White Spots Beside/Inside Glass Material

[Stevoid]

I am having issues with a "Glass" material in keyshot. I am trying to make a thick, clear acrylic-like material.

The issue is that after I render white dots appear around the acrylic objects.

The object is resting on top of a white mat. This object is a white paper info-card pinned between two layers of thick acrylic. There are also layers of thick acrylic on all sides of the object. You can see from the attached image that white dots end up on the white mat around the acrylic, as well as on the info card edges.

- Settings -

Material for Acrylic is "Glass"
- set to a refraction index of 1.2
- Two-Sided
- Color: White

Material for Mat and Card
- "Plastic" basic material
- Gloss: 56
- Specular: Mid Gray
- Basic Texture images applied

Environment
- Based on Overhead Panel Soft Spot Studio

Lighting
- Ray Bounces: 6
- Indirect Bounces: 1
- Shadow Quality: 1.4
- Self Shadows: Check
- Global Illumination: Check
- Ground Illumination: Check
- Caustics: No
- Interior Mode: No

Render Quality:
- Advanced Control
- Samples: 24
- Ray Bounces: 6
- Anti Aliasing: 1
- Shadow: 1.4
- Global Illumination: 1
- Pixel Blur: 1.5
- Sharp Shadows: Check
- Sharper Texture Filtering: No
- Global Illumination Cache: Check

- Software -

Windows 10
Keyshot 6.2.105
Autodesk 3ds Max Design 2015 17.0 SP01 Commercial

[guest84672]

Either turn off "global illumination cache", or render it out using "max. samples".

[Will Gibbons]

I'll look at your scene if I have time to later.

From what I've read, I've got a few suggestions:

1. Refraction index should be set to 1.5(ish) for that material.
2. I'd change the color to something a bit less than pure white. Maybe 98% white.
3. Change Ray bounces to 10. Not 100% necessary, but will likely help.
4. Ground Illumination may be causing your unwanted white areas.
5. I'd suggest using maximum samples (instead of Advanced) and set it to 300 or so and see how it looks.

I'm pretty sure the issue is your low sample setting of 24. Also, some materials allow you to change the actual material samples, which will help with how they resolve. You can try bumping them up to a value of 16 or so. Material samples (if available) are found under the Roughness setting. Click the triangle to expand.

Let me know if that helps.

[guest84672]

Here is the image I rendered. I unchecked "GI cache".

[Stevoid]

Thanks thomasteger.

That seems to work. A bit of a shame that's the only way to fix it; that "GI Cache" sure does help speed up the rendering from what I've seen. It'll be good to utilize on any renders that zoom in real up close on any acrylic pieces.

Thanks again. Much appreciated.