Virtual material? What is it. (noob question)

[ciboulot]

Hello everyone,

Everything is in the title. What the heck are the virtual material? Noob question I know, but I didn't anything about it in the forum.
But maybe I am also a noob in searching the right result....

Thanks

[TBFX]

Hi Ciboulot,

The virtual materials are, as far as I know, unique to the Maya plugin.
They are a really cool thing JimStar created for us so that we could vary the shaders that are applied to instances. So if you have a bunch of objects instanced, for every shader that may be applied to an instance you can create variant shaders and connect the virtual material out pin of the original shader to the virtual material in pin of as many variant shaders as you like and when rendering the instances will pick up the different shaders based off the rules you set up in the virtual materials options.
Note: it's important that the connections go from the base material to the virtual ones (this is a little counter intuitive)

The great thing is we can use it on anything that shares the same shader, not just instances.

The options in the virtual material tab are as follows:
Virtual material weight - allows you to weight materials so that some are used more than others.
Non-permanent object material - if checked will reassign materials randomly per frame.
Virtual material type - None, turns it off. Random, assigns shaders in random order from the list. Round-robin, assigns shaders by cycling through the list in order.
You set these attributes on the base shader.

Hope that makes sense.

T.

[ciboulot]

Many thanks to you TBFX.

Clear and precise description, thank you for taking the time for it.
This is exactly the kind of stuff I was lookinf for my particles. Thanks.

If I may, I have another question. I don't find how do we make the environement rotate now. I just installed the new version and, I am a bit lost...

Thanks and have a great day.
Cib

[TBFX]

If I may, I have another question. I don't find how do we make the environement rotate now. I just installed the new version and, I am a bit lost...

You need to connect a transform node to the file texture.

T.

[ciboulot]

Yep, that's exactly what I'm doing, and it doesn't work. It works only for the Z axis. I try all the octane transform nodes...
I got back to 1.20a. I have to finish my project for the end of the week. I don(t have time for this anyway. Looking out for the bug is clearly not on schedule.

On a side note, I have to render a animation with particles. I did instance my geo, IT works well in IPR, but I cannot scratch threw animation with the particles being updated. It tried all the options for the geo (movable, scatter, etc. and same in the render settings).

Is there any way to get the instanced geos movable ? Would be super handy.

Cib

[TBFX]

Yep, that's exactly what I'm doing, and it doesn't work. It works only for the Z axis. I try all the octane transform nodes...

Interesting, it works here, are you sure you are translating the texture and not rotating it. Unless you also add a spherical projection to the file node you need to translate the texture to "rotate" it around the env sphere.

On a side note, I have to render a animation with particles. I did instance my geo, IT works well in IPR, but I cannot scratch threw animation with the particles being updated. It tried all the options for the geo (movable, scatter, etc. and same in the render settings).

Is there any way to get the instanced geos movable ? Would be super handy.

The settings for this should be as follows:
On the base geometry that you are instancing set the geometry type to Movable proxy, and animation mode in the render settings should work on either Movable proxies or Full.
Have you cached the particle sim in Maya? you may not be able to scrub just because the simulation can't keep up.

T.