random materials

[vladimir.nedev]

I setup them like this, is it correct ?

[ATTACH=CONFIG]24307[/ATTACH][ATTACH=CONFIG]24308[/ATTACH]

I don't think it is. There should be a color blend with "baseColor (2)" as input color 1 and "baseColor" as input color 2.
Then this color blend node is "input color 2" of another color blend, whose "input color 1" is "darkSpots". And so on.

Greetings,
Vladimir Nedev

[vladimir.nedev]

I have added support for the "stepped" slope type of gradient control points.
This means you won't have to do the Schematic trick with the multiply and floor nodes.
This change will be in the 2015-05-21 nightly build, as well as in the 3.00.07 open beta build.

Greetings,
Vladimir Nedev

[vladimir.nedev]

I have added the "V-Ray Switch Material".

Here is an example :



Note that in this case all the switched materials share the same bump map as well as the same clear coat layer.
Also you need only one "Variation texture" with a linear gradient from 0 to 1. You can modify this gradient to increase/decrease the probability of choosing a particular material.
Also note that with the switch material you can switch between materials of different types (standard V-Ray material, SSS, Car Paint, light material, etc.), whereas
with the "Group Mask" effect you can blend only materials of the same type.

Compared to the other Schematic materials (blend and 2-sided) the switch material allows multiple connections to its material slots, since the order doesn't matter
(unless the user wants to modify the probability for choosing a material).

This change will be in the nightly build from 2015-05-22, as well as in the 3.00.07 open beta build.

Greetings,
Vladimir Nedev

[John_Do]

Great job, you're fast

Well, I have to wait the 3.00.07 to test this, but it seems really promising, and simple ! Could you explain the relation between the gradient key's and the probability of choosing one or another material ?

Thank you very much !

[uncle pritt]

What a wonderful super fast addition. I wonder how this could be used to create little color variation like cgsource's multitexture for 3ds max. My main aim is to variate every plank in a wooden floor with few diffuse textures.
Thank you for the effort.

[vladimir.nedev]

Great job, you're fast

Well, I have to wait the 3.00.07 to test this, but it seems really promising, and simple ! Could you explain the relation between the gradient key's and the probability of choosing one or another material ?

Thank you very much !

The input values are split into intervals based on the number of connected sub-materials. For example, if you have 3 materials, the first one will be shown for values of the
input texture in [0, 1/3), the second one for values in [1/3, 2/3) and the third one for values in [2/3, 1).
The Variation texture takes the random particle ID (which is a value between 0 and 1) generated by MODO and then pipes it though the gradient control. Which means that
you need to have a linear gradient to preserve the original value (like I've done in the original screen-shot).

Let's say you have 3 materials and you want the first one to show 80% of the time. In this case, you put a gradient control point at 0.8 with a value of 0.33 and make it linear.
This means that any input values between 0.0 and 0.8 will get remapped to values between 0.0 and 0.33 which correspond to the first material.
In the attached screen-shot, the red material shows on 80% of the particles, the green on 15% of the particles and the blue on 5% of the particles.
The third control point from left to right is at 0.95 with a value of 0.66.
I have switched the "Particle Generator" to generate sequential particle IDs in this case so you can clearly see how many times each material was selected.
I am attaching the .lxo scene and screen-shot.


changed_probabilities.zip

In V-Ray for Maya the switch material works a bit differently. Input values between 0 and 1 select the first material, between 1 and 2 the second and so on.
This means that every time you add or remove materials, you need to modify the input texture to account for it, which is inconvenient.
The good thing about it though is that the intervals for selecting a particular material don't change when adding/removing materials, which might be what you
want if you are modifying the probabilities with the gradient. So maybe I should make this an option.

Greetings,
Vladimir Nedev

[vladimir.nedev]

What a wonderful super fast addition. I wonder how this could be used to create little color variation like cgsource's multitexture for 3ds max. My main aim is to variate every plank in a wooden floor with few diffuse textures.
Thank you for the effort.

For this we will need to add a "V-Ray Switch Texture" that switches between textures and not materials, but something like that may or may not be coming natively to future versions of MODO.
Also 3ds Max's MultiTexture seems more close to MODO's Variation texture in Item or Part mode, which is something
I still need to implement and will take more time than the switch material since it is not implemented in the V-Ray core (at least not in the way MODO does it).

About those wood planks, are they in the same mesh layer ? If they are, are they connected or disconnected polygons ? I mean can you double
click on each plank and have MODO select only that plank.

Greetings,
Vladimir Nedev

[vladimir.nedev]

I've added support for the "Texture switch" node from MODO 901. The change will be in the nightly builds from 2015-06-09, as well as in the 3.00.07 open beta build.

The texture switch is very similar to the V-Ray switch material, but switches textures instead of materials, which can be useful depending on how you are
setting up your shading network. It also has an "interpolate" parameter that will tell it to blend between adjacent textures, which results in more variations of
the input textures.

Here is a screen-shot :


And a test scene. You will need the MODO content installed, as the scene uses image maps from there.
tex_switch_example.zip

Greetings,
Vladimir Nedev

[John_Do]

Great feature !

I don't test this node yet, there isn't "variation source" option like the Variation Texture, so what is the element choosen for the texture switch ?

Thank you

[vladimir.nedev]

Great feature !

I don't test this node yet, there isn't "variation source" option like the Variation Texture, so what is the element choosen for the texture switch ?

Thank you

You connect anything you like in the "Input value". Most likely it will be a "Variation texture". But it can be a gradient texture with input set to incidence and a linear gradient, in which case the chosen texture will change based on the incidence angle.
If nothing is connected, particle IDs will be used automatically. I probably need to make the V-Ray switch material work like that as well.

Greetings,
Vladimir Nedev

[uncle pritt]

Hi Vladimir,
any update on the variation texture without particles or replicator?
I have a series of elements inside a mesh item, some wooden boards, and I wish to change the color of each board without doing it manually, there are a lot of boards. It could be explained like a bunch of closed boxes inside a mesh item.

Any chance to make it possible? I tried with switch material, but it doesn't work, or I can't make it work.
Thank you.

[vladimir.nedev]

Hi Vladimir,
any update on the variation texture without particles or replicator?
I have a series of elements inside a mesh item, some wooden boards, and I wish to change the color of each board without doing it manually, there are a lot of boards. It could be explained like a bunch of closed boxes inside a mesh item.

Any chance to make it possible? I tried with switch material, but it doesn't work, or I can't make it work.
Thank you.

I will try to implement this as soon as possible, seems to be the most requested feature.

Greetings,
Vladimir Nedev

[uncle pritt]

I will try to implement this as soon as possible, seems to be the most requested feature.

Greetings,
Vladimir Nedev

Thank you very much. I have to replicate this effect very often. This technique is super useful to break the CG look romiving that uniformity in the textures.

[7enith]

Yepp, please include it, I miss that feature too!
Light Select and Extra Tex might be pretty usefool too.

all the best
c

[vladimir.nedev]

So adding a composite texture would be really great, with 10/12 slots

For tomorrow's nightly build ( the one from 2016.01.08 ), I've added a "V-Ray Layered" texture, it is similar to the composite texture from 3ds Max.
It has only 6 slots, because that's how many are supported by RT GPU and also how many fit in the UI.
You can always chain 2 layered textures to get 11 slots. Once you run out of slots just connect the output of the current layered texture to the first slot of a new layered texture.

Greetings,
Vladimir Nedev