Speckles in custom renderworks

[petensen]

After trawling through the posts in this forum and trying a few workarounds, I am still getting speckles in my custom renderworks renderings.

I am rendering a VP on a design layer.

CUSTOM RENDERWORKS SETTINGS

Texturing

- Use Textures: Y

- Use Transparency: Y

Geometry

- Curve Detail: Medium

- Use Nurbs: Y

Lighting

- Use Shadows: Y

- Ray Traced Shadows: Y

- Transparent Shadows: Y

- Sampling Quality: High

- Layer Lighting Options

- Ambient: On (35%)

- Color Temperature: Mixed (5500K)

- HDRI: None

Final Gather

- Not used

Rendering

- Use Anti-Aliasing: Y

- Use Ray Tracing: Y

- Max Refractions: 32

- Max Reflections: 3

- Auto-Adjust Exposure: Y

- Brightness: 100%

Tried switching off nurbs, and checked that there aren't two VPs superimposed.

Using process of elimination, I have concluded that the speckles are being caused by the shadows of a directional light I am using (heliodon). When I switch the light or the light's shadows off, the problem disappears.

I have a similar problem when I use an HDRI background with the image, although the speckles in this case are much more subtle.

Can anybody help?

SYSTEM SPECS

- VW 2008 SP3

- Leopard 10.5.2

- Hardware

- Apple Powerbook

- 2.5 GHz Intel Core 2 Duo

- 2 GB 667 MHz DDR2 SDRAM

[grant_PD]

black speckles?

[petensen]

yes

[Ray Libby]

Could you post an image?

[Dave Donley]

Hello petensen:

This usually is caused by overlapping geometry, which can happen if you have a layer's geometry linked in multiple times.

Are the speckly parts of a particular texture like glass?

[petensen]

Yes, the speckly parts are mostly glass. I suspected the 'comb' effect. Does this phenomenon manifest itself only when faces are exactly co-planar, or does it also happen when faces are merely very close together (eg, 10mm apart)?

The image is a VP, but I have checked that there aren't duplicate VPs and that the geometry isn't duplicated either.

I will try to post an image but I don't have my own website so I'll have to figure out a way to host it on my employers' website.

[Benson Shaw]

Hi, Peter - Add a link if you like but you can also add images and files to your posts with the forum File Manager. Access File Manager by clicking the Reply button - the square one at bottom of each post. That opens a new reply window with areas for Icons, your post message, and Options. In the Options area, click the blue text "File Manager". This opens a window for adding files from your computer or network to your post. Click Choose File and navigate to the file you want to display, click Add File, Click Done Adding Files. Then Submit your post. Now the image or VW file will be in your post. This works with new posts and the Edit button, too.

Good luck!

-B

[grant_PD]

seen these before. Mostly when there is transparency, backlit objects, transluscent objects. Only a guess, but I suspect it's the limitations of the rendering engine. Of late I'm less and less enthused by Renderworks as a final rendering engine. Compared to Cinema 4d, it's not even in the same ballpark. A good compromise, as it's all in one package, but not really a "renderer."

[petensen]

I have added an image of the speckles (see red boxes). The window frame on the left is a WinDoor 13 object. The window frame on the right is a solid addition. I tried converting it to 3D polygons but that made it worse.

I am rendering a viewport with a heliodon light on the layer. The speckles disappear when I switch the light off.

Any help would be greatly appreciated!