From c5da28dac21aa5b627a8e4a5a08a003281ebfc99 Mon Sep 17 00:00:00 2001
From: Vanessa Karolek <vaka1997@uni-koblenz.de>
Date: Wed, 26 Jan 2022 19:27:08 +0100
Subject: [PATCH] align particles to face the camera
I used [1] as reference and for understanding :D
[1] http://www.opengl-tutorial.org/intermediate-tutorials/billboards-particles/billboards/
---
projects/wobble_bobble/shaders/particle.vert | 9 ++++++++-
projects/wobble_bobble/src/main.cpp | 8 ++++++--
2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/projects/wobble_bobble/shaders/particle.vert b/projects/wobble_bobble/shaders/particle.vert
index bb864e07..bebf2143 100644
--- a/projects/wobble_bobble/shaders/particle.vert
+++ b/projects/wobble_bobble/shaders/particle.vert
@@ -12,6 +12,10 @@ layout(location = 0) in vec2 vertexPos;
layout(location = 0) out vec2 passPos;
layout(location = 1) out float passMass;
+layout( push_constant ) uniform constants{
+ mat4 mvp;
+};
+
void main() {
vec3 position = particles[gl_InstanceIndex].minimal.position;
float size = particles[gl_InstanceIndex].minimal.size;
@@ -20,5 +24,8 @@ void main() {
passPos = vertexPos;
passMass = mass;
- gl_Position = vec4(position + vec3(vertexPos * size * 2.0f, 0), 1);
+
+ // align particle to face camera
+ gl_Position = mvp * vec4(position, 1); // transform position into projected view space
+ gl_Position.xy += vertexPos * size * 2.0f; // move position directly in view space
}
\ No newline at end of file
diff --git a/projects/wobble_bobble/src/main.cpp b/projects/wobble_bobble/src/main.cpp
index e4000544..a9df5187 100644
--- a/projects/wobble_bobble/src/main.cpp
+++ b/projects/wobble_bobble/src/main.cpp
@@ -384,7 +384,11 @@ int main(int argc, const char **argv) {
timePushConstants.appendDrawcall(static_cast<float>(dt));
cameraManager.update(dt);
-
+
+ glm::mat4 mvp = cameraManager.getActiveCamera().getMVP();
+ vkcv::PushConstants cameraPushConstants (sizeof(glm::mat4));
+ cameraPushConstants.appendDrawcall(mvp);
+
auto cmdStream = core.createCommandStream(vkcv::QueueType::Graphics);
const uint32_t dispatchSizeGrid [3] = { 16, 16, 16 };
@@ -496,7 +500,7 @@ int main(int argc, const char **argv) {
cmdStream,
gfxPass,
gfxPipeline,
- vkcv::PushConstants(0),
+ cameraPushConstants,
drawcalls,
renderTargets,
windowHandle
--
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