Exporting the Asset
This doc goes into finalizing your asset before export to make sure your asset is ready for use in a game engine...
Last updated
This doc goes into finalizing your asset before export to make sure your asset is ready for use in a game engine...
Last updated
There are many steps when creating a 3D Asset, and it can be very annoying when you import your asset into a game engine and it not look great or work correctly.
This document will go over all the things you should check and confirm before exporting your asset in order to reduce any issues later on. These elements are introduced early so that you start creating good habits on export.
One of the most common issues when moving your asset from your 3D Creation Tool to a Game engine such as Unity is the asset scale. There is a reasonably high chance that the scale of your asset has been changed, so even if it says it is the right size there is a fair chance that the scale is not. A 10 metre asset at 0.1 scale will be imported at 1 metre in the game.
You can see the scale (as well as position and rotation details) at the top right of the viewport. If you cannot see this, you can select the Arrow at the Top Right of the Viewport or press [N].
If the scale is not X: 1.0, Y:1.0, Z: 1.0 you will need to apply the transforms so that it is reset to the correct scale.
In 'Object Mode', go to 'Object menu > Apply > Scale' at the top left of the Viewport, or
Use [Ctrl + A] and select 'Scale'.
You can also use 'All Transforms' to reset Position, Rotation, and Scale. Note that if you do this the Pivot location may change.
It is strongly recommended to Apply Transforms before exporting your assets. Scale, in particular, is very important otherwise you will most likely have scale issues within your game engine.
As most game engines will render only one side of a polygon in order to save processing you will need to make sure that your polygons are facing the right way, otherwise some of your asset may be invisible.
As mentioned in previous tutorials, each polygon has a normal, or a direction perpendicular to the polygon. If this normal is facing the right way, it will be visible in game. If the polygon is facing the wrong way, it will not be visible.
It is very common for your assets normals to be flipped in the process of creation. Blender has a tool that allows you to easily visualise the normals facing direction.
Select the pulldown on the 'Overlays' icon at the top right.
Toggle 'Face Orientation' in order to see the Normal direction.
Blue is visible and Red is invisible in the game engine (unless specified otherwise).
There are two approaches to flipping normals, one approach is to recalculate all the normals at once, which works for most normals, or you can manually flip selected polygons.
Go into Edit mode [Tab], Polygon Select [3], and select all the polygons.
Make sure X-Ray mode is on in order to select polygons behind others.
Go to 'Mesh Menu > Normals > Recalculate Outside'.
You can use [Shift + N] to do this.
Select any Polygons that are still Red.
Go to 'Mesh Menu > Normals > Flip' to flip any normals manually.
With the asset made you may want to get it into a game engine. Much like JPG and GIF for images, there are many formats for 3D Assets.
FBX - this is the most common format to current game engines as it supports most features like animation without issue.
GLTF - this is a format that is growing in popularity due to its strict standards. It is useful in WebGL or NFT ecosystems.
USD - Is another format that is becoming more common due to its support of all the features, but is usually a larger file size. This is more common in previsualization and animation/VFX.
OBJ - an older format can be used in many engines, but has limitations, and therefore is not that common.
FBX is the most common to go with so we will use that. As noted, scale can be an issue and to reduce issues even further we will add a step or two in the export process.
In 'Object Mode', select the assets you would like to export as one file.
Confirm that the pivot location is correct, and Rotation and Scale settings are reset to 0,0,0 degrees and 1, 1, 1 scale.
Go to 'File Menu > Export > FBX (.fbx)'.
Select the target folder destination.
Name the asset.
Select 'Limit to > Selected Objects' at the top right of the window.
Confirm that the Transform > Scale is 1.00.
Change the 'Transform > Apply Scalings' pulldown to 'FBX All'.
This may reduce potential scale issues when importing the asset into game engines like Unity.
Select 'Export FBX' a the bottom right of the Export window.
In this tutorial we made sure the final asset was ready to export with Smoothing, correct Pivot location, rotation and Scale, correct Normals, and reasonable polycount before exporting the asset itself.
[Ctrl + A] - Apply Transforms options.
[Shift + N] - Recalculate Normals
And thats it! You have completed your first 3D asset. With that we can go over all the hotkeys and processes that you can now use.
