My bad
"the rule model with only quads" is a general rule acrose all the app's Max ,Maya ,LW ,C4D ,Blender ect ect all the app's follow the quad rule cause there SubD will convert Tri's to quads.

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The Artist that will fight for decades to conquer their media.
Even if you never know their name ,your know their Art.
Dark Sphere Mage Vengeance