I am learning Blender and currently building a simple low poly model. Trying to follow reference picture I realize that it is very difficult to build a model such that all faces are perfectly planar. I can use flattening tool but some quads are never brought to perfect flatness. When tested wih 0.1 deg limit they show nonplanarity.

Even when I scale one face of a standard cube (in its own plane) it is enough to show nonplanarity above 0.01 deg. Similary scaling and/or rotating simple plain is enough to create nonplanarity above 0.02 deg.

I am guessing that this is related to the finite accuracy of numerical representation of the location of vertices. Clearly it makes sense to disregard this level of nonplanarity.

But how about 0.1 deg? 1deg?

  • $\begingroup$ My question is not about the necessity of flatness or how to improve it. I am looking for information when flat is flat enought. For example subdividing mesh will reduce non-flatness but it will still be there, just much smaller. Some expert say that quads have to be flat, period, (that is perfect). Intuitively perfect flatness should not be required. If we accept some curvature mesh construction is easier and number of polygons lower. $\endgroup$ – PeterM Oct 29 '19 at 18:13
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    $\begingroup$ Enough for what purpose? How are you measuring the reported planarity? $\endgroup$ – Robert Gützkow Oct 30 '19 at 19:24

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