Here`s a few thoughts Tapani....
If your textures are only linked, try clicking the embed button.
Modifying Texture Settings – Basic
If your model components share a texture, changing the opacity on one will also effect the others.
Adding New Material with the Make Unique Feature
For each of your materials make sure the Alpha Threshold in the materials settings panel in Iclone is unchecked. When active it clamps the opacity.
I have a few “rogue”materials where if |I use full 100% opacity it causes erratic display problems but they seem to work perfectly well up to 97%. I have no explanation why.
When working in real time monitoring Iclone may drop frames to “keep up”, but at the expense of on screen fluidity. If you have not already tried it, maybe a rendered exported video version of your scene will display the smoother opacity transitions you require?
Geoff.