1) i create a simple box for the ground ( vray material)
2) create a simple plane for the opacity ( vray material with map in the opacity slot)
3) create a box for the glass ( simple vray material with refraction on)
4) create a Vray light
I cannot see the shadows through the glass. Can someone help me?
It’s very strange…
Do you have the same problem?
The 3d cylinder shadow is visible. I tried also without opacity, putting the map in the refraction slot but i have the same problem.
And probably I’ve found the reason…at least the setting that cause this.
That kind of result is the same if you set the opacity mode both “normal” and “Stochastic”.
As you can see in my scene, it seems that there is something strange with that opacity modes.
They modify also the mesh shadow that overlapping the opacity one (the cilinder in the middle of the opacity plane).
So, for a reason I’ll leave the devs to explain, this occurs when the bitmap filtering is at default 1.0, so lowering that will fix it.
Well, it fixes it in that the shadow seen through the glass matches the shadow on the ground on the opposite side (very weird behaviour when at 1.0).
It seems it’s linked to using an area light.
Switch to a sun and there isn’t an issue with the filter at 1.0.
The image from @Karonte 's first post has no shadow at all behind the glass from the plane with opacity map.
This issue, as far as I can tell relates somehow to Verge 3D and it is not a V-Ray issue.
There are minor differences in the shadow with different settings of the opacity mode and bitmap filtering. From the docs:
Opacity mode – Controls how opacity is sampled. For more information, see the Opacity mode parameter example below. This parameter is not available when the renderer is set to GPU.
Normal – (Legacy) The opacity map is evaluated as normal: the surface lighting is computed and the ray is continued for the transparent effect. The opacity texture is filtered as normal. Clip– (Very fast) The opacity texture is not filtered and it is clipped to either fully opaque or fully transparent based on the mid-point value. Useful when there are many transparent surfaces one behind the other like leaves. Stochastic – (Optimal) The opacity texture is filtered and the surface is randomly shaded as either fully opaque or fully transparent for a correct average appearance.
Thanks to all guys. I will try your solutions. I cannot unistall VERGE because i use it for some works.
The very strange thing is that i try with Corona render and all seems to work even with Verge installed ( verge is a webgl exporter, not a renderer ).
Regards
Hi, I did a few more tests.
The shadow is definitely different with the different settings mentioned above.
Here is a comparison between VRayBitmap and Bitmap nodes for the opacity texture:
In some cases the shadow almost disappears. The workaround is to use clip mode for the material’s opacity instead of stochastic or reduce the bitmap’s blur. .
I will check if this behaviour could be improved or not.
