Dear friends,
I am sure that some of you have already guessed that the "repaint" check was there for a forthcoming feature. Our next version (v1.1), will include the necessary mechanism for Thea to co-operate with Colimo (a commercial application by Motiva, find out more at the related web page).
In more detail, with next version, it will be possible to select which materials you would like to edit in post process. Additional channels will be calculated for these materials that will allow changing the color and texture of them, after the render finishes, creating infinite variations! The editing takes place in Motiva's Colimo application which, by utilizing the GPU, performs the changes in realtime.
Thea calculates all the extra channels for the repaintable materials during one and single render, with small time penalty (compared to making a single render). This means that you can create many variations of your render, practically without more time spent on rendering! In addition, the exporting and launching of Colimo is completely automated.
Here, you can see a "demonstration" of the new feature. All these images have been created by a single render of Thea! The scene was quite difficult (lots of different sources of lighting) and it took ~12h on a Q6600 (originally rendered at 2048p). This time is fully amortized considering that there were, in this example, 375 combinatorial renders generated in post-process. Using the web export feature of Colimo, all the combinations can be generated based on a predefined list of choices per repaintable material (you can select the material in the first choice box and its texture in the second choice box).
http://www.thearender.com/resources/Col ... eview.html
We believe that this will be a very cool feature and a very "convincing tool" when making design changes.

best wishes
We list here some important aspects regarding Thea Render + Colimo integration, that might provide better understanding of the new feature.
- The extra channels needed are computed during a single render; that is, select your repaintable materials, check the repaint option and hit render. At the end of the render, the whole project can be saved and Colimo launched automatically. Memory restrictions may apply depending on the number of repaintable materials and resolution.
- The calculation of necessary channels is being accomplished by the unbiased modes TR1 and TR2. We decided to integrate the calculations on the modes that give the highest render quality.
- The repaintable materials must at least have one diffuse property. SSS materials cannot be "repainted". Quality of the post process editing and composition is high although small differences may exist compared to re-rendering from scratch with the altered materials.
- Colimo is currently a Windows-only application. Although it uses the GPU, its requirements are not particularly high in that aspect (a DirectX9 compatible graphics card); it will still perform interactively with low end cards, although the more card memory the better (handling more repaintable materials). Saving the image or using the web export feature may take somewhat longer than realtime due to supersampling considerations.
- Colimo is a commercial application being developed and sold by Motiva Infografia, that is the same guys (Victor and Jan) that are also making the 3dsMax plugin (needless to say how closely we are working with).