Glass shadow colour

[andy_butler_7]

Hi all,

I'm creating an interesting material for a building. It's called dichroic glass. It seems in the reference image i have of a manufactured window, the material has some very interesting properties.

1. It changes colour depending on the viewing angle, a bit like pearlescent paint. This is simple to do in VRay.
2. the shadows it produces are purple.

So my question is this. It is possible to make the shadow colour that a translucent object casts, a specific colour? By diffuse it changes colour to any on the spectrum but always casts a purple shadow.

I can fake it by having two objects. One for diffuse that doesn't cast shadows, and a second that isn't visible, but casts shadows and change their materials respectively.

but i consider myself a purist, and would like to achieve the results without too much "blagging"

thanks in advance.

[Vizioen]

Hi all,

I'm creating an interesting material for a building. It's called dichroic glass. It seems in the reference image i have of a manufactured window, the material has some very interesting properties.

1. It changes colour depending on the viewing angle, a bit like pearlescent paint. This is simple to do in VRay.
2. the shadows it produces are purple.

So my question is this. It is possible to make the shadow colour that a translucent object casts, a specific colour? By diffuse it changes colour to any on the spectrum but always casts a purple shadow.

I can fake it by having two objects. One for diffuse that doesn't cast shadows, and a second that isn't visible, but casts shadows and change their materials respectively.

but i consider myself a purist, and would like to achieve the results without too much "blagging"

thanks in advance.

Have you tried using the OverrideMtl? https://docs.chaosgroup.com/display/...RayOverrideMtl

[andy_butler_7]

Hi Vizioen,

Thanks for the reply. I have tried the VRayOverrideMtl. Unless I am doing something wrong it doesn't work. Attached is a crude setup that i have. The reflect and refraction slots work (Red and Green mtls accordingly) but the shadow mtl, which is purple, doesn't produce a purple shadow.

This render has my overridemtl on the big sphere. The floor just has a standard white material and the small sphere a glass. So you can see that the reflection and refraction are working but the shadows not.

[Vizioen]

Hi Vizioen,

Thanks for the reply. I have tried the VRayOverrideMtl. Unless I am doing something wrong it doesn't work. Attached is a crude setup that i have. The reflect and refraction slots work (Red and Green mtls accordingly) but the shadow mtl, which is purple, doesn't produce a purple shadow.

This render has my overridemtl on the big sphere. The floor just has a standard white material and the small sphere a glass. So you can see that the reflection and refraction are working but the shadows not.

[ATTACH=CONFIG]32813[/ATTACH]

I've just tested this and it works fine here. I used the fog color to create the colored shadows as it is easier to get the color you want.



edit: You said you put the override material on the big sphere, but in your first post you said the glass needs to cast the colored shadows? Then the overridematerial needs to be on the glass sphere, no?
edit2: I've attached the scene for you (2014)
Glass_Shadow.zip

[joconnell]

Two materials. I'm using fog colour in both cases to drive the tint of the glass. You have one material where you have a gradient with all your various glass colours as swatches. You set it to mapped mode and put a falloff into the map slot - this picks a different colour from your gradient depending on the angle. Put this into your fog map slot. You put this glass material into the base material of a vray override material. Next in your shadow material slow, make another vray material, make it fully refractive and put a purple colour into the fog colour swatch. Play with your fog multiplier to determine the density of the shadow.

[andy_butler_7]

Fog colour it is then!

Thanks to you both, very helpful.

[andy_butler_7]

edit: You said you put the override material on the big sphere, but in your first post you said the glass needs to cast the colored shadows? Then the overridematerial needs to be on the glass sphere, no?

Yes that is correct. I was just making the big sphere solid to test the shadows, which is probably why i didn't try the fog colour!

[andy_butler_7]

edit: You said you put the override material on the big sphere, but in your first post you said the glass needs to cast the colored shadows? Then the overridematerial needs to be on the glass sphere, no?

Yes that is correct. I was just making the big sphere solid to test the shadows, which is probably why i didn't try the fog colour!