VIZGROUP
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Static /Dynamic
The viz_group is used to control elements of the scene that we want to display or not rendering and/ or in the openGL. It ranks scene elements !
- When you create viz_group, you have to separate the environment that will remain static, and it will be render once, from dynamic elements in motion which will be render on each frame as the character.
- We create a viz_static and a viz_dynamic, where we associates each elements we desire, then the viz_render will bring together these two viz_group called sub_vizgroups in the shading group.
Shading Group
The shading group enable to associates a material to a geometry for each viz_group.
The shading group is created in a modeling software, in this case here it’s maya :
Adjustment in Relight:
Sub Vizgroup
The sub_vizgroup enable to call a viz_group with these geometry and materials already linked. The advantage is that if some materials of the scene are replaced, every viz_group will be affected. , so no need to relink all the materials. We can disable materials so that the geometry does not appear on the rendering or assign him another material. We recongnize the sub_vizgroup by these brackets.
GEOMETRIE
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The geometry is an object imported from the scene in .gop, always put the type SUBDIV, leaving it in MESH the geometry will not be smooth to the render.
Sub Texture
Allows smooth texture, to not have any trouble with the chamfers of the object.
MATERIALS
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Diffuse / Spec / Reflection / Transparency
- Diffuse : Where we bind (ctrl + B) the texture
- Specular : adjustment of hue or the intensity and if we want it sharp or diffuse.
- Réflection : intensity of the reflection.
- Transparency : Manages the transparency of the object, and do not forget when shadows are raytrace the rt-transparent-layers is activ, so it can manages the transparency.
Fresnel
The fresnel is the amount of diffused light reflected in relation with the position of the light source. Areas which are tangents to the light become brighter.
GI Bounce / GI Gather
- GI Bounce Increase the diffuse of the GI around the object.
- GI Gather : increase the diffuse of the GI on the object.
PICTURES
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Antialiasing
Determines how to filter texture images, use EWA for a better quality.
Force_mipmap_level
The higher the number is high quality will be diminished and the computation time faster.
Light set
We use the light set to enlighten the choosen viz_group with the lights of our choice.
Global Illumination -GI-
Global Illumination uses direct illumination, which comes from a luminous source, and the indirect illumination which is the mixing of the reflective colour of the scene, thereby the shades are mixed with the colour and so they are stained.
Réflexion
Reflection of light on the object which re-balance light waves.
Ambiant occlusion
Create / Shadop / Ambiant_Occlusion_Ptc We then bind on the ambient intensity.
Shadows
Differents shadows:
Algorithm :
- Raytrace : No need for precalculation, but the calculation time is longer than a shadow map.
- Shadow map : The calculation is fast but the shadows are sharp.
- Soft shadow map : It’s fast to calculate this shadow, and we can use the light radius.
- Deep shadow map : Longer to calculate than a shadow map. We use it for detailed shadows like the fur, the anti-aliasing, the volume and the transparency is considered.
Projection mode :
- Perspective : Uses the direction of the light as a camera to take the map
- Omni : Uses 4 directions (North, East, South, West) to project shadow around the light. Used only for the point.
Blur radius : It’s used to blur evenly the shadows, it doesn’t consider the distance of light, like the light radius. It can be used with all the algorithm.
Light radius : The light radius blur the shadow but taking account the distance of the light, to a closer realism. Shadow will be sharp near the object and more and more blured with the distance. It’s only used with the raytrace and the soft shadow map.
Difference light_radius and light_blur :
Bias : To avoid shadow artifacts against the object, it allows to shift the shadow, do not put a too high figure otherwise the shadow is off hook from the object.
Rendered only with the direct lights :
Rendered with the reflection :
Rendered with the GI :
PTC
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The "Point Cloud’’ is generated by a geometries group (vizgroup). Called PTC, it’s used by many shaders (occlusion, GI, reflection...)
Static /Dynamic
During the creation of the scene, we separate the static and the dynamic to render only inanimate object, saving time and memory. So the path where the PTC is stored will change :
- Static : .ptc
- Dynamic :${c}.ptc (will allow increment)
Viz group
Allow to choose the geometry that we want to calculate for the shader.
Opacity PTC
Gives transparency to PTC which used the occlusion, the GI does not take into consideration the opacity.
Disk radius
Disk radius is the size of PTC. The lower the number more the PTC will be precise but much longer to calculate.
Artifacts created by too big PTC :
Shading bounce
The shading_bounce can increase rebounds between the objects for a closer realism.
