Friday, 17 June 2016

Importing from Sketchup to Unity

Architectural models from Sketchup have been working straight away when they get to Unity. There is no need to convert them to an intermediate format, the .skp files are good enough. I have this linkedin post (also got a pdf) on importing via .fbx that I didn't try yet cause it wasn't necessary.
Questions to investigate:

  1. tried importing in skp format from current Sketchup (June2016) version and it doesn't work, but when trying from older version it works.
  2. we need the Pro version to export to .fbx
  3. is it better to use fbx or skp?

Tuesday, 5 April 2016

Pipeline modelo com Oculus - desactualizado com a versão 5.

Tenho um Doc word chamado "Pipeline_Unity_OculusRift.docx". Abaixo está uma versão sem imagens.

Geração de modelos básicos para Oculus Rift em Unity
Descrição – permitir navegação com Oculus Rift em geometrias importadas de programas de modelação 3D (Sketchup, Blender, Rhino, 3DsMax, etc.).

Configuração do Unity para Realidade Virtual

Settings Globais
Ir ao menu Edit\Project Settings\Player e activar Virtual Reality Supported no Inspector (lado direito).

Importar Assets do Oculus Rift para Unity

Descarregar package “OculusUtilities” do site do Oculus Rift: Developer/Downloads/Engine Integration. Verificar compatibilidade com a versão do Unity que estamos a usar. Se necessário actualizar o Unity.
Unzip do ficheiro e arrastar o package para os Assets ou ir a Assets/Import Package/Custom Package. Aceitar a importação de todas as partes do pacote.
Nos Assets, abrir a pasta OVR/Prefabs e arrastar o OVRPlayer para a Scene. Depois pode-se afinar a posição do player em relação ao modelo.

Modelo 3D: importar e modificar

1 – Importar modelo 3D. Modelo tem de estar em formato aceite pelo Unity. Para importar basta arrastar ficheiro para os Assets. É boa ideia organizar os Assets em pastas. Verificar se geometria está correcta, materiais em texturas sobreviveram à importação, etc.
2 – Arrastar modelo para a cena, clicar e pôr o seu centro nas coordenadas 0,0,0. Se os modelos estão em coordenadas muito longe do centro (milhares de metros) podemos ter problemas.
3 – Expandir modelo na Hierarquia (lado esq.), seleccionar todas as peças do modelo e seleccionar Add Component no Inspector (lado direito): Physics->Mesh Colider. Isto faz com que todos os polígonos passem a ser impenetráveis para o avatar (é um pouco dispendioso mas é o mais simples).


Carregar Play e navegar, com ou sem Oculus.

Tuesday, 15 March 2016

Learning Resources on Computational GRaphics

3Ds MAx on Lynda.com

After taking the first course, which I did not finish since I ain't interested in animationa and advanced lighting, etc. I signed up for a trial account at digital tutors, which is also prety good. The videos I watched from this short course, CG101 are prety good and explains very well the concepts.

So now I need to learn 3DS or other 3D modeling sftware to be able to manipulate the Salamonde model from Autocad 3D. So I'm taking this course 3ds Max 2013 Essential Training and hope that 2013 is not so far away from 2016.


Some more sites on CG

http://www.scratchapixel.com/lessons/3d-basic-rendering/global-illumination-path-tracing

http://home.lagoa.com/2014/04/ray-tracing-vs-path-tracing-in-plain-english/

Monday, 14 March 2016

Materials

There are 2 kinds (at least for now)

  • Physical materials govern colisions: rebound, friction, etc.
  • Visual (?) materials govern the interaction with light (that's a very correct way of putting it). They call this Materials. I'll discuss.
Material (visual) properties:
  • Albedo -  In reality the definition of albedo is the percentage of light it reflects, whiteness - blackness, but here they use it for the color when there is no light (strange...maybe they mean under neutral, white light). Albedo comes from latin albus =  white. We can assign one value to the whole oblect or a map.
  • Metalic (map and slider) - the way it reflects light,
  • Roughness - more on the way it reflects light, see diffuse and specular to know more, later on.
  • And there are more maps which can be stored in the chanels of the rgb+alpha images 
WHat I don't know yet is how the maps are atributed to the geometry!


Sunday, 13 March 2016

Colisions

This video explains the logic well. Must assign colision properties to objects. The easiest way is to assign Mesh coliders, but it is expensive since the engine must keep track of all the polygons. Most times we can use box or sphere coliders and set them in a smart way.

Animation

For now I'm not to worried about this but what I learned:
animations are created in Maya or 3Ds or Blender, Unity is not good;
creating a character has three steps: modelling (building the model mesh), rigging (the skeleton and the logic and hierarchy and skinning (joininng the two);

Friday, 11 March 2016

Lighmaps UV

This expression keeps popping up from time to time, had to investigate.

So lighmapping is a way of baking light effect in objects. It only works for static objects and static lights. As is is baked it is not calculated in realtime. In reality a new texture incorporating the effect of lighning replaces the material's native texture and the light can be eliminated (or at least we don't need to calculate it's effect on that object in real time). Great video here.

Wikipedia page

Light in general in Unity

Lighmaps in Unity (starting point)

Now another question that I didnt understand is this UV mapping, though I think I have an idea that this is similar to the way FLAC2D from Itasca works, with local coordinates.

So this answer is great.

UV are the local coordinates of a flat surface with U and V going from 0 to 1. This video explains well what and how a UV map is built, but it really is the "skin" of the object taken out, cut in strategic places and stretched out and mapped in the coordinates.