I know that having overdrawn pixels is not desirable as well as having many polygons since they can decrease performance. Often when I model I have an option to decrease the number of polygons by having disconnected polygons over. For example, considering this:fieled textured Let's imagine it has more turns that are not visible in this picture. I can decrease the number of polygons by having a pathway as a single disconnected face: enter image description here As a result I would have less poly-count, but the bottom geometry would be overdrawn in many areas.
Or I can model this as a single continuous mesh. As a result I would have more poly-count, but no overdraw: enter image description here I very often have similar situations and I'm wondering which of these would be more performance efficient and cause less performance decrease on mobile devices?

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    \$\begingroup\$ Whatever is under the grass is only processed by the vertex shader, the resulting fragment of the road is only that which you can see. Also the difference here seems so minimal that I don't think it will impact anything. Just profile the game in later stages you can always go back and modify the roads if you have to. Although one mesh probably means less drawcalls unless you batch them in a way. \$\endgroup\$ – Sidar Mar 18 '19 at 21:36
  • \$\begingroup\$ Thank you for your answer @Sidar \$\endgroup\$ – blablaalb Mar 18 '19 at 21:51
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    \$\begingroup\$ The answer to every question "Which is faster, A or B?" is to whip up a test case of each one, reflective of your needs and profile the options. This way you get real data that's accurate for your use case, in your application context, on your target hardware, with no Internet hearsay. We can easily create scenes that are vertex-bound. We can easily create scenes that are fillrate-bound. We can easily create scenes that are neither. Which case is more likely to arise in the context of your full game is something only you can answer accurately, since you have your whole project to profile. \$\endgroup\$ – DMGregory Mar 18 '19 at 22:07
  • \$\begingroup\$ @Sidar Not always. If he draws the road first then the grass, then both will be processed by the fragment shader. Not like it actually matters, since (and I'm adding to DMGregory's comment too) I doubt you can even profile it at this point, the difference must be down to microseconds \$\endgroup\$ – Bálint Mar 18 '19 at 22:21
  • \$\begingroup\$ That's true, am assuming the engine sorts by depth though \$\endgroup\$ – Sidar Mar 18 '19 at 22:22

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