3: TEXTURING THE HEART
such a complicated shape in Lightwave is challenging. I decided to create
a spherical UV map of the main section of the heart, because it is roughly
a round shape. The large veins and arteries on the upper part of the heart
are textured with a flat color and a procedural bump map.
I hid the upper tubes coming out of the heart. I then created a new spherical
UV texture for the bottom section of the heart. This is done by clicking
on the "T" button at the lower right of the Modeler window and
then choosing "New UV map" from the popup menu next to the button.
of the complicated shape of the heart, there are some overlapping polygons
in the UV map. To fix this I moved some of the points in the UV map around
to remove the overlap and also to make the map fit the UV space exactly.
This image shows the original map in the background and the adjusted map
in the foreground layer.
I needed a guide image that showed were the modeled arteries intersected
the surface of the heart, so that I could paint color and bump maps that
matched the arteries. I copied the heart to a new layer and subdivided
it. I made this guide image by using the Solid Drill command to drill
the shape of the arteries into the copy of the heart. This image shows
a subdivided copy of the heart with the 3D veins in a background layer.
I have just used the solid Drill command to stencil the veins onto the
operation also cuts the UV map, showing where the arteries fall on the
UV map. I exported the UV map as an EPS file and used the EPS file in
Photoshop and Illustrator as a guide for creating the textures
This images below shows a section of the color and bump maps. I painted
a layer of fat around the arteries. On top I painted smaller arteries
branching off from the modeled ones.
I also made a mask texture to blend between the UV texture and the base
color of the heart. Here I have loaded the mask as a backdrop to the UV
map. The black areas are the holes in the map where the large tubes connect
to the main body of the heart.
This examples shows how the color texture map is applied to the heart.
Although the idea is simple I find it a little hard to explain clearly
how to blend textures together so I drew a crude diagram below to illustrate
the base color for the tubes that connect to the heart and the main body
of the heart are made to be the same.
Next, working on the heart texture in the texture editor, the color
image is applied to the heart using UV mapping. Then the mask image is
applied as a layer on top of the color layer and the blending mode of
the mask is set to "Alpha". Wherever there is black in the mask,
the color layer below will be masked, allowing the base color of the object
to show through. Since I have made the base color of the heart the same
as the color of the large arteries and veins that attach to it, the arteries
and veins appear to blend smoothly into the heart texture
was not happy with the flaps on the heart that covered the left and right
atriums. I cut these parts of the model away and recreated them. I textured
these separately with image maps below.