README.md

Focus Wizard Tutorial

It's so good to know you are still interested in this add-on. Keep it up! You'll soon master effective lodding. For now, you can find a Blender file called Monkey-with-Teapot.blend in this folder. Open it in Blender and read this guide to get a practical example of using the built-in presets.

As discussed in the User Guide, T1nk-R Focus Wizard is shipped with two sets of presets, called the Direct presets and the Cascaded presets. As also explained, the two only differs in how modifiers shall be composed for logging.

The Blender file has two collections, Working with Direct Presets and Working with Cascaded Presets. You are more than encouraged to try what is written here, and you can also test what results you get by applying the other set of presets. This may help in understanding how things go.

Enable T1nk-R Focus Wizard

To get up and running:

1. If you haven't done so, head to https://github.com/gusztavj/Focus-Wizard and download the latest version of the add-on.
2. Install the add-on.
3. Enable the add-on
4. Load the Blender file and feel free to look around.

In both examples, we have a scene with a monkey and a teapot, and we want to create 4 additional lod levels. You'll learn how easy it is to view each lod with this add-on.

Working with Direct Presets

Now you'll work with the collection named Working with Direct Presets.

First of all, hide all other collections and set the scope of T1nk-R Focus Wizard to this collection to make sure the visibility of objects outside this collection is not affected. To select the scope:

1. Click the icon or anywhere in the Root Collection field.
2. Select Working with Direct Presets.

Select scope

The collection contains 3 objects, a monkey and two teacups, each tagged, as shown below:

A screenshot of the example file with object names shown in the Outliner

The Monkey for Direct Presets

The tag #lod0-4 in the name of Suzanne for Direct #lod0-4 means we plan to use this Blender object for all lod levels. If you open a Properties editor and switch to Modifiers, you'll see the following:

Modifiers defined for the monkey

The idea here is that we create a separate Subdivision modifier for lod 0, 1 and 2, and a Decimate modifier for lod 4. Subdivision modifiers refine geometry differently, the higher the level of details, the higher Levels Viewport is. The Decimate modifier will reduce geometry. The base mesh without any modifiers applied (the monkey as it was created) belongs to lod 3. That is, for lod 3 we don't need any modifiers, and that's exactly why you can't notice any modifiers tagged with #lod3.

Before you learn how to set up your stuff to work like charm, first take a look at this short demo to find out what ease of switching you can gain.

T1nk-R-Focus-Wizard-for-Blender-Demo.mp4

How Modifier Rules for Direct Presets Work

• When you switch to Direct: Lod 0 in Select Preset of T1nk-R Focus Wizard, the Subdivision #lod0 modifier will be made visible and the others will be hidden.

  Only the #lod0 modifier is visible

  Take a look at the objects themselves and you'll find the most detailed version there.

• When you switch to Direct: Lod 1 in Select Preset of T1nk-R Focus Wizard, the Subdivision #lod1 modifier will be made visible and the others will be hidden.

  Take a look at the objects, again, and you'll find a less-detailed version:

  Difference in details between lod 0 and lod 1

• When you switch to Direct: Lod 2 in Select Preset of T1nk-R Focus Wizard, the Subdivision #lod2 modifier will be made visible and the others will be hidden.

• When you switch to Direct: Lod 3 in Select Preset of T1nk-R Focus Wizard, no modifiers will be shown for the object. If you take a look at the Selected Preset section after switching to this preset and take a look at the value of Modifiers to hide, you'll notice the following rule: #lod[01245]$|#lod.*-[012]|#lod[4]-.

  Check the Modifiers to Hide rule of the current preset

  The first part, #lod[01245]$ means that if the name contains #lodn where n is either 0, 1, 2, 4 or 5, the modifier will be hidden. All of the modifiers match this rule, therefore all will be hidden.

• When you switch to Direct: Lod 4 in Select Preset of T1nk-R Focus Wizard, the Decimate #lod4 modifier will be made visible and the others will be hidden.

The Teapot for Direct Presets

Teapot is elaborated a bit further to show you an example where you want to manually intervene to topology reduction at some point instead of pushing sliders of modifiers all the way down or up. Look both objects separately by turning their visibility on an off. The idea is that from lod 3 we don't need the handle of the pot, the lip and the handle of the potlid, assuming that they won't be noticeable from that distance, and therefore we can reduce their geometry to 0 triangles by simply removing them.

This is example shows that you have one object representing the same part of your scene or model for some lod levels, and another for other lod levels. Hence the names, Teapot for Direct #lod0-2 indicates this object will be shown for lod 0, lod 1 and lod 2, while Teapot for Direct #lod3-4 will be shown for lod 3 and lod 4.

