Quick Preview and Volumetric Lights

[RoyBU]

I have been working on a scene with volumetric lights and wonder if I have discovered a small bug. Try the following:

 

Open a new project, default choreography. Change the view/render mode to shaded. Turn off the KeyLight and FillLight. Position the Rim light so that the entire light and the beginning of its cone appear in the camera frame (something like x -125, y 180, z -30). Change the cone angle to something like 30 degrees. Reduce the falloff to around 600 cm. Change the camera background to black (so the effect is easier to see). (You can also place an object in the scene to confirm that shadows are in fact appearing, but it isn't necessary.)

 

At this point, if you do a shift-Q for quick preview you should see the circle of light on the ground. Now turn on volumetric for this light. Quick preview should now be showing the cone of light as it passes through the air, but on my system (v.12t) it does not - I still see only the circle of light on the ground.

 

Now turn "cast shadows" off for this light. Magically, the volumetric cone appears. If you turn shadows back on, the cone disappears.

 

Now click on the "render animation preview" toolbar button and, with shadows ON, click in the chor to do a render. Once you get one frame done, it should correctly show both the shadows and the volumetric cone. Abort the render and now do a shift-Q quick render. Unlike before, it should now correctly show both the shadows and the volumetric cone. So it appears that after a render (with shadows on), the quick preview shows volumetrics properly when shadows are on.

 

But if you now save your project, then reload it and do a quick render, once again the volumetric cone will only appear if shadows are turned off. You have to do a render again before the volumetrics will behave properly.

 

I know my description is long, but it's actually very quick to carry out this experiment and I'd appreciate it if someone could confirm this behavior for me. It really drove me crazy when I was first starting to work with volumetric lighting and couldn't seem to get it to work.

 

Roy

[luckbat]

Thanks, but the forums isn't really the place for bug submissions. Hash Reports is.

 

I know you're just asking for confirmation, but it's not necessary. The bug submissions are semi-public, so they can be confirmed by other users after you report the issue.

[RoyBU]

OK, I'm glad to learn the proper procedure. I did try to go to the Reports area, but it required me to enter my nickname and password (even though I'm already logged in) and then claimed not to recognize me. Is a special account required for making reports?

[Rodney]

A:M Reports has a separate login/registration.

You can however use the same info that you do for the forum if that works for you.

[luckbat]

He means, you can create an account on A:M Reports and give yourself the same username as you use on the forums. You still have to create an account, though.