VRay for SketchUp Manual
Adding a Bump
Although we can use Bitmap for most materials of the objects, some textures
like wall surfaces, tile, wood, oil painting, leather and water, which all have
an uneven surface, must use Bump map in order to create them.
1. Click on the brick cube and open the
Material Editor to edit the Bump map to the brick material. Under the Maps from
the right side of the Material Editor, check the Bump and click on the "m" to
open the Texture Editor.
2. Same as before, select Bitmap under
the Type pull down menu.
3. Click on the "m" to the right of
Bitmap, select the appropriate grey-scale bump map texture for the brick.
4. After importing the map, if the Bump
map is the same as the Diffuse map, make sure the U, V Repeat under UVW
Transform have the same value. For example, if Bump map is using U: 2 and V: 2,
the Diffuse map should be the same. Otherwise, these two maps will not align
correctly. Also, start the Multiplier on the left side with value like 1 and
increase as necessary.
Image on the left is result of using only brick Bitmap. The surface of the
block looks very smooth. Image on the right is rendered with Bump map added to
the entire block. Obviously you can see the Bump texture within the brick
And also, earlier we talked about using Reflection>Glossiness to adjust
reflecting material's glossiness and create frosted look of the object. If add a
little bit of Bump map to it now will make the object look even better.
Image on the left is using only Glossiness from Reflection setting. Image on
the right has Bump map added to it.
Below are some examples of textures created with Bump map.
|Bump map is created using the grayscale of
the Bitmap to set the high and low texture. The bright part of the
Bitmap is considered as the high part and the dark is low. The Bump map is
seen more clearly at the part where the object reflects most of the
light. Using a Bump map texture to create bumped texture is only a visual
effect, not the true surface of the object. Look at the edge of the
object and you will still see the smooth surface.