If you take a look at the Objects to show by name and Objects to hide by name rules of, for example, the Direct: Lod 1 preset, you'll see that:

• Teapot for Direct #lod0-2 matches the Objects to show by name rule #lod.*1|#lod0-, namely the #lod0- part, and this will make the object visible.
• Teapot for Direct #lod3-4 does NOT match the Objects to show by name rule #lod.*1|#lod0-, as it neither contains 1, nor starts with #lod0-, and this will NOT make the object visible. (In itself, this rule won't make it invisible if it would be visible for any reason.)
• Teapot for Direct #lod0-2 does NOT match the Objects to hide by name rule #lod[02345]$|#lod[234]-, as the character after #lod is not 0, 2, 3, 4 or 5 (but 1), therefore this rule will NOT make the object hidden.
• Teapot for Direct #lod3-4 matches the Objects to hide by name rule #lod[02345]$|#lod[234]-, as the character after #lod is not 3, therefore this rule will make the object hidden.
• At the end, Teapot for Direct #lod0-2 will be visible for preset Direct: Lod 1, while Teapot for Direct #lod3-4 will be hidden.

For the two teapots, we use similar techniques than for the monkey:

• Teapot for Direct #lod0-2 has two modifiers, one refining the base geometry for lod 0, and another reducing geometry for lod 2. For lod 1, we'll use the object as it was created, with no refining, no reduction of topology.
• Teapot for Direct #lod3-4 has two modifiers, one applied in all cases (not matching any hiding rules). Having such a modifier is not mandatory. The reason we added is that we could reduce the geometry of what remained from the teapot further without significant changes in its shape. The other modifier added to this object will be shown for lod 4, yielding in basically the outline of the pot.

Working with Cascaded Presets

Now you'll work with the collection named Working with Cascaded Presets.

First of all, hide all other collections and set the scope of T1nk-R Focus Wizard to this collection to make sure the visibility of objects outside this collection is not affected. To select the scope:

1. Click the icon or anywhere in the Root Collection field.
2. Select Working with Direct Presets.

Select scope

The collection contains 3 objects, a monkey and two teacups, each tagged, as shown below:

A screenshot of the example file with object names shown in the Outliner

The Monkey for Cascaded Presets

The tag #lod0-4 in the name of Suzanne for Direct #lod0-4 means we plan to use this Blender object for all lod levels. If you open a Properties editor and switch to Modifiers, you'll see the following:

Modifiers defined for the monkey

This is how cascading is different from the other technique. Now we want to combine the effects of modifiers. You can notice that we have an initial Subdivision operator to refine default topology for lod 0, and then we add a Decimate operator for each lod level from 1 to 4. Each Decimate decreases geometry to some degree, and their effects is combined: if you switch to lod 3, for example, Subdivision (base), Decimate #lod1 (with un-subdivision of 3 iterations), Decimate #lod2 (with un-subdivision of 2 iterations) and Decimate #lod3 (with un-subdivision of 2 iterations) will all be shown, meaning that you apply a decimation of un-subdivision with 3 + 2 + 2 = 7 iterations.

How Modifier Rules for Cascaded Presets Work

• When you switch to Cascaded: Lod 0 in Select Preset of T1nk-R Focus Wizard, the Subdivision (base) modifier will be made visible and the others will be hidden, as there is no rule for showing modifiers defined (which means all modifiers shall be visible initially), and Subdivision (base) does not match the hiding rule (it doesn't even contain the string lod), while all other modifiers match the hiding rule (the first part of it).

• When you switch to Cascaded: Lod 1 in Select Preset of T1nk-R Focus Wizard, the Subdivision (base) and the Decimate #lod1 modifier will be made visible and the others will be hidden as all other match the modifier hiding rule.

• When you switch to Cascaded: Lod 2 in Select Preset of T1nk-R Focus Wizard, the Subdivision (base), the Decimate #lod1 and the Decimate #lod2 modifier will be made visible and the others will be hidden.

  This is where you can first notice easily that the effects of the two modifiers are combined. Having this preset set, feel free to show/hide Decimate #lod1 to see the changes.

  Cascaded modifiers and the effect of turning off the lod1 modifier

  If you turn off the modifier for lod1, the object's geometry won't be reduced that much.

• When you switch to Cascaded: Lod 3 in Select Preset of T1nk-R Focus Wizard, Subdivision (base) and the #lod1, #lod2 and #lod3 modifiers will all be applied.

• When you switch to Cascaded: Lod 4 in Select Preset of T1nk-R Focus Wizard, all modifiers will be applied.

The Teapot for Cascaded Presets

To make the long story short, construction of the teapot is very similar to how we constructed it for the direct preset. The key difference is that we have added a Decimate #lod1 modifier to Subdivision #lod0 and Decimate #lod2 modifiers for Teapot for Direct #lod0-2, and changed some modifier parameters.

• For lod 0 to 2, Teapot for Direct #lod0-2 will be shown, with the #lod0 modifier shown for lod 0, the #lod0 and #lod1 shown for lod 1, and the #lod0, #lod1 and #lod2 modifiers shown for lod 2.

• For lod 3 and 4, Teapot for Cascaded #lod3-4 is gonna be shown with Decimate (base) displayed for lod 3, and both displayed for lod 4.