[Done] Sphere with weird displacements?

[brknbrkn]

Hello all,

I created this 'mushroom' model and by looking at the model you can see its showing weird displacements, even in the render.
Is this normal and if so, how can I make it disappear. Applying a smooth/soften edges on this object isnt possible for some reason.

[TIG]

How big is the object?
Do you have any internal 'partitions' ?
Are edges hidden rather than smoothed?
Switch on View > Hidden Geometry and select one, and use Entity Info to see...
Use a section-cut to get 'inside' and erase any 'partition' faces.
Unsmooth everything and unhide any hidden edges etc.
Then smooth again to see if that helps...

[Rich O Brien]

You simply need more geometry. Also most sketchup render apps require you to group/component geometry to apply a smoothing in the render.

But if your initial geometry is incredibly lo poly then then smooth will only get so far.

[Gaieus]

@rich o brien said:

You simply need more geometry.

Yes, the initial shape looks rather low poly fora really smooth render (especially for a close-up)

@unknownuser said:

Also most sketchup render apps require you to group/component geometry to apply a smoothing in the render.

This is also very important for many rendering apps.

[brknbrkn]

Thanks for the replies, here is a screen of the geometry. It is grouped btw but after smoothing nothing changes.

[xxl-img:139mev01]http://www.efpp.nl/mush3.jpg[/xxl-img:139mev01]

How would one create more geometry?

[cotty]

It is often possible to define the subdivision (=smoothing) while exporting for the renderer...

[gilles]

@unknownuser said:

How would one create more geometry?

when you select arc tool, circle tool or polygone tool you can type the amount of segment then Enter.
if your arc.. is already drawn and not connected to other geometry you can change the amount of segment in entity window.
if you draw an arc... type 24s ( for example) + Enter before doing another action.

note: you must have an inner face in your shape

[brknbrkn]

Thanks Gilles, really helpfull that.

[ArCAD-UK]

I've just mocked up a half sphere and scaled it to be similar to your object with the same number of faces and it looks totally smooth. Couple of things to check...

1 Go to window>Soften Edges and make sure "smooth normals" is checked and the "Angle between normals" is at a suitable figure of typically between 20 - 30 degrees.

2. Look at the object in "Monochrome" mode and check all your faces are the correct orientation. If not they could be affecting the rendering.

The only other aspect would be your construction method. Could something have distorted the geometery?

[brknbrkn]

I fixed it by using more segments. Thanks for the comments and help!

[notareal]

This is a known problem; "terminator* artifact". It's Really Not a Rendering Bug, You See…

@unknownuser said:

The terminator problem results from improper selfshadowing due to planar-polygon approximation of smooth
surfaces. This problem extends to mirror reflection, refraction, and Gouraud shading,

Fortunately some render engines can handle these models

Issue with commonly used fix; polygon count increases from left to right.

Treatment by Thea Render, no need to increase polygon count.

Page not found - Thea Render

Thea Render (www.thearender.com)

*A terminator is an area on a surface separating lit and selfshadowed
areas.

[Gaieus]

@notareal said:

Treatment by Thea Render, no need to increase polygon count.

This is indeed a great feature of Thea I remember when it was introduced and can help a lot with low poly models - howeve note that th perimeter f the shape can still give a low poly onject away so there should still be a good balance between poly count and applying such advanced technology.

[notareal]

True, low polygon model is "faceted" with the silhouette. Like in examples... there is nothing that can be done for it with selfshadowing. Only subdivision will help for that.