VRayHairNextMtl - changing materials via timeline

[marcin_surmiak]

Hi, is it possible to change materials via timeline in the VrayHairNextMtl material? I make fabric renders created with VrayFur. I need to automate switching via timeline so that the color of the material in VrayHairNextMtl changes on each frame. On regular materials, I have various materials connected to Multi/Sub-Object and on a given model I "record" a change to a different fabric using the Material modifier, unfortunately it doesn't work on VrayHairNextMtl, or I'm doing something wrong.

https://drive.google.com/file/d/1_1L...usp=drive_link
In the video I show what switching materials is all about.

I would be grateful for any tips

[hermit.crab]

Inside the VRayFur, there's a "MapID" option, which works similarly to the Material modifier you are using in the video. Use it instead.

[marcin_surmiak]

Thanks for the help, but unfortunately this method doesn't work. I know why now, because I render on GPU and therefore it doesn't change materials using MapID.
It works with VRaySwitchMtl but only on regular VRayMtl, unfortunately not on VrayHairNextMtl.

Below is a recording of what it looks like:
https://drive.google.com/file/d/1v4g...ew?usp=sharing

Is there any other solution for this?

[hermit.crab]

Try using the 3ds Max native "Material Switcher" material - it should work as expected. Otherwise, I'll log both other issues for investigation.

EDIT: Logged as internal tracker id: VGPU-6758 and VGPU-6759.

[marcin_surmiak]

It would be great if improvements could be made The option with the native Material Switcher works, but there is no option to record in the timeline.

[hermit.crab]

Huh, you're right. It seems 3ds Max doesn't allow the ID parameter to be keyed. The only workaround I see is rendering the animation manually through a script, where on frame change, the Material Switcher ID also changes. Here is a sample script:

fn MaterialSwitchKey =
(
startFrame = 0
endFrame = 3
for i = startFrame to endFrame do
(
rendTimeType = 1
slidertime = i
for each in sceneMaterials where classof each == Material_Switcher do (
if startFrame == 0 then each.selection = (i + 1) else each.selection = i
)
max quick render
)
)
try(MaterialSwitchKey())catch()​

It syncs the Frame Number with the ID of all Material Switcher shaders in the scene. I can adapt it to work for selections if you prefer. Simply edit the startFrame and endFrame value and run.