"Create Fire Lights" Button places grid lights on active layer... hidden or not - 3ds max 2022

[Bowen Studios]

Hello,

I could not find another thread on this topic, so forgive me if this has been addressed somewhere else.

The "Create Fire Lights" checkbox in a SmokeFireSim's volumetric options rollout - when checked - will place the grid's light objects on the active layer, regardless of which layer the grid is on, and regardless of whether the active layer is hidden or not. Additionally, those lights are not selectable objects, so they do not show up in the layer manager or scene manager. Since the lights are handled by Phoenix at render time, I assume.

This seems like a bug/issue to me because in almost every other circumstance of creating an object in Max, if your active layer is hidden when you try to create something, you'll get the "cannot create object on hidden layer" error.

It also presents a possible "wild goose chase" when and if you do create those lights on a hidden layer, then go to render, and the fire simulator is not lighting up the scene, as expected. It is impossible to find the fire lights because they aren't actually objects/helpers.

Does this make sense? Can someone else confirm?

If it is indeed a recognized behavior of the plugin, is it possible for a future update to include a safeguard to prevent the user from accidentally creating fire lights on a hidden layer? Thanks!

[Svetlin.Nikolov]

Hey,

If you are using V-Ray, there should be just one light created, otherwise there would be a bunch of them. In either case, these light should be created only for the render and then should get automatically deleted. They are not supposed to be edited manually - all their settings should come from the options under the Create Fire Lights section.

So sounds to me like you are trying to do something specific. Can you tell us more about what you are after in the first place?

Cheers!

[Bowen Studios]

Thanks for your response!

I took a quick screen recording to show you what I am talking about: https://youtu.be/sHYHZCELQN4

In the video, I set up a very simple fire simulator using the "burning fire" preset on a sphere in a room. The only default value I changed before the video starts is the "light power on scene" - from 1 to 10.

The first render shows the default behavior of the simulator. The fire shows up and illuminates the scene.

Then I turned off the "create fire lights" option, and the fire itself renders, but it doesn't illuminate the scene.

Third: I changed my active layer to an empty layer (visible and renderable layer), then checked the "create fire lights" box, and the fire illuminates the room.

Fourth: I hide the active layer, render everything the same, and the lights no longer illuminate the scene.

Fifth: I un-hide that layer, and everything renders as expected.

Do you see the issue here? The fire lights are created on the active layer, but no actual objects, dummies, or helpers are visible in the layer manager. There is no indication that the fire lights and their creation are tied to the active layer.

Let me know if that makes sense! Thanks again.

[Svetlin.Nikolov]

Ahhh, thanks for the video, I see now - so the lights get disabled by appearing in a hidden layer. Will try to fix it asap and will ping you again.

Cheers!

[Svetlin.Nikolov]

Hmmm, using Max 2022, latest Phoenix and V-Ray, I can't reproduce it.

However, in your video I see something: When you turn off the fire lights, V-Ray's light cache is visible on the bottom of the room. The lights are not created, but the GI does illuminate the room a little anyway.

However, in step Four, when you hide the active layer, V-Ray's light cache does not show any illumination on the ground - it is completely black. Are you sure that the "100 2 furniture" layer you hide does not contain the room geometry by accident?

[Bowen Studios]

Hmmm, using Max 2022, latest Phoenix and V-Ray, I can't reproduce it.

However, in your video I see something: When you turn off the fire lights, V-Ray's light cache is visible on the bottom of the room. The lights are not created, but the GI does illuminate the room a little anyway.

However, in step Four, when you hide the active layer, V-Ray's light cache does not show any illumination on the ground - it is completely black. Are you sure that the "100 2 furniture" layer you hide does not contain the room geometry by accident?

That is interesting that you can't reproduce the issue. We are also using Max 2022.2, Phoenix 4.41.0, and VRay 5.2.1

And yes, the layer I'm showing in step 4 is completely empty. The little white triangle next to any layer in the layer manager indicates whether the layer has any objects on it. As you can see, the active layer in the video does not have that white arrow before or after I click the "create fire lights" checkbox. However, it is clear to me that something is being created on that layer when I check that box. Or rather, the active layer is taken into account when the fire lights are created "behind the scenes".

Also, if the room geometry had been on that layer, it would have disappeared from the viewport when I hid the layer (the grey shaded geometry in the viewport is the wall geometry).

Can we dive a little deeper here? Let me know if there are any VRay render settings that would be relevant. I'm using BF/LC, "render hidden lights" is unchecked... I'm sure there are tons of things that could affect this.

Thanks!

[Svetlin.Nikolov]

Since it didn't happen in my simple setup, there must be something more specific happening in your scene. Would it be possible to send it over (or a simplified version) with the exact steps that make it happen?

This is something we definitely gotta fix.

Thank you!

[Bowen Studios]

Since it didn't happen in my simple setup, there must be something more specific happening in your scene. Would it be possible to send it over (or a simplified version) with the exact steps that make it happen?

This is something we definitely gotta fix.

Thank you!

Sure thing! What is the best way to get the file to you?

Also, I did do one more little test... if I check the "Hidden Lights" box (Vray tab > global switches), the fire lights DO render when the active layer is hidden. So, at least on our end, that "create fire lights" check box is creating lights on the active layer, which then become hidden when that layer goes invisible. Anyway, hope that makes sense.

[georgi.zhekov]

Hey,

If the scene is simple as in the video - you can zip it and add the archive as an attachment to the post. If it is a bit larger you can use either Dropbox, Gdrive or something similar.
If the scene is confidential - you can send it over vie out support form here - https://support.chaos.com/hc/en-us/requests/new

Thanks!

[Bowen Studios]

Great, I've attached it here. I didn't include the simulation frames, hope that's ok! Obviously the simulation itself isn't what's important here, so I guess you can just simulate a few frames of that grid to get enough data to test with. Thanks!

phoenix testing A01.zip

[georgi.zhekov]

Thanks a lot for the scene and for the help, reproduced it. Will log it in our bug-tracking system and will update the forum thread when we have something.

Cheers!

[Bowen Studios]

Great, thanks!