3ds max Lighting problem with Arch & Design material


#21

Low final gather quality? or photons GI possibly.

Could also be due to precision issues like if your box is far away from the center, so low FG or GI settings become troublesome. Or a combination of stuff. Maybe I’ll check it out.


#22

Floating point errors?
Are you working at a microscopic scale? This usually doesn’t work well in any 3d software (maybe a scientific visualization software can).
The number values past a certain place value just get rounded too ‘approximately’’ and the errors manifest in weird and wacky ways.

Better to work at a common real world scale and make things ‘look’ microscopic. If that is the root of the issue-this is the only way around it.


#23

I bet that its a problem of the - possibly quirky - Archviz shader he is using interacting poorly with a low photon count, bad final gather setting or similar.

I don’t see why you need to use a “special” archviz material in the first place. Normal shaders render archviz like walls and floors just fine.

If this is MentalRay, that’s not exactly an easy to use renderer. I used to use it back in XSI and spent hours tweaking render settings.

That’s why I recommended he take a peek at ProRender - its free and supposed to be easy to set up.


#24

This one should have really be posted in the Max section, not only because some mental ray settings will not be universal across all apps but also because only a few will know mental ray in Max well enough to say what could be the culprit here and help you out.

First of all, the result you’re after will be hard to get with mental ray, mostly because mental ray’s GI is based on photons and the effect you want will just be way more precise and look better with brute force GI or path tracing (or similar apporaches using caching). Depending on the object’s scale, photons may leak through the geometry, even with high photon counts. Another problem is that the light is very close to the surface which will produce photons with super high intensities, this poses a problem for photon maps in general. The Arch&Design material is certainly not the root of the problem here.

Depending on the Max version you use, switch to the ART renderer (introduced in Max 2017) as this one is a path tracer and will produce a photorealistic and physically correct result out of the box. If you’re on Max 2018, an alternative is to use Arnold as this is a brute force GI renderer and will be similarly accurate as a path tracer. Using the free ProRender will also be easier to set up and provide a way better result.
Whatever you do, do yourself a favor and don’t touch the integrated version of mental ray in Max if you want to keep things straight forward and clean. Its days are over and some of the advanced new tech in it was never exposed to the user. You may have more luck with the current version which is now developed by Nvidia but I don’t know enough about it to say anything positive or negative.


#25

I am not using Final Gather whatsoever and I believe I am using quite a high value of Photons for GI.

If you do check the file you should find everything centered.

Absolutely not working at ridiculous scales and is on the ground plane. Quickly checking the box, the measurements work at roughly 60cm x 60cm x 60cm. Surely that must be fine, right?

I’m using an Arch and Design material and rendering with Mental Ray. I’ve seen plentiful Mental Ray renders over the years (even before the rise of V-ray) and they all managed to put out wonderful results, especially in Architecture renders where the scene is quite complex, with this I’m trying to do a very simple scene and it’s both interacting incorrectly. I’m sure I’m missing something, once it’s figured out I can finally move on with life :slight_smile:

Veeery interesting and informative! I was not aware of this “Brute Force GI” technique, something I definitely need to look into!

If it helps, I am using 3ds max 2011 and rendering with Mental Ray. Now before anyone cusses me for using such version, I believe not everything has to be new in order to achieve the best results, I’m sure you can agree it is more than capable to do some of the simple stuff, and the other reason is because it was the final version that had “Reactor” physics engine, yes yes I know you can get MassFX and Rayfire etc etc. a great piece of tool built within 3ds max to do great simulations :slight_smile:


#26

The oldest Max version I have access to is 2012 and I just tried to set up the scene and yes, it produces all kinds of strange effects. If I remember correctly, Final Gather is a very important step in photon GI as it will refine the photon map, without it the GI will always look patchy and be too coarse.

It also might be that the Translucency in the Arch&Design shader is anything but accurate, I guess it’s a hack to get a SSS-ish look. You may want to switch to true SSS shaders when using mental ray, I’m sure you will be able to find a tutorial or two reaching back as far as 2011.

If you were on Max 2012 you could use iray… Not sure if it was available in 2011, if it is, consider using that instead. It’s a path tracer and will do a lot better in a case like this.

Also, consider posting a screenshot of your render settings and the material, and really move the thread to the Max subforum, way more likely to get some good advice.


#27

That’s very interesting, I would’ve always thought their Arch & Design materials were more technically superior (in terms of accuracy as well) although I still feel it is.
However your comment about the Translucency in the shader may still yield true but the thing is I am still getting this result of light effect on the box WITHOUT Translucency or Transparency enabled. Also I am sure I have posted before that I have tried other shaders and I do still get the same effect (driving me insane even more!) :frowning:

What part of the Render settings would you folks like to see? I can screenshot to your hearts content! :slight_smile:

Incase the link expired, again here is my project file for the scene!: https://ufile.io/fqu1p


#28

Actually by today’s standards you are using pretty old tech. A lot of folks are doing this faster and better than mr today and the industry has embraced them if you look around.
And you are using 2011 as well…


#29

First, why are you not using FG? I can open your scene, turn on FG and instantly/magically the box blocks the light appropriately. If you have been at this for weeks and haven’t tried FG, then you need to rethink your methodologies with mr and start flipping switches, turning knobs, twisting dials to figure out what everything does. Depending on your end goal with this project, you may not need photons which will greatly speed up rendering. If you need photons, then you need to learn how to tune the number of photos you use with FG settings to get better render times. It’s tricky, but possible, and as others have suggested, not the fastest end to the means, but certainly cheaper. If this is for an animation, you’re going to have a tricky time with flickering, but that’s a whole different animal.

Second, if you’re trying to cheat sss by using translucency on your box material, you need to actually add a little transparency, as well. Light will not pass through a surface that has zero transparency as your material is currently set. Again, you need to learn how to tune between transparency and translucency to get the effect you want. Finally, if you’re looking for a box with thickness on the sides as your file shows, you’ll need to use sss and cannot fake this without some clever geometry tricks; however, for a thin-walled box (no shell thickness) this cheat will work with a little transparency dialed in. Just make sure you’re set to “thin-walled” under advanced reflectivity options. Good luck


#32

Thank you for giving the solutions.