box + displacement map problem

[wojtek-w]

Hi,
when i apply material with displacement map to a cube, as a result i got six planes moved along its normals and not connected (so it's not a cube anymore) Shoulden't the shader displace only non-black areas of a displacement map instead of all surface? Is it a normal behavior or am i doing something wrong?
SU 7 Skindigo 2.2.12
I'll appreciate all help.

[Pibuz]

I'd appreciate an image to see the problem.
Help us in helping you

[fenerolina]

I use to solve this problem by rounding the box cornes, even if its very few ,and smooth the edges . So when I click one face of the cube all the faces are selected as 1 texture instead of 6. Try it and post some images..

[wojtek-w]

sorry i assumed all is clear.
I've just done test renders to show this issue and somehow the efect is different then yesterday when my question was born but still other then expected.
So first material preview with albedo map used for displacement and other one with external contrasted bw version of texture. Difference isn't big but visible. Displacement scale is set to 0.03 I hope now it's clearer. (btw how to save bigger preview?)
Then those 2 matrials applied on model. Cube is 300cmx300cmx300cm
Then a render i'v got yesterday (another scene - cube size 600x600x600 but displecement scale still around 0.03 (i'm not sure but not less then 0.03 and not bigger then 0.05) and the same external map of displacement ) - corner is quite straight but empty.
So my question is - is it possible to obtain not flat material but with no empty corners ?

[wojtek-w]

I use to solve this problem by rounding the box cornes, even if its very few ,and smooth the edges . So when I click one face of the cube all the faces are selected as 1 texture instead of 6. Try it and post some images..

thx for the tip. I'll try this.
so it's only a question of modeling technique? material behavior is normal ?
But still i don't understand why this time the surface is more "bumpy" than yesterday with sme displacement scale...

[galinette]

That's strange. I would expect this if your cube is exported as six independant squares, each having its own vertices. But for a regular cube where faces share eight vertices, this should not work like that.

Could you show the part of the igs containing the cube mesh?

Etienne

[wojtek-w]

Could you show the part of the igs containing the cube mesh?

Etienne

sorry for the stupid question but - how?

and also isnt't the box in material preview a cube with 8 vertices?

[Whaat]

I'm afraid that the SkIndigo cube preview scene cannot currently be used to preview displacement because it contains no subdivision settings.

In your scene with the box, be sure to use high enough subdivision settings. You probably need your max subdivisions set to about 10 for this scene.

A cube is tricky for subdivision because the edges will rip apart unless the face vertices share the same UV coordinate and the same normal. This can be accomplished by:
- positioning the texture on a face using the SketchUp texture positioning tools
- using the SU ink dropper to copy the texture position to an adjacent face (This makes the face vertices share the same UV coordinates)
- select all edges in the cube and 'soften' them using the SketchUp soften edges dialog. (This makes the vertices share the same normal)

If you follow these steps, the seams of your mesh will not rip apart.

[wojtek-w]

thank You very much Whaat. I'll try this.

[Termin8]

Hi all,

I have the same problem, but in Cinema 4D. Is there a standard workflow (hi subdivision, converting objects etc.) that i must go through to achieve better results? My trial/error method didn't give me the exact understanding of the procedure. Can enyone help please?

Thank you!

Regards,
Alexander