Material Settings

CreatiCode

Prerequisite

Adding Boxes to a 3D scene

Introduction

Materials control the look of a 3D object. You can use this block to change the settings of a material:

Wireframe Mode

An object’s skin is made of “meshes”, which are small triangle faces. To reveal these small faces, you can set a material to the “wireframe mode”. The faces will become transparent, and you would only see the “wires”, which are the edges of the faces.

Draw Back Face

The surface of a mesh has 2 sides: the front face (facing outside) and the back face (facing inside). By default, the back face is not drawn, but you can change the setting to draw the back face as well.

In this example, a green box is outside a 6-colored box. When we move the camera inside the green box, we can no longer see its 6 faces. However, if we change the material setting to draw the back face, then we will see the inside faces of the green box.

Z-Fighting and Z-Offset

When 2 objects have overlapping faces, the 3D engine would try to draw both of them at the same time, so we see some flickering effect as these faces “fight” each other. This is called “Z-fighting”.

To avoid this issue, we need to tell the 3D engine which face should be drawn later, so it will win over the other faces drawn earlier. This can be done by setting the “Z-offset” of a material, which can be 0, -1, -2 or -3. The lower the Z-offset, the later that face will be drawn. And it works for all directions, not just in the Z direction.

Log Depth

This is an advanced parameter. It means we use the logarithmic of the distance of objects from the camera to calculate which object should block which other objects. You can keep it as “No” by default.

When the scene is very large, and you see “z-fighting” issues, then try to set this parameter to “Yes” for those objects having the “z-fighting” issue.

Transparency

This parameter controls whether we allow transparency. For example, sometimes a model object is partially transparent, and you want it to be completely opaque. Then you can using this block to set its transparency to “No”.