Further work on ParticleFlowRenderer, now correctly rendering the demo flow field.

modules/vectorfield/glsl/particleflowrenderer.vert

@@ -63,6 +63,7 @@ uniform mat4 _projectionMatrix = mat4(
 uniform float _time;
 uniform float _frameLength;
 uniform float _lifetime;
+uniform float _scale;
 
 uniform sampler3D _volume;
 uniform TextureParameters3D _volumeTextureParams;
@@ -71,19 +72,19 @@ uniform TextureParameters3D _volumeTextureParams;
 subroutine (RenderPassType)
 void update() {
     if (_time > in_StartTime) {
-        float age = in_StartTime - _time;
-        if (age > _lifetime) {
+        float age = _time - in_StartTime;
+        if (age > _lifetime || length(in_Velocity) < 10.0) {
             // particle expired, recycle
             ex_Position = in_InitialPosition;
-            ex_Velocity = texture(_volume, (_volumeTextureParams._worldToTextureMatrix * vec4(ex_Position, 1.0)).xyz).xyz;
+            ex_Velocity = texture(_volume, (ex_Position / _volumeTextureParams._size).xyz).xyz;
             ex_StartTime = _time;
         }
         else {
             // particle alive, advance
-            ex_Position = in_Position + (in_Velocity * _frameLength * 0.1);
+            ex_Position = in_Position + (in_Velocity * _frameLength * 0.05 * _scale);
 
             // compute new velocity by mixture of old velocity and flow at current location, model some inertia
-            vec3 v = texture(_volume, (_volumeTextureParams._worldToTextureMatrix * vec4(ex_Position, 1.0)).xyz).xyz;
+            vec3 v = texture(_volume, (ex_Position / _volumeTextureParams._size).xyz).xyz;
             ex_Velocity = mix(in_Velocity, v, 0.5);//smoothstep(0.5, 2.0, v/in_Velocity));
             ex_StartTime = in_StartTime;
         }
@@ -99,7 +100,7 @@ void update() {
 subroutine (RenderPassType)
 void render() {
     float age = _time - in_StartTime;
-    ex_Transparency = 1.0;// - (age / _lifetime);
+    ex_Transparency = (age >= 0.0) ? 1.0 - (age / _lifetime) : 0.0;
 
     gl_Position = _projectionMatrix * (_viewMatrix * (_modelMatrix * vec4(in_Position, 1.0)));
     //ex_Position = in_Position;

modules/vectorfield/processors/particleflowrenderer.cpp

@@ -84,7 +84,7 @@ namespace campvis {
         addProperty(p_lenThresholdMax);
         addProperty(p_camera);
         addProperty(p_sliceNumber);
-        addProperty(p_Time);
+        addProperty(p_Time, INVALID_RESULT | FIRST_FREE_TO_USE_INVALIDATION_LEVEL);
         addProperty(p_flowProfile1);
         addProperty(p_flowProfile2);
         addProperty(p_flowProfile3);
@@ -156,15 +156,14 @@ namespace campvis {
                 glEnable(GL_DEPTH_TEST);
                 _shader->activate();
 
-                _shader->setIgnoreUniformLocationError(true);
-                _shader->setUniform("_viewportSizeRCP", 1.f / tgt::vec2(getEffectiveViewportSize()));
                 _shader->setUniform("_projectionMatrix", cam.getProjectionMatrix());
                 _shader->setUniform("_viewMatrix", cam.getViewMatrix());
+                _shader->setUniform("_modelMatrix", vectors->getParent()->getMappingInformation().getVoxelToWorldMatrix());
+                _shader->setUniform("_scale", scale);
 
                 if (p_enableShading.getValue() && light != nullptr) {
                     light->bind(_shader, "_lightSource");
                 }
-                _shader->setIgnoreUniformLocationError(false);
 
                 if (getInvalidationLevel() & FIRST_FREE_TO_USE_INVALIDATION_LEVEL) {
                     // stage 1: perform 1 step of particle simulation
@@ -173,6 +172,8 @@ namespace campvis {
                     _shader->setUniform("_frameLength", frameLength);
                     _shader->setUniform("_lifetime", 10.f);
 
+                    LINFO(_currentTime);
+
                     tgt::TextureUnit flowUnit;
                     vectors->bind(_shader, flowUnit, "_volume", "_volumeTextureParams");
 
@@ -201,7 +202,7 @@ namespace campvis {
 
                 _shader->selectSubroutine(tgt::ShaderObject::VERTEX_SHADER, "render");
                 glBindVertexArray((_drawBuffer == 1) ? _vaoA->getId() : _vaoB->getId());
-                glPointSize(10.f);
+                glPointSize(4.f);
                 //glDrawTransformFeedback(GL_POINTS, _feedback[1-_drawBuffer]);
                 glDrawArrays(GL_POINTS, 0, _numParticles);
                 glPointSize(1.f);
@@ -354,7 +355,7 @@ namespace campvis {
         std::vector<float> startTimes;
 
         tgt::vec3 imageSize = vectors->getSize();
-        _numParticles = 100;
+        _numParticles = 2048;
 
         for (GLuint i = 0; i < _numParticles; ++i) {
             tgt::vec3 position, velocity;
@@ -364,9 +365,9 @@ namespace campvis {
                 velocity.x = vectors->getElementNormalizedLinear(position, 0);
                 velocity.y = vectors->getElementNormalizedLinear(position, 1);
                 velocity.z = vectors->getElementNormalizedLinear(position, 2);
-            } while (velocity == tgt::vec3::zero);
+            } while (tgt::length(velocity) < 100.f);
 
-            float startTime = generateRandomFloat(.1f);
+            float startTime = generateRandomFloat(10.f);
 
             initialPositions.push_back(position);
             initialVelocities.push_back(velocity);