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kcgameslod [2020/04/28 17:04] – created windsorkcgameslod [2023/04/04 09:17] (current) – steph.jorgensen
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-====== Level of Detail ======+====== Level of detail ======
  
 "Level of detail" (LOD) refers to decreasing the complexity of a model as it moves away from the camera. A model that is far away doesn't need to have as much detail as one that is close. Reducing complexity in this fashion reduces the load on rendering hardware, allowing many more models/trees to be rendered on screen at the same time. "Level of detail" (LOD) refers to decreasing the complexity of a model as it moves away from the camera. A model that is far away doesn't need to have as much detail as one that is close. Reducing complexity in this fashion reduces the load on rendering hardware, allowing many more models/trees to be rendered on screen at the same time.
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 Certain SpeedTree products include automatic, dynamic LOD generation. The LOD is "dynamic" because it changes smoothly as the distance to the tree changes, hiding any geometry "pops" that discreet LOD levels would otherwise cause. Certain SpeedTree products include automatic, dynamic LOD generation. The LOD is "dynamic" because it changes smoothly as the distance to the tree changes, hiding any geometry "pops" that discreet LOD levels would otherwise cause.
  
->**Note**: Automatic Level of Detail is a feature included only in the SpeedTree products for real-time use (SpeedTree for Games, UE4, Unity, Lumberyard, etc.). SpeedTree products for VFX (Cinema, Studio, etc.) do not include LOD and should instead use [[kcresolution|Resolution]].+>**Note**: Automatic Level of Detail is a feature included only in the SpeedTree products for real-time use (SpeedTree for Games, UE4, Unity, Lumberyard, etc.). SpeedTree products for VFX (Cinema, Studio, etc.) do not include LOD and should instead use [[kcvfxresolution|Resolution]].
  
 ===== Previewing LOD ===== ===== Previewing LOD =====
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 To turn on LOD for a tree, select the [[tree_generator|Tree Generator]] and tick the "Enabled" property in the [[tree_generator#dynamic_lod|Dynamic LOD]] property group. You can also set the number of LOD levels with the "Number" property. To turn on LOD for a tree, select the [[tree_generator|Tree Generator]] and tick the "Enabled" property in the [[tree_generator#dynamic_lod|Dynamic LOD]] property group. You can also set the number of LOD levels with the "Number" property.
  
-When you do this, an LOD control will appear in the bottom-left of the [[tooltree_window|Tree Window]], shown to the left. By default, the slider is in "Manual" mode. If you drag the arrow up and down in the LOD control, the tree will dynamically change LOD. You can see the polygon counts update as this occurs.+When you do this, the LOD indicator will appear in the bottom-left of the [[tooltree_window|Tree Window]], shown to the left. By default, the slider is in "Manual" mode. If you drag the arrow up and down in the LOD control (or hold CTRL while dragging the left mouse button up and down), the tree will dynamically change LOD. You can see the polygon counts update as this occurs.
  
 Clicking the "..." button at the bottom of the LOD control allows you to switch the LOD mode from "Manual" to "Screen Area." This will disable any mouse input on the control, but the tree will dynamically change LOD as you move the camera nearer or farther away. Clicking the "..." button at the bottom of the LOD control allows you to switch the LOD mode from "Manual" to "Screen Area." This will disable any mouse input on the control, but the tree will dynamically change LOD as you move the camera nearer or farther away.
  
-===== Global Settings =====+===== Global settings =====
 During an LOD transition, parts of the tree will be removed intelligently to reduce complexity but keep the transition seamless. This is done by analyzing the tree to see which parts are hidden in the interior. A part that will be removed shrinks until it is invisible before the geometry is completely removed in the next LOD level. During an LOD transition, parts of the tree will be removed intelligently to reduce complexity but keep the transition seamless. This is done by analyzing the tree to see which parts are hidden in the interior. A part that will be removed shrinks until it is invisible before the geometry is completely removed in the next LOD level.
  
 For example, branches will shrink away to their spine before ultimately going away (see below). Leaves shrink away in a similar fashion, but other leaves also grow to maintain the tree's silhouette. For example, branches will shrink away to their spine before ultimately going away (see below). Leaves shrink away in a similar fashion, but other leaves also grow to maintain the tree's silhouette.
  
-{{ :lod2_small.jpg?800 }}+{{lod2_small.jpg?800}}
  
 To control how many parts are removed at a global level, use the [[kccurves#lod_curves|LOD curves]] property in the [[tree_generator#dynamic_lod|Dynamic LOD]] property group in the [[tooltree_window|Tree Generator]]. With these curves, you are controlling the reduction over the course of the tree's total LOD transition. There are a number of these properties, to control the reduction of different geometry types in the tree: branches, leaves, decorations, etc. To control how many parts are removed at a global level, use the [[kccurves#lod_curves|LOD curves]] property in the [[tree_generator#dynamic_lod|Dynamic LOD]] property group in the [[tooltree_window|Tree Generator]]. With these curves, you are controlling the reduction over the course of the tree's total LOD transition. There are a number of these properties, to control the reduction of different geometry types in the tree: branches, leaves, decorations, etc.
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 Using "Grow Scale" and "Jumble" are key to maintaining the silhouette and keeping the "fullness" of the tree: Using "Grow Scale" and "Jumble" are key to maintaining the silhouette and keeping the "fullness" of the tree:
  
-{{ ::leaf_lod.jpg?700 |}}+{{leaf_lod.jpg?700}}
  
  
-===== Individual Settings =====+===== Individual settings =====
  
 In addition to the global settings, there are additional settings on each [[kcgenerators|Generator]] for dealing with LOD. With these, you can fine-tune LOD changes to be more seamless, or reduce complexity in a more aggressive manner in places that won't be seen. In addition to the global settings, there are additional settings on each [[kcgenerators|Generator]] for dealing with LOD. With these, you can fine-tune LOD changes to be more seamless, or reduce complexity in a more aggressive manner in places that won't be seen.
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 Branches and fronds can change their segments with LOD, reducing the complexity of the geometry even if it stays in the tree. This can be done explicitly for length or radial segments, or you can adjust the "Optimization" property so the Modeler will intelligently decide where to remove segments to keep the same overall shape. Branches and fronds can change their segments with LOD, reducing the complexity of the geometry even if it stays in the tree. This can be done explicitly for length or radial segments, or you can adjust the "Optimization" property so the Modeler will intelligently decide where to remove segments to keep the same overall shape.
  
-{{ ::optimized_segments.png?nolink |}}+{{optimized_segments.png?nolink}}
  
 >**Note**: Too much segment reduction, especially in length, can cause visible pops. Preview the LOD switch to make sure this isn't noticeable. >**Note**: Too much segment reduction, especially in length, can cause visible pops. Preview the LOD switch to make sure this isn't noticeable.