Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - pokoy

Pages: [1] 2 3 ... 102
[Max] General Discussion / Re: Wide panorama picture?
« on: 2020-09-16, 23:27:25 »
If you really need it I guess you could go with another 2d software that offers these kind of image transforms.

If you tried to stitch several images and it failed, I guess it could be a problem if you use a backdrop image and the software failed to reconstruct a valid distortion due to a lack of a parallax change. If your camera only rotates around it's nadir and all images have the same fov and size I couldn't think of a reason why it fails. Never tried it though.

I believe that the reason you are not seeing the photon issue is possibly due to rendering at fairly low resolutions. Try a high resolution render with a region select (of say one of the lower coils), so it finishes in a reasonable amount of time and see if you see the issue.

I'll post an image to show what I am getting, soon - trying a few more attempts to get to the bottom of it.

The scene seems to render fine here with v6.
I now see that you mention using region rendering - I think this is generally not supported and can cause unexpected results with caustics.

You should definitely let the devs know - best through a support request - that caustics failed in your scene.
I have just rendered my scene for 3 hours with caustics and it did work like expected - in v5, that is, and with HDR lighting, so that's a different setup - so make sure to provide the scene to the developers and see if they can figure out what went wrong. I could do the same in v6 tomorrow, just to test if v6 in general works differently.

So here's the updated zip containing Max files for 2020, 2018, 2016 and 2014 with Corona v5, plus a screenshot of the material setup (all colors black/white except for absorption and scattering).

The HDR used for lighting the example was this one:

The missing geometry is something I can't trace back anymore so I can't provide a source, unfortunately. There are tons of good CAD models suited perfectly for this over at

Hey! I mentioned in my first post that I removed some stuff for sharing. The geometry you are missing is from a model on GrabCAD, I can post a link tomorrow. Obviously, I can't redistribute the data, but you can download yourself, and there are many other well suited models over there.

The HDR used for lighting my test scene came from hdrihaven, these again are public domain but I decided to remove it nonetheless... will post a link, too.

Glad you found it useful!! It's really very sensitive to lighting but I think the general parameters are acceptable. Then again, lots are left to play with and I had a hard time deciding which exact settings to go with. But that's the beauty of the scattering feature.
The only thing that's odd is how much scattering differs with caustics with exactly the same settings. I'm not sure what's going on there.

Your machine sounds about 10 times faster than mine :D

I might not be able to post anything today anymore, I'm afraid it's going to be tomorrow... Sorry.

Somehow missed that OP uses C4D. In that case I'll post a screenshot with color values... and 2014/2016 versions of the max file.

One thing I forgot to point out is that in Corona, surface and shading normals render differently with any sort of sss/translucency/absorption, so that you'll have to keep your geometry quite highres to avoid seeing faceted 'artefacts'. It's not visible in my render above, it's too low res and too noisy, but it can become visible in a cleaner highres...

Sorry, not in the office right now, I'll post a 2016 scene later tonight. Or do you need 2014?

I had a go at this... my thoughts were:
- it's clearly transparent/refractive so you need to with the refraction route with absorption and scattering (vs fraction)
- there's some rayleigh scattering going on (at least that's what it look slike) where certain wavelengths within the media get scattered more, hence the yellow/blue coloring. For this, absorption color needs to be slightly yellow (if you want this to be more or less pronounced, increase or decrease saturation in absorption color to control this effect)
- the internal scattering is pretty visible so scattering color has to be bright (the brighter the longer it renders, unfortunately)

Attached is a scene for max 2017 and 2020, give it a try. There's also another material done with the fraction route (it can't do refraction but it turns out pretty milky, you can also mix refraction/fraction in one shader if you want).

Play with:
- glossiness
- absorption distance
- scattering color (this one controls the scattering within the material, also, if you want the material to have a tone instead of the yellow/blue absorption, use this one, set absorption color to have no saturation then)

I also did a 10 minutes render with caustics. While it obviously took longer and is still quite noisy, the material looked much better since internal reflection were much more realistic, particularly visible on the tubes.

I had to remove some of the objects and HDR used in my renders, but the scene includes some lighting and the rolls, sheet and tubes.

One thing - the material is really sensitive in terms of lighting so keep in mind that any test you do may change considerably with different lighting ;)

[Max] Feature Requests / Re: Multiple LUTS
« on: 2020-09-03, 16:29:38 »
I see how this can be a real problem for the UI and its logic but I have to say I support this, found myself a few times in the situation where multiple LUTs would have been great to have. Maybe not 5 of them, but 2 would be great.

Thanks for the reminder! I've set it to 8192 at some point but I really don't need it most of the time, and scenes do open slowly... back to 2048 :D

If I remember correctly, the new OSL color correct map has an option to color correct only certain hues, might be worth trying if you're on Max 2019+... not sure if it really does this, though.

Another thing, but it depends on how true to world the new sky model is, the sky is always darker in opposition to the sun. It's the same in your example, the sun is behind the camera, lit objects are brighter causing shorter exposure/closing the aperture and making the sky darker/richer in return.

One important aspect to remember is tone mapping and color processing. The blue will vary depending on camera manufacturer/model so the result of what your camera 'sees' is pretty much an arbitrary decision made by the manufacturer. It can't really look the way colors are because they are interpreted by the camera's hardware and software. Even if the 'spectral color' in the photo and the sky map were the same you would not get the same output from the renderer unless all the color math is identical. That's why tone mapping and LUTs are such a vital part of the color discussion.

However, I totally see why you want to do this... Yeah, keying out certain hues and being able to color correct them is important every now and then.

Many thanks, you guys rock!

The new sky feels quite pale to me. Will the turbidity allow for a richer blue? Im currently switching between a clear blue pg skies hdri and the corona sun/sky and the latter is much more washed out and creates a flatter image out of the box without additional tone mapping. Good idea to use the colour correct node, does that effect performance?

Turbidity will probably make it less blue since it adds atmosphere fog/humidity. How blue the sky appears depends a lot on the viewing angle and fov. Sky is mostly dull towards the horizon, and if you use a tele lens it might turn out as light blue in such situations.
You can use a color corrected version of the same sky map in the background override only if it helps, make sure to instance it so it uses the exact same map.

you missed my post Romullus <crying>

Maybe you can catch something in Task Manager > Performance > Open Resource Monitor ?
You can then go to the Disk tab and sort by current total read/write.
My bet would be Windows Defender / Security. Especially if you recently updated.

Looks like I also missed your pointer when reading through the responses. I hereby step down from the issue-solver-of-the-thread position and respectfully hand over the title to you :D

It's an interesting question however why this happens in the first place and out of a sudden... or maybe a recent Win update plays a role in this?

Pages: [1] 2 3 ... 102