Node material showing black

[f2b]

Hello, time to time i have some node materials previews showing black in material manager. How could i resolve this problem please?

[f2b]

in this scene i converted some “standard materials” to Node materials. There was 60 materials and scene weight was 1.5Mo. After conversion of 5 materials to node scene weight is now 70Mo and save time is about 2 min! If i delete all objects and materials in this scene and resave, scene weight is always 70Mo and also 2min save time. Weird

[sirio76]

@f2b

in this scene i converted some “standard materials” to Node materials. There was 60 materials and scene weight was 1.5Mo. After conversion of 5 materials to node scene weight is now 70Mo and save time is about 2 min! If i delete all objects and materials in this scene and resave, scene weight is always 70Mo and also 2min save time. Weird

The scene weight issue has already been reported in the past, don’t know if its already solved in the latest builds

[deyan.hadzhiev]

Hi @f2b , this really seems unexpected.

@f2b

in this scene i converted some “standard materials” to Node materials. There was 60 materials and scene weight was 1.5Mo. After conversion of 5 materials to node scene weight is now 70Mo and save time is about 2 min! If i delete all objects and materials in this scene and resave, scene weight is always 70Mo and also 2min save time. Weird

Can you share such a scene (with the materials that were converted)? What is the original source of the materials - are they created from ground-up or are they imported from somewhere? Also - in the standard materials - are you using any shaders which are not natively supported by V-Ray (and would need to be baked)?

Such increase in memory might be explained if you are using unsupported textures in the classic shaders, which would be baked (or are using the VRayC4DBake shader). While this baking occurs on-the-fly when the shaders are classic, it is not possible when converting to nodes, so such shaders are baked and saved as scene assets in the scene database.

[f2b]

Hi Deyan, thanks a lot for your answer.

Indeed, there was C4D Brick shader in the source material. And it seems that black previews are due to broken links to baked source assets. But those baked asset remains in C4D file. Any way to purge those baked assets?
I guess i should let source material as standard one if there is no equivalent vray procedural shader in node.

Initially i was interested to tranform my material to node in order to use “UV Place 2D” node to rotate 90° some bitmap…

Also, could you confirm please if in “standard material” is there the possibility to rotate bitmap?

[sirio76]

You can rotate textures by using UVW randomizer, just set both value at the same degree

[deyan.hadzhiev]

Hey @f2b , glad this sheds some light onto to the problem. Now to specifics:

Indeed, there was C4D Brick shader in the source material. And it seems that black previews are due to broken links to baked source assets. But those baked asset remains in C4D file. Any way to purge those baked assets?
I guess i should let source material as standard one if there is no equivalent vray procedural shader in node.

The scene database is listed in the Asset Browser, but I also can’t seem to find a way to purge it. We will look into that in more detail, and also it may be best to add an option during conversion to actually store the converted baked assets as files, instead of using the scene database.

Initially i was interested to tranform my material to node in order to use “UV Place 2D” node to rotate 90° some bitmap…
Also, could you confirm please if in “standard material” is there the possibility to rotate bitmap?​

Rotating by 90° (or -90°) is fairly easy - you should use the VRayUVWTransform shader. The inconvenience is that for the classic shaders, the transform parameters are not shown as their decomposition of scale, rotation and translation, but rather as their vector representation in the composited matrix with offset. So you need to actually type in the transformation for rotating the texture around Z (basically the definition here - Rz(Θ)). So from the definition, you just need to set 1 or -1 as values in the V1 and V2 parameters as follows (keep in mind to use 0.5 as pivot):

​

Rotating by an arbitrary angle is a bit more complex, because you have to write the corresponding value for the rotation there (e.g. for Transform.V1.x youwould need to write cos(Θ), where Θ is the angle in degrees, and the corresponding values in V1.y, V2.x and V2.y). We are aware this is not very user friendly and may consider some UI workaround, if Cinema 4D continues to not show decomposited transform parameter in its next versions (in the classic shaders).

[f2b]

Thansk sirio for your tips

@deyan.hadzhiev

The scene database is listed in the Asset Browser, but I also can’t seem to find a way to purge it. We will look into that in more detail, and also it may be best to add an option during conversion to actually store the converted baked assets as files, instead of using the scene database.

Exactly, embeded scene assets seems not very well optimized, c4d side. External baked file it much more easily manageable

Thank you for UVWTransform explanation, but it’s too much developer oriented :-P. i will prefer Sirio method

i would like to mention that VRay supports for maxon noise shader is very very helpful. But can i ask you if support for maxon Tile Shader, Brick Shader and Substance shader are in the to-do list?