Day 4

Daily Report : 11th July 2013

Lesson 7 :

I am glad that now I have a better understanding of the copy stamping node.­

In lesson 7, I learn on how to copy attributes I create in the copy node and apply it to my geo for examples attributes like color.

By using the point on the grid, i can apply a geo to each point on the grid I can also apply random geo to be on each point by using the stamp function

stamp(where the attribute node is, name of the attribute, float value)

Camera handles
first handle is the look at handle

second handle is the eye view

The camera handles are really new to me and im really glad i came across this.
This will definitely help me in the long run when i need to render depth of field.

One thing houdini has an advantages is that I can interactively move the depth of field whereas maya i have to manually type values and keep rendering to see results.

right clicking to get more option like focus angle, frustum handle

under the camera parameters, in the sampling tab, I can adjust the focus distance and f stop

the frustum handle control the near and far clipping. (it is use to control how much area you want to render)

the switcher camera node is really useful camera, with this i am able to render multiple shots in one scene and do not have to separate the render.

Mantra will create micro polygon renderer (scanline renderer)

pbr is a global illumination render

something new that i never learned before is that I can actually have a parent child relationship and control which mantra you want to render.

Stereo camera

zero parallax settings :

where the screen you want the image to be sitting.

interaxial distance:

separation between 2 eyes.

Lights:

point light points the light to everywhere (pointing lights to all direction)

Spot light and point light are similar, but a spot light has a cone shape to create the light.

cone angle - adjust the angle of the cone light

cone delta - the greater the value, the sharper the line.

cone roll off - intense to shallow

Area light has a line, grid and sphere light type.

line light type is like a florescent tube light.

grid light type is a rectangular area that is emitting light.

disk - circular panel light.

sphere - 3d light. 

The render above is using the area light type grid. Notice point light and area light render is quite similar except that for the area light the chrome ball is reflecting the area light on its surface.
Area light type for line, disk has the similar effect.

under area light options tab

-normalize light intensity to area (takes all light, scale it in and normalize to a certain range.

The rendered image below is using a distance point light type.

Cleaning shadow noise
under light, shading quality value : the lesser the value, the lesser noise when render.
increase pixel samples
increase noise ­­

Lesson 8 : UV and materials
shortcut keys
spacebar + 5 goes to on viewport to view uv
spacebar + n will make a viewport active
 .rat is a random access texture (houdini format)
vfx /animation .rat (highly optimize)
converting image to .rat file by opening houdini command tool and drag and drop the image i wanted to convert. It will ask for 2 argument, first is what is the file you want to convert and second is what format you want to convert the file to.
 uvproject
unwrapping uv
 uvpelt :
shift + L = select all loop edges
click an edge and press f, to select edges forward
uvbrush is used to relax the uv
if i right click, I can have more options to smooth drag and erase the changes I made to the uv.

**Something learn from Boon Eng:
Under edit, color settings, increase the gamma value and tick all the options below. This is for linear workflow.
It makes your rendered image wash off, but later in compositing, its easier to adjust and tweak the color correction etc.
Regarding the report yesterday about the expression $TX-point("../upvector",1,"P",0)

**Joel has already already explained what the expression means. Its just taking two point node and subtracting from each other.

The guys had been really helpful and patient :)