VrayFalloff shader and C4D fallof shader not working or limitations

[akos_kiss]

I'm having a really hard time creating complex materials (mostly metallic paints and complex carpaint shaders) because of the limitation of the vray falloff shader and the limited c4d falloff shader integration.

The first issue is that the the documentation says that the falloff shader is supported on both cpu and gpu modes but in it is simply does't work. The gradient map shows up in the render but after changing the gradient space or orientation nothing happens.
I tried using the vrayc4dbake utility texture but it returned the same result.

Just like in 3ds max the c4d falloff map is really important for creating more complex materials.

The supplementing vrayfalloff texture node has really few setting but the thing I miss the most is the ability to change the falloff curve/gradient. Basically i have no control over the fine details that are needed for complex work.
This is an example for something i'm working towards. A video by Jonas Noell.

https://www.youtube.com/watch?v=3KQyXoDkcVM

If someone has any workarounds it would be highly appreciated.

On the other note, are there any plans to extend the feature set of the vray falloff texture? Why does the documentation state that the c4d falloff texture is supported if this is simply not the case?

[sirio76]

C4D Falloff is supported though some stuff still doesn’t work perfectly. Obviously baking is not an option since it’s a dynamic effect. Vray falloff will work and you can do a lot with that, but if you need more control you have to look inside the node material options, there are a couple Vray shaders that should offer what you need. Later I’ll post an example.

[sirio76]

Here is an example, you can use the falloff and tune the result using a remap node:

[akos_kiss]

Thank you for the example, this is what i was looking for. Unfortunately I Still miss the c4d falloff textures feature set.
I've gone ahead and tested this in r23 but it look like something is broken. If i load a curve preset with more than 2 points it works. But when i try to edit a curve with 2 point it breakes and doesn't update according to the shape of the curve. And this i when i noticed that it looks like the remapped values don't correspond to the curves shape only the point values and some random tangent amount. I attached two examples. Am I missing something again? The falloff was set to perpendicular/paralel)


One more thing that could be useful if the curves adjustment had the usual "show in separate window" feature so that you can zoom in and out and make the graph as big as you'd like.

[akos_kiss]

Anyone else ran into this issue?

[aleksandar.kasabov]

Hello akos_kiss,

I apologize for the delayed reply.

I've gone ahead and tested this in r23 but it look like something is broken. If i load a curve preset with more than 2 points it works. But when i try to edit a curve with 2 point it breakes and doesn't update according to the shape of the curve. And this i when i noticed that it looks like the remapped values don't correspond to the curves shape only the point values and some random tangent amount. I attached two examples. Am I missing something again? The falloff was set to perpendicular/paralel)

This seems like a bug and I have reported it to our developers for fixing (bug ID: VC4D-1234). The current workaround could be to have an additional point to form the desired curve. I will keep an eye on that and will let you know as soon as we have any updates.

One more thing that could be useful if the curves adjustment had the usual "show in separate window" feature so that you can zoom in and out and make the graph as big as you'd like.

Thank you for your feedback! I have made a request for that (ID: VC4D-1235). I will also let you know once we have more information on the matter.

Thank you.

[akos_kiss]

Hi!
Any update on this issue? Since this post i discovered that the ramp node also has the same limitations

[deyan.hadzhiev]

Hi akos_kiss, since 5.20.03 we added support for the native Fresnel shader, although I suggest using the latest version from the nightlies. We still don't have support for the ramp or spline guides, but the same result may be achieved with more knots.
We are planning to add similar setup for the node materials in future release.

[akos_kiss]

Hi deyan.hadzhiev!

The fresnel shader is great and and i really like the growing support for c4d-s native shaders! But sometimes i need a much finer control off the gradient positions, and it it would be great if the spline guides would work as intended. Because atm the c4d fresnel shader is a better solution. I brought up the ramp node because it has a similar issue with the spline guides. mainly that the point are translated correctly but the curvature of the spline is missing.

[akos_kiss]

Regarding an other post i discovered that the filter shader with the gradation curves point tangents are not translated to vray correclty. This looks like a more global issue.

[aleksandar.kasabov]

Hello akos_kiss,

I managed to reproduce the issue and I have reported it to our developers for fixing (bug ID: VC4D-1373).

The current workaround to this issue would be to add the filter shader inside a VRayC4DBake shader.

I will let you know once we have any updates on the matter. Thanks.

[akos_kiss]

Hello ,aleksandar.kasabov,

I tested the filter shader gradation curves with the vrayc4dbake shader and discovered the following:

1. If I used a noise inside the filter shader, the noise mapping changes with the bake shader added
   • shader tree (deepest to highest) noise -> filter shader -> vrayc4dbake shader
2. If i use a fresnel shader inside the filter shader and then use a bake shader, the fresnel shader camera directions get ignored and the mapping changes i.e.: the gradient is not "looking at" the camera but is aligned to the Y axis
   • shader tree (deepest to highest) fresnel -> filter shader -> vrayc4dbake shader

I'm a bit confused about, how to use the filter shader with the bake shader. Could you please show an example?

[aleksandar.kasabov]

Hello akos_kiss,

If I used a noise inside the filter shader, the noise mapping changes with the bake shader added

There is a known issue (bug ID: VC4D-869) where the noise is rendered differently. I will notify you once we have updates on that.

If i use a fresnel shader inside the filter shader and then use a bake shader, the fresnel shader camera directions get ignored and the mapping changes i.e.: the gradient is not "looking at" the camera but is aligned to the Y axis

This is expected as the Fresnel is a dynamic effect and once baked, it will use the UVW coordinates.

[akos_kiss]

Hello aleksandar.kasabov I was wondering if there is some news regarding the remap node and curve sampling and reacting to the tangents of the point? I've tested with the latest version but i think it's still ignoring the curves "shape" and just connecting the point with a linear gradient.

[aleksandar.kasabov]

Hello akos_kiss,

This issue has not yet been fixed. In the recent update, we added many new features and fixed many bugs. We will continue improving V-Ray by fixing bugs and implementing new features and I will let you know as soon as we have any updates on this matter. Thank you.