How to reduce polygons in Blender

 Too many polygons can have a big impact on performance. In particular, the assets used in the game have strict polygon restrictions and must be kept within about 60,000 polygons. However, manually deleting the vertices is tedious.

Rest assured, Blender has a feature that automatically reduces polygons! There are three main ways to reduce polygons like :

• Decimate modifier
• Remesh
• Retopology with Shirink Wrap

So how to reduce polygons with Blender?

Blender Decimate modifier

The easiest way to reduce polygons with blender is to use the Decimate modifier. Select the object you want to reduce polygons and add the blender decimate modifier from the properties on the right.

Slide the Ratio to adjust the amount of polygon reduction.

Once you have decided how much to reduce, apply with the arrow next to the modifier.

The nice thing about the Decimate modifier is that you can reduce polygons without breaking the blender UVs. Models that are already textured are advised to reduce polygons this way.

Blender Remesh Tool

A blender remesh function was added from the middle of Blender 2.8. By using this, you can remesh the polygons so that they are lined up neatly.

You can choose between Voxel and Quad, but the original model will have a different remesh finish. Let's use it properly according to the situation. Quad takes a little longer to process.

Depending on the original object, there may be more polygons after remeshing. Also, all blender UV is lost. It's best not to use it much for models that already have blender textures.

Since the polygons are evenly spaced, it is suitable for manually deleting vertices. It is good to dissolve the edge with ctrl + x and pull out the edge while considering the silhouette.

Retopology with Shrink Wrap

I don't usually use it too much (because it's troublesome ...), but the quality is the highest. Use this method, especially for blender character models where mesh flow is important. On the other hand, if the model does not require mesh flow, it will be very inefficient.

To retopology with ShrikWrap, create a new object (a plane is a good choice) and set the ShrinkWrap modifier on the newly created object. Then, specify the model of the remesh source in Target.

After that, I will cut out polygons while being aware of the mesh flow. You can see how the polygons stick to the original model.

You can think of this method as almost a new remodeling. This workflow is only useful when using sculpt modeling. Please note that this method is not recommended for beginners at all.

summary

To reduce polygons count with blender, we generally use these three techniques. Each method has its strengths and weaknesses. Let's use each method properly according to the purpose.