question

Jordan Nelson avatar image
Jordan Nelson asked ·

My light only blooms in the mirror. Is this normal?

Hello Arnold Answers.

I was doing a quick scene render test and for the first time I added mirrors, I noticed the light sources are only glowing there and not in the main scene itself.

For this scene, I'm only using two lights: one Arnold disc light and one mesh light. I've also have an emissive material applied with the indirect diffuse set to 0.

I once turned off the emission material and toggled "light shape visible" but the bloom still only shows up in the mirror.

Regarding the mirror material, I'm actually using the physically correct version by placing a glass object in front of a really shiny metal base.

Edit: Here is the the actual scene information. Again, I did turn off the emission material and turned on "light shape visible" but the bloom only shows up in the mirror.

10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Lee Griggs avatar image
Lee Griggs answered ·

I would use a disk light and add a small amount of Atmosphere Volume. You could use Affect Reflection to control how much you want to see in the mirror.

2 comments Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Yes this would work well as well.

1 Like 1 · ·

Oh, I like this idea. And since it's a bathroom, I can even justify it by saying someone just had a shower, hehe. I'll try it out and post back the results.

1 Like 1 · ·
Jordan Nelson avatar image
Jordan Nelson answered ·

@Lee Griggs

Thanks. I just used that technique to control the bloom on one of my lights without having to affect all of them.

I've also made a few more updates.

Samples: In an earlier post, I said to use 5 in the atmospheric fog volume. However, after closer inspection I raised it to 10. This was to help clean up some harsh artifacting and noise.

EXR format over JPEG: This one should be obvious but an EXR format is absolutely critical for bloom, since there is a wider bit depth. Going with JPEG limits this potential since there is more banding and compression instead of a nice soft gradient. The image I posted above, the left is a JPEG source and the right (final render) came from an EXR.

I've also said this was originally meant for an interior scene, but since there are now so many ways to control the strength of bloom in the Arnold settings, I think the atmospheric volume could be used in any scenario.

For example, I was just outside and having lens flare would be important for all the car and street lights you see at night.


volume2.png (419.4 KiB)
bloom.jpg (66.4 KiB)
2 comments Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Yes, definitely. Atmosphere volume is great fun to play around with. If you get the time, could you possibly upload a final image with sample settings used? Btw, have you tried using the Arnold denoiser with this interior?

0 Likes 0 · ·

I'm doing a re-render of a previous scene for my portfolio, so I'll definitely have a higher res version of this ready soon.

As for the denoiser, yes. The picture posted above with the before and after comparison, the after is from a denoised source that I saved out as an EXR format. It's just that I posted it at 240p to get it out faster, but a HD image with textures will be ready by the end of the week. I'll let you know when it's finished.

1 Like 1 · ·
Mads Drøschler avatar image
Mads Drøschler answered ·

If you want the lamps to glow, you kinda need to add a post bloom/glare effect.

There is a free framebuffer for 3ds max you can download and give a try.
http://www.monotoneminimal.com/vfb

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Jordan Nelson avatar image
Jordan Nelson answered ·

One last bump, but I promised that after I had built my new PC, I was going to do a re-render to show what the bloom effect looks like at higher settings.


Render time still came out roughly the same (10 ~ 14 hours per image) but I made several improvements to the final resolution, increased sample counts and more importantly, I am now able to have both exterior and interior lighting at the same time (something that was impossible on my old computer). So now light flows in from the sky as well light being generated from several lightbulbs inside.


I've included all the images on my portfolio website and I plan on doing 3 more finished projects with the new bloom shader so there's still a lot more mileage I have for this tool.

https://www.artstation.com/artwork/zAqRN6




Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Jordan Nelson avatar image
Jordan Nelson answered ·

Bumping this again, because I finally upgraded my PC and thus, I can properly demonstrate how the Bloom should look without compromised settings.


I've also made some optimizations after taking @Lee Griggs advice on the ray samples (8 was too high. 3 is good enough for the diffuse and specular. 8 rays should be kept for transmission though).



I'm also in the process of reconverting my old scenes and rendering them with higher sample counts, but in the mean time, I did get to experiment with a simple environment.


optimized.jpg (1.1 MiB)
3 comments Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

What's your new system build?

0 Likes 0 · ·
Jordan Nelson avatar image Jordan Nelson xebajac@zdfpost.net xebajac@zdfpost.net ·

CPU: AMD Ryzen 5 2600X 3.8GHz

GPU: Nvidia GTX 1660 6GB

RAM: 3000mhz DDDR4 32GB

MOBO: MSI Carbon B450 Wifi


Even with these specs, I still plan on doing one more upgrade because, even though my renders are 10x faster than before, this machine is actually a mid-range by 2019 standards. I also want to change the ram. My current Mobo only supports Dual channel instead of Quad, so I'm only gaining half the bandwidth right now.

