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New auto-LoD formula

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Avoid the sudden transitions that characterize the old formula.
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Alayan 2024-05-13 22:05:03 +02:00
parent 0f719d0cc5
commit 10943ac0ff
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1 changed files with 23 additions and 24 deletions
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src/graphics/lod_node.cpp
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@ -203,38 +203,37 @@ void LODNode::autoComputeLevel(float scale)
// 1.) beyond which distance the object should disappear entirely
// 2.) at which distances we should switch between a lower-quality model and a higher quality model,
// if these distances are too low we stick to a lower-quality model
// To do so, we use a mix between a power 2 (quadratic) formula and a power 4 formula.
// Step 1 - We try to estimate how far away we need to draw
// This first formula is equivalent to the one used up to STK 1.4
float max_draw = 10*(sqrtf(m_area + 20) - 1);
// Step 1a - compute the base formulas
float p2_component = 20.0f + 7.0f * sqrtf(m_area + 10);
float p4_component = 50.0f + 22.0f * sqrtf(sqrtf(m_area + 2));
// Step 2 - At really short distances, popping is more annoying even if
// the object is small, so we limit how small the distance can be
if (max_draw < 100)
max_draw = 40 + (max_draw * 0.6);
// Step 1b - combine them
float p4_ratio = p4_component;
if (p4_component < 210.0f)
p4_ratio = p4_component / 220.0f;
else if (p4_component < 230.0f) // Smooth the transition
p4_ratio = (105.0f + p4_component * 0.5f) / 220.0f;
else
p4_ratio = 1.0f;
// Step 3 - If the draw distance is too big we artificially reduce it
// The formulas are still experimental and improvable.
if(max_draw > 250)
max_draw = 230 + (max_draw * 0.08);
// This effecte is cumulative
if (max_draw > 500)
max_draw = 200 + (max_draw * 0.6);
float max_draw = p4_ratio * p4_component + (1.0f - p4_ratio) * p2_component;
float max_quality_switch_dist = 90;
// Step 4 - Distance multiplier based on the user's input
// Step 2 - Distance multiplier based on the user's input
float aggressivity = 1.0;
if( UserConfigParams::m_geometry_level == 2) aggressivity = 0.8; // 2 in the params is the lowest setting
else if(UserConfigParams::m_geometry_level == 1) aggressivity = 1.1;
else if(UserConfigParams::m_geometry_level == 0) aggressivity = 1.5;
else if(UserConfigParams::m_geometry_level == 3) aggressivity = 2.0;
else if(UserConfigParams::m_geometry_level == 4) aggressivity = 2.7;
else if(UserConfigParams::m_geometry_level == 5) aggressivity = 3.6;
if( UserConfigParams::m_geometry_level == 2) aggressivity = 1.0; // 2 in the params is the lowest setting
else if(UserConfigParams::m_geometry_level == 1) aggressivity = 1.4;
else if(UserConfigParams::m_geometry_level == 0) aggressivity = 1.95;
else if(UserConfigParams::m_geometry_level == 3) aggressivity = 2.7;
else if(UserConfigParams::m_geometry_level == 4) aggressivity = 3.75;
else if(UserConfigParams::m_geometry_level == 5) aggressivity = 5.25;
max_draw *= aggressivity;
// Step 5 - As it is faster to compute the squared distance than distance, at runtime
// Step 3 - As it is faster to compute the squared distance than distance, at runtime
// we compare the distance saved in the LoD node with the square of the distance
// between the camera and the object. Therefore, we apply squaring here.
max_draw *= max_draw;
@ -245,7 +244,7 @@ void LODNode::autoComputeLevel(float scale)
for(unsigned i = 0; i < m_detail.size(); i++)
{
// Step 6 - Then we recompute the level of detail culling distance
// Step 4 - Then we recompute the level of detail culling distance
// If there are N levels of detail, the transition distance
// between each level is currently each SQRT(1/N)th of the max
// display distance
@ -253,7 +252,7 @@ void LODNode::autoComputeLevel(float scale)
m_detail[i] = ((step / biais) * (i + 1));
biais--;
// Step 7 - If a high-level of detail would only be triggered from too close,
// Step 5 - If a high-level of detail would only be triggered from too close,
// and there are lower levels available, skip it completely.
// It's better to display a low level than to have the high-level pop
// suddenly when already quite close.