SP3 Issues - F-Number and Reflections

[jujubee]

Vlado - I'm noticing two problems in SP3. The second problem below may be related to the first one above:

1. I use baked-in LWF, IR and LC. I noticed that now I have to lower my f-number to a really low value in order to see a scene. Before, a value of 5.5-8 would work fine. Now, I have to set them at around 1-1.5 in order to achieve similar results.

2. I have a chrome material. It's black diffuse, grey reflection, reflection glossiness set to .85, and ward. It used to render fine, but now I'm getting black areas on objects with this material. It seems like not enough light is hitting these spots.

[natty]

Hey jujubee,

have you tried leaving the F-Number @ 8.0, and lowering the shutter speed to 40? Also if you are creating a chrome mat why would you use .85 for glossy's? Chrome isn't that blurred, instead use Fresnel set to 10.0 and a reflection of 255.

[vlado]

Vlado - I'm noticing two problems in SP3. The second problem below may be related to the first one above:

1. I use baked-in LWF, IR and LC. I noticed that now I have to lower my f-number to a really low value in order to see a scene. Before, a value of 5.5-8 would work fine. Now, I have to set them at around 1-1.5 in order to achieve similar results.

2. I have a chrome material. It's black diffuse, grey reflection, reflection glossiness set to .85, and ward. It used to render fine, but now I'm getting black areas on objects with this material. It seems like not enough light is hitting these spots.

I don't think any of these has changed since sp2, but it would be helpful if you can get me a scene for this to vlado@chaosgroup.com

Best regards,
Vlado

[jujubee]

@Vlado - I'll send you the scene.

@Natty - I haven't tried that but will give it a shot. Also, as I said before this has worked fine before in the past. I tried downloading someone else's chrome material as well from the Vray Materials website - and also came up with the same problem.

I should also note that I had this same 'dark' problem with another interior scene which was only lit up by vraylights (no sun.)

[jujubee]

@natty - I just tried lowering the shutter speed to 40 and the scene was very dark - darker than above. I had to take it down to 10 in order to get similar results. 3 gave better results but the scene is still darker in the non-direct areas than I would like it to be.

Also, the chrome 'problem' with my material is still there.

Your chrome works better for this scene. I think it's because the reflection is set to 255.

I think with mine, the non-direct areas (secondaries?) are not being traced as much causing the diffuse to shade those areas black (black is my diffuse color on my chrome.) I 'think' this is somehow tied with the fact that I'm having to lower either my Shutter Speed or F-Stop values extremely low in order to get somewhat decent lighting.

It still doesn't explain why in the past I hadn't problems, but in two of my latest scenes I am encountering them.

[natty]

Hi

Can you archive your scene and I'll take a look, your door handles look like a smoothing problem, try resetting the smoothing groups. as for the lighting i would need to have a look, but im sure its just something you have over looked.

nathan@rendertime.co.uk

[natty]

Hi jujubee,

I took a look at the scene and it is the smoothing, take the smoothing off and it goes away, see below. For some reason Ward doesn't like it, Probably how the mat is supposed to react with that much blur with the glossy... Switch it over to Phong and it works perfectly fine with smoothing on.

Smoothing on


Smoothing off


N

[jujubee]

Thanks man for looking at that. Vlado wrote back saying nothing changed between the different service packs.

I just don't recall ever having to lower the f-number that low before.

[natty]

im also looking at that and will send you a scene back shortly. max 2010.

[vlado]

I actually got pretty much identical renders with sp2 and sp3 for this scene.

Best regards,
Vlado