[TZORG]

Hi,

I use C4D, and often I have a texture under Transparency to use as a transmap. When I send the scene to MXST, the plugin prefers to put the transmap under transmittance.

It makes sense to me that you could put a map on transmittance, but it has never looked right to me, and I have to replace it with the clip map. I've just assumed it is a flawed approach. So I decided to do a comparison test to try to understand the problem. I made a big purple cube, UV mapped it, drew a random black/white transmap, and sent it through.

So, here are two pics, the first using the transmap under transmittance, and the second using it as a layer opacity mask (clip map wizard). I think from the second pic you can guess what a simple transmap I made; it doesn't have lots of small spots in it.

I don't understand why the first pic looks like that...?

Thanks for any thoughts.

[Bubbaloo]

With a map in the transmittance slot, the material will utilize attenuation and index of refraction in the "clear" parts. This is not true if the map is put in the layer opacity slot.

As for the dots, I don't know what's going on. Maybe interpolation is on? Or the map is not only 0 and 255, but has some "in between" pixels, while layer opacity works ok with grayscale images.

[TZORG]

hrm, ok. I checked and even if I ensure the pic is 2-color, when I save/load [as .jpg] it is 6-color. If I save as a 2-color .bmp it works as a transmittance map. Also, if I max out contrast and saturation for the image (within MXST), it seems to work as a transmittance map.

However, this isn't a great solution as sometimes a transmap deliberately uses shades of gray... I'll have to try it

Thanks.

Incidentally the attenuation and refraction come in as 5 meters and 1.0. Roughness 0, but I change that. I have tried jacking up the attenuation, and also turning interpolation on, but that wasn't effective.

[Bubbaloo]

Best solution: put the map in the layer opacity.

[TZORG]

Haha. What I'm already doing.