View Full Version : Is there even a need for a ray trace transparency with perspective camera?

03-01-2007, 01:36 PM
Hi everyone,

Was wondering if anyone can explain to me the needs for a ray trace transparency setting with the Perspective Camera. Here are the examples:

1) Classic Camera, Ray Trace Transparency Off
2) Classic Camera, Ray Trace Transparency on
3) Perspective Camera, Ray Trace Transparency Off
4) Perspective Camera, Ray Trace Transparency on

As you can see Ray Trace Transparency makes a difference with the Classic Camera, but does not affect the Perspective Camera. So I'm wondering why we would ever need to turn on Ray Trace Transparency for the Perspective Camera. Is there something I'm missing? If there is no need to turn it on or off (no difference), why is the option there when I use the Perspective Camera? Thanks guys.

03-01-2007, 03:17 PM
With transparency off, on perspective camera the refractive index is set to 1.0, so the ray doesn't bend - if it's on, then it'll bend the ray (assuming you've not used 1.0).

At least that's what I think it does.

03-01-2007, 04:47 PM
I tried Perspective with transparency off and refraction on, it works fine. I still get the same result if transparency is on too. So I'm starting to think it doesn't do anything. Which in itself is fine, but it would haven't been better if they made option un-selectable that isn't relevant.

03-02-2007, 02:00 AM
probably it has only effect when a scene with volumetrics is rendered?

03-02-2007, 04:12 PM
My grammar was way off on that last post. Hi 3dworks, I thought the same thing too, but my test scene is using volumetric lighting and hypervoxels. The manual document problems with transparencies when used with volumetric effects, hence the need for ray trace transparency. Obvious this is referring to classic camera, but is not stated.

All I ask is that users are somehow able to figure this out by either documentation or by disabling features in Lightwave that does not apply. Because running into these problems is frustrating, since I'm scratching my head wondering why it doesn't work and the help file is not helping.