i probably wouldn't go that far with plants, unless they are complex plants

it's more likely just a classic case of stretching, scaling and skewering

you can do all of this with matrix ops, or simply moving the vertices of a quad

note that this will distort the texture!

i imagine that in trine, it's alot more involved than that

some game companies animate plant movement for common plants, since that always gives the best result

however, it should be enough to just modulate the plant vertex positions a little

a basic formula would be:

const float MAX = ...

const float POWER = ...

x = 1.0 - min(MAX, distance(player, plant)) / MAX // get euclidian distance

z = (plant.x - player.x) / MAX // get signed X-distance

vertex.top_left += x * z * POWER

vertex.top_right += x * z * POWER

in a shader, you can easily find the top vertices in one go by multiplying with .t, assuming t == 1 at the top of the texture

like this:

vertex.x += x * z * POWER * texCoord.t;

note that 1D distance is a simple calculation: abs(x1 - x2)

but for it to be signed, lose the abs() and you can tell which side the player is on!

### Show differencesHistory of post edits

### #2Kaptein

Posted 26 December 2012 - 07:10 PM

i probably wouldn't go that far with plants, unless they are complex plants

it's more likely just a classic case of stretching, scaling and skewering

you can do all of this with matrix ops, or simply moving the vertices of a quad

note that this will distort the texture!

i imagine that in trine, it's alot more involved than that

some game companies animate plant movement for common plants, since that always gives the best result

however, it should be enough to just modulate the plant vertex positions a little

a basic formula would be:

const float MAX = ...

const float POWER = ...

x = 1.0 - min(MAX, distance(player, plant)) / MAX // get euclidian distance

z = distance(player.x, plant.x) / MAX // get signed X-distance

vertex.top_left += x * z * POWER

vertex.top_right += x * z * POWER

in a shader, you can easily find the top vertices in one go by multiplying with .t, assuming t == 1 at the top of the texture

like this:

vertex.x += x * z * POWER * texCoord.t;

it's more likely just a classic case of stretching, scaling and skewering

you can do all of this with matrix ops, or simply moving the vertices of a quad

note that this will distort the texture!

i imagine that in trine, it's alot more involved than that

some game companies animate plant movement for common plants, since that always gives the best result

however, it should be enough to just modulate the plant vertex positions a little

a basic formula would be:

const float MAX = ...

const float POWER = ...

x = 1.0 - min(MAX, distance(player, plant)) / MAX // get euclidian distance

z = distance(player.x, plant.x) / MAX // get signed X-distance

vertex.top_left += x * z * POWER

vertex.top_right += x * z * POWER

in a shader, you can easily find the top vertices in one go by multiplying with .t, assuming t == 1 at the top of the texture

like this:

vertex.x += x * z * POWER * texCoord.t;

### #1Kaptein

Posted 26 December 2012 - 07:09 PM

i probably wouldn't go that far with plants, unless they are complex plants<br />it's more likely just a classic case of stretching, scaling and skewering<br />you can do all of this with matrix ops, or simply moving the vertices of a quad<br />note that this will distort the texture!<br /><br />i imagine that in trine, it's alot more involved than that<br />some game companies animate plant movement for common plants, since that always gives the best result<br />however, it should be enough to just modulate the plant vertex positions a little<br /><br />a basic formula would be:<br />const float MAX = ...<br />const float POWER = ...<br /><br />x = 1.0 - min(MAX, distance(player, plant)) / MAX // get euclidian distance<br />z = distance(player.x, plant.x) / MAX // get signed X-distance<br />vertex.top_left += x * z * POWER<br />vertex.top_right += x * z * POWER<br /><br />in a shader, you can easily find the top vertices in one go by multiplying with .t, assuming t == 1 at the top of the texture<br />like this:<br />vertex.x += x * z * POWER * texCoord.t;<br />