0 Likes 0 · ·

setup is still cool tho, my CPU is about 9 years, trying to upgrade

0 Likes 0 · ·
Lee Griggs avatar image
Lee Griggs answered ·

Looking good. Some of the sample settings look quite high though:

  1. Does the room look much different with just 3 or 4 Diffuse Ray Depth (should reduce render time)?
  2. Why is Specular and Specular Ray Depth so high?
  3. I would increase Camera (AA) to 5 and see if you can reduce Specular etc.
  4. You should only need to increase Transmission if you have a lot of rough refractive glass in the scene. If not I would lower it the default 2.
  5. Again 6 SSS will add a lot to the render times. What is in the scene needs SSS? Bowls?

There are some tips here for reducing noise in a scene.

2 comments Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

1. I did experiments with 3,6 and 8 ray depth and found that the difference in render time wasn't actually much. Increasing the actual samples of the diffuse,spec,trans had a bigger impact.

2. Too low spec samples was causing noise on leathery surfaces as well as metals like the refrigerator. Originally, 3 spec samples was the sweet spot but I bumped it up for the final render just to be sure.

3. When I was using depth of field, 6 Cam AA was the target, but I still needed more samples to clean up metals and leather surfaces. With DOF disabled, I found I could lower it to 3 Cam.

1 Like 1 · ·
oldtest.png (810.6 KiB)

Part 2:

4. Do you mean ray depth? I actually have a lot of hidden transparent surfaces with a water cooler and the TV screen being tucked in the corner.

5. SSS is for the indoor plants ( Palm leaf, Ginger and Aloe Vera). I originally intended to have an outside garden but I decided to save it for future scenes and use the house plants as a test run.

From earlier tests, I found that 12+ samples was needed for a clean surface, but I reduced it to 6 SSS which helped cut render time in half.

When I rendered the scene again using daytime lighting vs incandescent, 6 SSS is too low vs 8 samples.

1 Like 1 · ·
oldtest2.png (368.8 KiB)
oldtest3.png (411.6 KiB)
Jordan Nelson avatar image
Jordan Nelson answered ·

@Lee Griggs

I made backups of all the 32-bit EXR so I can definitely adjust the exposure. I was inspired by images I saw of 4K Blu-rays (in particular, Batman heh) so I was trying to mimic that level of exposure, but I think in the future I'm going to raise the brightness, especially since this is suppose to be Archviz and not Cinema.

But here's the settings and increased exposure.

The CPU I'm using is ancient, so I'm still planning on re-rendering tomorrow as soon as I swap out my i7 860 for a Ryzen 2600x. In the past, I did actually have some clean renders but since my scenes have gotten more complex, I just figured a 10 year old CPU just can't keep up anymore.

This was one of my earlier WIP scenes and it even had depth of field, but as the requirements got bigger, my computer started to struggle with rendering that would take days.


Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Lee Griggs avatar image
Lee Griggs answered ·

Nice. What samples did you use? Have you tried clamping for the fireflies?

Is it supposed to be that dark? Are you rendering to 32-bit EXR so that you can adjust the gamma/exposure in post?

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Jordan Nelson avatar image
Jordan Nelson answered ·

Apologies for the long wait @Lee Griggs I'm actually in the process of upgrading my PC, so some things still aren't final.

However, I do now have some HD images of the bloom in effect, and I'm actually going to do a 4 part series where I'll continue to toy with these settings under different environments that I'll be posting to my portfolio.

https://www.artstation.com/artwork/zAqRN6

Here's the first two.

Depending on how fast my new CPU is, I might even try to go from 720p to full 1080p HD.

Edit: Increased the exposure. I originally wanted to do a cinematic/4K blu-ray thing but I guess for this type of art (Archviz) that is not the best idea.


Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Lee Griggs avatar image
Lee Griggs answered ·

Nice, you can also reduce the effect on a per-light basis using volume contribution.

Share
10 |600 characters needed characters left characters exceeded

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Write an Answer

Hint: Notify or tag a user in this post by typing @username.

Up to 5 attachments (including images) can be used with a maximum of 2.0 MiB each and 9.8 MiB total.

Welcome to the Arnold Answers community.

This is the place for Arnold renderer users everywhere to ask and answer rendering questions, and share knowledge about using Arnold, Arnold plugins, workflows and developing tools with Arnold.

If you are a new user to Arnold Answers, please first check out our FAQ and User Guide for more information.

When posting questions, please be sure to select the appropriate Space for your Arnold plugin and include the plugin version you are using.

Please include images, scene and log files whenever possible as this helps the community answer your questions.

Instructions for generating full verbosity log files are available for MtoA, MaxtoA, C4DtoA, HtoA, KtoA, and Kick.

If you are looking for Arnold Documentation and Support please visit the Arnold Support site.

To try Arnold please visit the Arnold Trial page.

Bottom No panel present for this section.