Game asset pipeline workflows often depend on the specific asset, preference, the project itself, etc. Sometimes you use one workflow, sometimes another. In some cases you can use the high poly as a base for the low poly, for example when you’re mainly relying on bevels for your high poly shading, it’s easy to remove the bevel modifier, clean up the model and do whatever other things you have to do with your low poly in your pipeline (UV unwrapping, vertex painting, rigging, …). An example of where this type of workflow would work is this asset I made a while ago. You can see the general model doesn’t really have curvy surfaces, so I was able to make the high poly by just using booleans and bevels. However, when you have more organic/curvy models, like this phone, it will probably better to just retopologize it. Remind yourself regularly that the number one priority in your low poly model is getting a decent silhouette. Depending on how low poly you want to go/the purpose of the asset in the game, for this asset just using a cube with a couple loops to adjust it to the silhouette of the high poly. Such as the example attached to this reply. Didn’t really look at ref for the side so shape is probably innaccurate, but you get an idea of what the low poly could look like. You can also go more detailed, if this was an asset the player would hold in his hand and see quite close up, you could indent the screen part, add some buttons popping up in the silhouette, and more geo to round off the rounded corners.
Generally the way you do stuff doesn’t really matter, try some different workflows and see what works best for you, and what gets you the best results. The only thing that matters is what the asset looks like in the end, and that it holds up in the context that it’s supposed to be seen. For example, the phone as a first person “hero” prop would need a higher quality end result compared to if this phone would not be an interactable, laying on some random table in a third person game. For this reason it’s generally a good habit to regularly zoom out to the size your asset would be on screen in the game while creating it, to make sure you don’t get lost in unecessary details that wouldn’t show up anyways.
Unless I know I can easily generate a low poly model from the high poly, I really don’t bother worrying about it since retopologizing high poly assets to create a low poly version is often much faster in my experience compared to worrying and pottentially running into hurdles while trying to keep your high-poly low-poly compatible.
Nokia_3310.blend (1.0 MB)