White points in KE04

Hello,

What are these white points on the walls around the girl? they seem to come from reflexions.

I already see that in the past on very reflective surfaces (posted few months ago), but I didn't have the problem in the same image in KC23.

A bit after at 170 passes, more and more white points

Below is the rendering with KC23. No white points.

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Permalink Reply by Render Plus on May 16, 2011 at 7:48am

What material is being used on the back wall?

(Is it one you had in SketchUp and added reflection to, or is it one of our library materials)

See what Sharpness is set to for the material. When Sharpness is less than 1.00, we shoot "random" points out from the material to get the "fuzzy reflection". This can take a lot more passes to resolve. Increase sharpness to .90 or better, or plan to let it render for a lot more passes.

Are you using the Path Tracer engine, or the standard Packet Engine?

If you like, send the model to support@renderplus.com and we will take a look.

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Permalink Reply by Alain Bonnefoy on May 21, 2011 at 8:43am

Hi Al,

I didn't really have time to spend to the problem because I have a heavy load of work actually and I've installed back kc23 and the white points desappeared.

Is it a new feature in KE04?

It's a sketchup material where I added reflection using "plastic" default setting. I never tried to experiment "intensity" and "sharpness" independently.

I was using packet tracer.

I send you the model to support@renderplus.com.

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Permalink Reply by Render Plus on May 21, 2011 at 2:21pm

Send us the model, and we will take a look.

We may need to change the shininess setting for our default reflective materials.

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Permalink Reply by Render Plus on May 22, 2011 at 10:18pm

Thanks for sending the model.

I didn't get the same white dots you did, but I did get some white dots after rendering with the Path Tracer for 100 passes: (Back Wall Settings: Highlight Intensity 25, Sharpness 20) (See 2X blow up below)

(This image is blown up 2X to let us see the dots better)
This was with the default plastic material - highlight intensity 25, sharpness 20

I increased the sharpness to 40 to see if that helped, it made the dots a little smaller, but they are stil there:

(Not necessarily in the same place because they are random)

Then I sent back to the original settings (Highlight Intensity 25, Sharpness 20), but let it run for 350 passes.

The dots after 3500 passes have almost disappeared.

One tip here is that with the Path Tracer yu may have to allow for lots of passes. Often 1,000 passes to converge all the dots which the Path Tracer creates while rendering. So, in general, you you should plan to use it when you have time to let 1,000 passes complete overnight or over the weekend.

I am not sure why you were getting different results with the version from March. (I am using the newest version which will be releaesd later this week). If you decide to switch to a newer version later, lets try some more samples to see if we can get things to work. But, with both of the rendering engines, in order to fix rendering problems like these you will need to let the rendering cook for a longer time.

For the record, here is the same model rendered with the Packet tracer for 35 passes and the Highlight Intensity 25, Sharpness 20 Settings:

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Permalink Reply by Alain Bonnefoy on May 23, 2011 at 12:40am

Ok Al,

I will switch to latest version asap and check it again. I hope it's not solved by the simplified model, normally, everything I removed doesn't affect light and reflections in this area.

I let you know.

Regards,

Alain

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Permalink Reply by Render Plus on May 23, 2011 at 6:36am

Wait until we put out a new version this wek.

Then, if it still fails, save the .SKP model after you start have started the rendering and send it to us.

(BY saving it after the rendering starts, we are sure that we have the same settings)

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Permalink Reply by Alain Bonnefoy on May 23, 2011 at 10:18am

Ok, I'm waiting for the new version, no problem.

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Permalink Reply by Boothy on May 23, 2011 at 11:27am

Hi Alain \Al

The white dots look at bit like the dreaded `sparkle artifacts` - have you tried selecting the `no light source reflections` option on the main tab of materials editor?

Boothy

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Permalink Reply by Alain Bonnefoy on May 23, 2011 at 11:41am

No Boothy but actually what I want to verify is if these points really appear with the latest rendering engine because as I said I don't have this problem with KC23 but only with KE04 so, I think I'll check again with KE04, keeping the same settings and the with the one released soon.

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Permalink Reply by Alain Bonnefoy on May 29, 2011 at 2:16am

Hello,

I Tried to render a new scene with KE26 and saw some white points appear. I tried to render it with KC23 and see also some white points so, maybe the settings were not exactly the same between the two tests I made. But I'm sure I didn't change material settings so light conditions (sun intensity, sky, HDRi light) can explain this difference I think.

According to my tests, on the image above, I got the points after more than 100 passes. If I increase the sharpness to 0.9, I get the points at the 2nd pass.

Anyway I think it's a bit desappointing to get a good image at here 300 passes and having to wait few hundreds more passes to hope to see few white points to desappear.

Do these artefacts really give pertinent result in some scenes?

Could we use the feature as an option in the settings?

Regards,