Transparent shadows quality is too low

[Amerio.Stephane]

Hello,

The shadow map used for alpha-blend materials with "transparent shadow" enabled  appears *as if* it is much lower resolution than the one used for opaque meshes (I know it's not the case, but it looks like that):

Worse, if I change the "Shadow/Softness" of the LightWorld from the default value of 1, the shadow does not look right at all:

softness = 0 ->; softness = 2 ->  

Similarly, increasing the Shadow/Sharpness from the default 0 to 1 simply makes it disappear.

In my test scene, the alpha is 0.30 and the shadow resolution is 1024.

I am trying to render accuratly an helicopter rotor shadow (to give some context, the rotor must visually transition from stopped to 300rpm, and the shadow must give a realistic visual feedback).

Thanks for your help

 

 

 

[sebastianbah]

Hi,

I'm afraid it's an expected behavior for the transparent shadows. If you need detailed shadows for the transparent objects, it's better to increase shadow resolution.

Thanks!

[Amerio.Stephane]

Hi,

Surely it's not the "expected behavior" by your end-user, but I understand it works as intended with the currently implementation. 

Going forward, I probably won't bump the resolution up to 4096 just for the rotor shadow, so what would be the current valid approach? Don't know if it's already possible, but being able to tweak the opacity of the whole shadow buffer could help (having the rotor in one buffer with low opacity, and the rest of the scene in another one with full opacity) 

Thanks for your help.

[demostenes]

What about duplicating such surface, use it as shadow caster and use camera mask to not render it? It should be even performance more friendly.