HDRs causing random surfaces to emit light?

[emengstrom]

Hi all-

I'm trying to do a simple studio lighting setup using some free studio HDRs I found, but I'm running into a strange glitch: even though I'm only using two textures, both of which I've set using standard Twilight presets, when I render the image, random surfaces will appear to be emitting light. It's not consistent across textures; that is, if I have two objects, both textured identically, one of the objects will randomly emit light, the other won't. Has anyone else run into a glitch like this? Is it a Twilight bug, a problem with the HDR, or something else? Any help is appreciated, as I've been totally unable to crack this problem. Thanks.

[Fletch]

Some HDR images are brighter than others. Also some flares can occur with lower rendering presets.
Try setting power of the HDR sky to be .1 instead of 1 (default)
Make sure if it's a probe, use that sky type, if it's a spherical HDR, use Spherical sky type.

If it's simple enough, please post scene here for further more practical assistance.

[emengstrom]

Thanks for the response.

As you'll see in the attached file, it's not a lens flare issue. Several surfaces are emitting light, even though they are not set as light emitters. Only two materials are used in the render. If I change the HDR, different faces will emit light, though none of the materials settings will change. Changing the sky type and/or the power doesn't fix the problem either.

[Chris]

Fletch did not say a "lens flare". He means a light flare. You need to use a higher preset.

[Fletch]

Subject: inconsistant renders

Yoni, others...

If you have a scene where these light flares are showing up... the "sparkles"

Please open it and try rendering with these settings. Unzip and copy the render settings below into your "Custom" render settings folder: "...Plugins\Twilight\RenderSettings\Express\3) Custom "

On this scene provided by Yoni, there are no light flares in my tests, and render times increase by some factor(only is it a dramatic increase for High+).

Please start with trying the Low+Flarefix setting and then try the Medium, then the High!

get zip file download here)

[emengstrom]

Awesome, thanks.

If it wasn't obvious from my original question, I'm not exactly an experienced Twilight user. That being said, I'm not seeing a custom folder (1, 2, and 4 are there), nor can I seem to figure out how to create one. How do I go about doing that?

[Chris]

There should be a listing under your render presets at Presets -> Express -> 3) Custom. That corresponds to the folder in your SketchUp plugins folder, at Plugins\Twilight\RenderSettings\Express\3) Custom. Presets you copy there will show up under the Express -> 3) Custom listing.

[emengstrom]

Thanks, I fixed it. The "Express" presets I had did not include a 3) Custom, only 1) Easy, 2) Advanced, and 4) Animation, and for whatever reason, it wasn't letting me create a 3) Custom folder. But, after two restarts, it's working.

[Chris]

Huh, interesting. Thanks for letting us know. We may need to fix something in our installers as there should be a custom folder by default.

[darthekai]

sorry, ressurecting a dead thread again, but I am pretty sure I need flarefix render settings. I'm getting random point light source spawns during my animation no matter what settings I use. I am however "not authorized" to download the zip file. Would it be possible to paste it in a code segment here? I would greatly appreciate it.

Alternatively, can you just give me a hint? ive discovered it has something do with Irradiance Estimators/Diffuse Interreflection, as when i turn the whole segment off, the problem disappears.
am I on the right track at least?