Texturing Tips with Tom Greenway



This tutorial was made in 3DStudio max 5 but covers theories and principles only which are relevant to all 3D software packages.

To start, we will set up a very simple scene, the intention is to let the textures and the lighting to the work so all we have for the geometry is 2 planes and 1 sphere, indicated below with 1,2 & 3. The only other objects we have are a skylight, omni light and a camera (4, 5 & 6). If your software doesn't support a feature that creates radiosity and soft shadows such as this 'skylight' you can fake it with an array of many dull standard point (omni) lights placed in a dome formation. Both lights I have here are casting shadows and the omni '5' is the main light source

The image is rendered from the camera and below is the initial result.

Texture colour maps and their matching bumps have been assigned to the 3 objects but that's as far as it's gone, no work as to setting UVW co-ordinates or editing the textures in any way has been performed, the colour map is set to 100% and the bump map to 30%. What you can see below is the usual case of your software stretching the texture to fit these basic geometry shapes as best it can using its default UWV co-ordinates that come with primitive objects.

Again an example of no texture editing with just the colour map applied at 100% and the bump map at 30%:

So now the tutorial will really begin by looking at ways of improving our render by adjusting these textures. The next image show that all of the textures have now been 'tiled' meaning repeated across the objects surfaces. As all the textures on this cd are seamless they should tile very well, but problems can still arise when the repeating parts of the textures become too obvious and for this reason some textures 'tile' better than others.
By tiling the colour maps and their bump maps you increase the detail across the geometry as you can see below.

Next we have the 'repetition texture problem' indicated, but as it is not too severe we will continue with these choices of textures. Also the next stages will break the textures up a little more.

Our second example showing the increase in detail by tiling the texture maps (second sphere):

The next tip could be the most important one here in getting those quality results from your renders. You have to make the textures fit and work with your geometry as much as possible.
The next two renders show the before and after of poorly 'fitted' textures and how we have simply improved them.

Below we have improved these issues by rotating the texture on the floor and then aligning both textures so there is appropriate detail (especially in the 'bump' detail) where the wall meets the floor.
Look especially at this joint, those odd marks that were in the centre of the wall now work very well at the base.

...proceed to page two to learn more...
 

Next we will adjust the texture settings starting by increasing the 'bump' amount. In this example the amount 30% is increased to 60%. The change in this case is very subtle, mainly due to the skylight but subtle changes are by no means a bad thing. This can been seen below (just!). Our third example showing the increase in 'bump' value

The next stage shows a change in the textures specularity. It is always a good idea to try the texture's bump map as the specular map as it can give great results. It is not so apparent in the render but can be much more clearly seen in the textured spheres below this (4th sphere along)

Putting this into practice we apply a second set of UVW co-ordinates to our object for the mask alone. This is rendered out with the mask swapped into the colour map just for the example above.

Now we select a second material to mix in with our first. The new material will show through in the whiter areas on the wall (above) and the result can be seen right.
 
 
 
The next stage is going to introduce the shadow maps and to prepare for this we need to adjust the lighting a little. Shadow maps are mostly used to break up sunlight as it passes imaginary objects that are outside of your scene.

The lighting is changed to prepare for this by turning off the omni light and adding a much brighter spotlight to the scene.

So far so good, what can we do next? Well as you will notice this Texture CD also includes a few extras such as shadow maps and dirt masks, so lets try putting these into use.

The dirt masks are black and white images which can be used to mix textures together. The first texture shows through where the whiter parts of the mask are and the second uses the blacker areas. The shades of grey blend the two together with the amounts of each depending on how light of dark the particular section of the mask is. Most 3D packages will have suitable material types to put this into practice and have names such as 'blend' 'composite' and 'mask'

This spotlight is then set to project the shadow map giving the appearance of shade generated by leaves and branches.

Now you can have some fun, swap textures about, and see what else you can achieve. I have made a simple lathe object, pulled the sphere around a bit, gone for an old wooden boards on the floor and added a depth of field affect onto the camera



Next we will adjust the texture settings starting by increasing the 'bump' amount. In this example the amount 30% is increased to 60%. The change in this case is very subtle, mainly due to the skylight but subtle changes are by no means a bad thing. This can been seen below (just!). Our third example showing the increase in 'bump' value

Depth of field is good for adding realism to your images and also for highlighting a particular area. Above the worn paint on the boards are a good example of this. Depth of field can significantly increase rendering times and (like many effects) its easily overdone, so my final image is back to the original camera, which I think now gives a rather nice result :)

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