Generating an Inverse displacement to work as shell

[Mousa_SA]

Hi,

The following could be a complex feature but it would be useful to avoid destructive modeling inside SketchUp. SubD is a great plugin to create organic modelling and parametric subdivision inside SketchUp, but creating a parametric openings on SubD meshs is not available .
The Design stage always required a lot of flexibility to create design options. and flexible design tools is important to create better designs in short time. Recently, WrapR has come to SketchUp and it works nicely with SubD and Substance Painter. So let say that we have created an organic shape using SubD and we want to turn this organic shape to a shell with openings, if we drew on the SubD mesh, then we will get a destructive mesh and it will not be editable. So if we create the openings and the shells using a displacement map created by Substance Painter then we not get a destructive modeling at all.

So my suggestion is having an option to create an invert for the displacement so the Mesh would look like a solid, then we could use "Water Level" and "Shift" options to create openings in the mesh.
In the following Image I have used a black and white image to create the windows strips for the tower, that was useful to get a quick design decision.

[Shiyan lin]

Hi, Mousa

It took a long time for me to fully understand what you mean. Interesting idea, we might need some remap ability to transform these height map to minus zero?or we could export 32 bit height map which allow minus zero from substance painter? Is that right?

[Mousa_SA]

Hi Shiyan,

My suggesting should be explained with some images, in the image below, if we want to create a different options for the dome shell, rather than modeling it, we could use a material with displacement, so we could easily change the pattern image and the material size:




Here is the material settings:


The problem is if we look from the inside, the geometry will look as mesh surfaces (not a solid):



So my suggestion is if v-ray could generate an inverse mesh with the original one at the same time one so we could get a solid shell:

+= Solid

Creating like this types of geometries by using displacement is a Ram consuming, and that will increase rendering time , maybe in the future some enhancement could come to how the displacement works and how it's calculated, then this feature request could be implemented.

[Peter.Chaushev]

Hello, Mousa,
You should be able to achieve the effect you are looking for by applying the same displacement to two faces with the same position and opposing normal vectors.
The jagged displacement edges, however, cannot be amended in the current V-Ray for SketchUp version. This will be resolved in the next feature update which will contain displacement improvements.

Kind regards,
Peter

[Mousa_SA]

Hi Peter,

Thanks for the tips, it will do the job for now. Maybe if we got something like this in the future it would make the workflow better and easier.
Great to hear that The jagged displacement edges will be resolved in the next feature update. I was thinking on how we could get a precise displacement for an image pattern ( like the image pattern above) without killing the memory and increasing the rendering time, maybe if the edge length could be adapt between 2 input values, so the large areas that have one color could take the large edge length value, and the transitional areas between 2 colors could get the small edge length value (maybe we could input the value for the transitional areas length based on the world unit). That could be similar to how the "Adaptive Subdivision" works in the old versions of V-ray. So that could help to avoid creating millions of triangles in non-necessary areas. Maybe something similar to this is coming in next releases !