Commit Graph

5 Commits

Author SHA1 Message Date
Lukas Toenne
9e3fa15d4b Added a bunch of additional particle state attributes to the Cycles particle info node:
* Location: Basically the same as the location from Object Info node for object instances on particles, but in principle there could be additional offsets for dupli objects, so included for completeness.
* Size: Single float scale of the particle. Also directly translates to object scale for current dupli objects, but handy to have as a single float to start with instead of a scale vector (currently not even exposed in Object Info).
* Rotation: This is a quaternion, which are not yet supported by Cycles nodes. The float4 is copied to internal Cycles data and stored in the particles texture data, but the node doesn't have a socket for it yet and the data is not yet written to the stack. Code is just commented out so could be enabled quickly if/when rotation support is added to cycles.
* Velocity: Linear velocity vector of particles.
* Angular Velocity: Angular velocity around principle axes.

The texture data is currently packed tightly into the particles texture, which saves a few bytes, but requires an additional texture lookup for some vector attributes which spread over two float4s. Could also add another float4 to particle size to avoid this.
2012-08-31 19:38:59 +00:00
Lukas Toenne
fec872ef9c Added a particle index output to the Particle Info Cycles node. This is required to get consistent ID numbers for particles. The Object ID is not usable since it's a user defined value of the instanced object, which does not vary per instance. Also the random value from the object info node is not consistent over time, since it only depends on the index in the dupli list (so each emitted or dying particle shifts the value).
The particle index is always the same for a specific particle. Randomized values can be generated from this with the use of a noise texture.
2012-07-26 11:40:58 +00:00
Lukas Toenne
5e1bbde01d Particle Info node for Cycles. This can be used to access particle information in material shaders for dupli objects. For now only the particle Age and individual Lifetime (in frames) are supported, more attributes can be added when needed.
The particle data is stored in a separate texture if any of the dupli objects uses particle info nodes in shaders. To map dupli objects onto particles the store an additional particle_index value, which is different from the simple dupli object index (only visible particles, also works for particle dupli groups mode).

Some simple use cases on the code.blender.org blog:
http://code.blender.org/index.php/2012/05/particle-info-node/
2012-06-08 16:17:57 +00:00
Brecht Van Lommel
c3e1fce775 Cycles: add Object Info node, with outputs object location, object/material
pass index, and a random number unique to the instance of the object.

This can be useful to give some variation to a single material assigned to
multiple instances, either manually controlled through the object index, based
on the object location, or randomized for each instance. 

http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Object_Info
2012-05-21 12:52:28 +00:00
Ton Roosendaal
da376e0237 Cycles render engine, initial commit. This is the engine itself, blender modifications and build instructions will follow later.
Cycles uses code from some great open source projects, many thanks them:

* BVH building and traversal code from NVidia's "Understanding the Efficiency of Ray Traversal on GPUs":
http://code.google.com/p/understanding-the-efficiency-of-ray-traversal-on-gpus/
* Open Shading Language for a large part of the shading system:
http://code.google.com/p/openshadinglanguage/
* Blender for procedural textures and a few other nodes.
* Approximate Catmull Clark subdivision from NVidia Mesh tools:
http://code.google.com/p/nvidia-mesh-tools/
* Sobol direction vectors from:
http://web.maths.unsw.edu.au/~fkuo/sobol/
* Film response functions from:
http://www.cs.columbia.edu/CAVE/software/softlib/dorf.php
2011-04-27 11:58:34 +00:00