport when applied, however in the viewport they will probably still appear washed out...but at least the maps are visible. I also reduced the blur value to make the textures nice and crisp looking.

(click image to enlarge)


So now when I use a ProMaterial from the hardwood collection that is configured with one of the .PNG files, I get the result I'm expecting:

(click image to enlarge)


(click image to enlarge)


(click image to enlarge)


You can download my reconfigured ProMaterial Hardwood collection here:
http://jeffpatton.net/blog-images/Promats_Hardwoods.rar

Note: Bitmaps aren't included as you should already have those with your 2009 installation.

A note from the Welcome to Mr Materials! front. A huge thank you goes out to those that have contributed so far! Although I have to say that I've been a bit surprised to see the lack of participation from the mental ray community.

We have grown to over 3000 members in a short amount of time, which is awesome (thanks for the support). However, uploading/sharing of materials has been very limited so far. Different story with downloads of course, but that's to be expected.

So I have to ask, what's the hold up? If there's something about the site that you don't like, or something that just doesn't work for you, let us know so we can make any needed adjustments. There's a forum here: Mental Ray - 3DAllusions - Visualizing Possiblities! where you can post comments, questions, etc..

Actual Blog Entry:
ProMaterials and .png files

[section1]

That is something I noticed myself even though I am very new to mental ray having just recently switched over from vray. I read one of your posts last week about gamma corrections within mental ray and I immediately adopted the work flow, after doing some test renders I noticed not only with promats but with A&D I had the materials appear darker than what they originally are and this also applied to jpegs.

You said you put in a gamma of 4.4 I left it at 2.2 but dropped the gain multiplier to 0.5, the results were identical to the original pic file. This to me is an annoyance that I find with mental ray but on the other hand the quality of output I am getting in my renders I am very pleased with.

Even though Vray is an outstanding, quick and simplistic renderer to use I found that mental ray once mastered tends to produce much more pleasing visual renders it is as for me anyway as if you are looking at the object with your naked eye and I cannot call that photographic but very natural, very beautiful.

[Rod]

going to have to play with MR soon.....

[neil]

Great news Russell. Thanks for sharing with us

[Russell L. Thomas]

I just posted Jeff's blog entries from our other site MrMaterials here in the forum as it is easier to have a discussion than the commenting system at that site. The gamma issues haven't really bothered me, I use LUT set up with 2.2 and 2.2 from Max 2008 and up since it has the photometric exposure and have no real problems, or nothing I didn't have in the past with just about any software. The other item as far as renderings go is to use the photometric settings to adjust brights, mid-range and shadow to get the punch you want and illiminate the washed out appearance you may be getting with default settings. I would read Jeff's Blog entrys at mrmaterials.com for specifics and examples. In addition the thumbnails there pop up to the large and full versions, here in the forums are just a simple copy.

I personally like mr rendering better than vray, but vray has better proxies and support community, or I should say a contributing community, people like Jeff and Master Zap are shining stars in the Max mr community in my opinion.

[JeffPatton]

FWIW, if you're using the following gamma settings:
Display = 2.2
Bitmap Input = 2.2
Bitmap Output = 2.2

Then if you load the .png files & use the "Use image's own gamma" setting on the bitmap loader then it should render correctly. If you're using different 3ds Max gamma settings or gamma is disabled then you'll need to use the gamma/gain utility shader to properly adjust.

In the past I've also tweaked the output/RGB values to tune bitmaps, but I stopped doing so after I heard Zap mention that it could possibly cause artifacts in my renders.

[section1]

hmm I found that if I use the use image's own gamma settings in the small preview windows the image appears to be washed out so I just input a a custom setting of 2.2 and it darkens the image which appears to look normal. This is regardless of whether or not I use the utility.

I'm just curious as to how you input a gamma of 2.2 in an image in Photoshop, because there is one file that I have that has a gamma of 2.2 already applied to the image and that's the only image I can use the "Use image own settings" without it appearing to be washed out.

Also is there a work around without the materials in the material editor window to not appear washed out. I find this to be frustrating when compositing and colour correcting the materials.

One last thing I would like to ask being new to mental ray and using the A&D design all the time as oppsed to the standard I haven't the faintest idea on where to slot the specular maps and ambient occ maps.

Right now I'm using the amb occ map in the additional colour map slot and the normal and spec map in the bump>normal bump> and in the normal bump slot is my normals map and in the additonal bump is the spec map. I also set the method to screen it just seems to bring out more detail to the image than leaving it set to the dafult tangent.

If you could advise me on what is the correct method of application it would be greatly appreciated, thanks in advance.

[Damabiah]

Always thought there was headaches about gamma only in mr for maya, seems it's not the case, hope everything will be working without gamma correct anywhere in the future (mr detecting the colorspace of the texture and doing everything on his own).

[section1]

Hmm no answer from anyone of well I'll keep searching the net for my answer

[Russell L. Thomas]

People are very busy and instructions have been given that work for the gamma work flow. Additionally if you just show up and post questions without participating in the forums and hope people jump through hoops to answer your questions, your wishes may not come true. If you download materials at MrMaterials and investigate the settings you will see where people put maps.

Not meant as negative response, just the "Reverse Psychology" tone to your last response isn't going to inspire further help, if you want to bump the thread so to speak, try posting a screen shot of your problems or ask more specific questions to bring people back to the thread, sometimes we mean to come back when we get a moment and life and responsibilites hijack our attention.