3114 Posts
Mecabricks Add-on for Blender

About this thread
You will find in this section everything needed to easily make photorealistic renderings of Mecabricks models with Blender.

Software and files needed
Blender Add-on by Mecabricks
• Environment images [e.g. zbyg Packs]
20 Jun 2015, 23:20
Edited 12 Jun 2017, 06:16
3114 Posts
Change Log

See product description page for change log.
21 Jun 2015, 03:30
Edited 12 Jun 2017, 06:16
61 Posts
That look awesome but my computer crash everytime i do a render of my biggest creation.
The render will run for about 30 mins and crash.
I have a pretty good i7 and 8go of ram, my pc should not be a problem...
That pretty annoying, i never had the same problem with POVray or Luxrender

Also, can you add other light with the HDR image ? I switch to Mecabrick and blender because i wanted more flexibility. I'm a complete Blender noob i only use modo a few years back and i'm really lost in Blender interface.
21 Jun 2015, 22:45
3114 Posts

Yes, Blender is not the easiest to understand at first. There are lots of shortcuts to learn!

Do you use Blender 2.74?

Can you try to run it with Open Shading Language checkbox unticked? - It is located a couple of lines under the Render button.
If you want to render faster for testing purposes, you can try to decrease the number of render samples in the Sampling section to something like 100.

Can you also try with smaller dimensions (either by changing X and Y and simply by turning down the percentage scale number).

What kind of graphic card do you have? Is it a NVidia CUDA capable?

Yes you can also add as many lights as you want even with a HDR lighting. Add button (or Shift+A) and choose type of lamp.
You can also attach/mix an emission shader to a mesh. Create a new material and select Emission.

You can also only render part of the image. In the camera viewport, press Ctrl+B and select the area of the camera you want to render. (Ctrl+Alt+B to cancel).

Let me know how it goes.
21 Jun 2015, 23:14
Edited 21 Jun 2015, 23:15
272 Posts
22 Jun 2015, 06:47
Edited 22 Jun 2015, 06:49
61 Posts
Thank you for your advice !

The render did not crash when I unticked "Open Shading language" but I can't show it because I've stupidly close the Blender console and the whole software close with it.

So yeah, my experience with Blender is not great so far, but I've made some progress !

My render had some problem, the image was a little grey, and grainy.
I tried to add a sunlight but apparently that did not work.
How do I add a little bit of gain on the HDR image ? It's pretty easy to do while rendering in Luxrender but I didn't find the big "Add intensity to the light" button in Blender.

For the grain on the picture, I think it's because the samples were to low. The samples for my render were set to 1200. How many do I need in average to have a clear smooth render ?

I have a GTX970 graphic card, so it's more than enough to handle my model.

Thanks in advance for your help !
22 Jun 2015, 14:46
3114 Posts

The reason why I asked for the graphic card is that there is an option to tick in Blender to use the GPU instead of the CPU for rendering. It is much faster but doesn't work with all types of shaders. I think yours shall be compatible.

OSL shaders only run on CPU. I use it for the shader rounding the edges. If it is unticked, you won't get them but the rest shall be fine. It is weird that it crashes after a bit... Did you try to set the dimensions maybe to 25% to see if you can render a smaller complete image before it crashes?

To increase the intensity of the lighting provided by the HDR image, simply increase the strenght - currently set to 1.000.
In the video tutorial, go the sequence where I explain how to open the HDR image. This is the node called Background between Environment Texture and World Output.

This is a challenge to reduce the noise! I tried to set the settings so that it limits the number of samples. It really depends on your image - I generally use something between 800 and 1000. I noticed that with my settings, clear materials are more noisy than dark ones but generally still acceptable. It also depends on the quality of the HDR image you use.
- I set the transparent materials so that caustics can be disabled.
- I clamped the samples
- I enabled Multiple Importance for the environment map.
- etc

It can still be tweaked though.

The easiest is to increase the number of samples but it will increase the render time proportionally.
22 Jun 2015, 20:47
Edited 22 Jun 2015, 23:01
61 Posts
Thanks again for your help !

I didn't have any crash today, with a render at 25% ( http://i.imgur.com/ecPsQdL.png ) and one at 720p ( http://i.imgur.com/DFSgEol.png ).
Now that i think about it, my crash probably happen when i was trying to watch a youtube vidéo on my second screen.

Anyway, thank you for your help, i can't way to start building more !
I'm still a bit unhappy with the noise but i have some idea on how to get rid of it, I'll update if I find a good and easy solution !
22 Jun 2015, 22:36
Edited 22 Jun 2015, 22:37
3114 Posts
No worries

I can see the noise mainly on the white wall of the house. If you find a solution for it, don't hesitate to share.

P.S. You should release the model you used for your test. It looks awesome on the rendering!
22 Jun 2015, 22:56
Edited 22 Jun 2015, 22:59
61 Posts
I will release the model as soon as i finish it. I'm not quite happy with it, some area are still too empty.

For the noise, i was thinking of rendering the white part with super high sample but i also have a few idea with photoshop.
I also want to try to export the model on Luxrender and see how it goes. I'll update when i'll have something interesting !
22 Jun 2015, 23:09
4 Posts
I’m having a similar problem as SaitoGray the computer is a MAC and does not have a graphic card just a chip set on the mother board. When I hit render or chance window view to render it crashes at the first tile. I have reduced Resolution to 25% and samples to 100 without change. The only thing that works is not checking OSL. I have my own template that uses the OSL for its “bevel shader”. Also if I click the material button to look at the objects color setting it crashes. Any ideas?

In studying you script on color i not the hex do not match the RGB setting found in the db.lif file. Where did you get the color data?
23 Jun 2015, 17:50
3114 Posts

I develop on a mac too so I don't think that the issue is here.
It looks different than SaitoGray as he could actually start the rendering.
There is something that your CPU doesn't like somewhere in the scene. It is even more interesting when you say that you can use OSL for other applications with the bevel shader.

Can you confirm that the version of the bevel shader script you use is exactly the same as in the template, lines for lines? It would be very useful to know that.
23 Jun 2015, 20:35
4 Posts
I started to look into my crash problem with OSL checked. The script that works for me comes from the same tread you noted in you tutorial but the first post by VarkenVarken on 05-mar-14 (first page). Your script is found on pager 5 by Piotr 26-May-14. He also has an early post on 06-Mar-14. Both crash my blender. It will take me some time to understand the scripts. My OS is MAC OS X 10.6.8, Python Interpreter is 2.6.1, Blender is 2.74. My next step is to replace Piotr script with VarkenVarken’s. This will take me time.
24 Jun 2015, 15:14
200 Posts
I had to watch the video 4 times to do it, but i got my first render done! Thanks for the great work scrubs!
24 Jun 2015, 15:39
3114 Posts
@OLDNUT I have the latest version of Yosemite on my iMac. I chose the most advanced/fastest version to include in my nodes but I'm not skilled enough to write or modify this bit of code myself. Hope you will find something that works for you

@UmbraManis I jut saw your rendering. Looks good! We can just see that you added the background later because of the thin white edge around the minifig. Is it the first time you used Blender?
24 Jun 2015, 20:57
200 Posts
It is my first time using Blender. I did the background with GIMP.
24 Jun 2015, 21:22
3114 Posts
Well, It's pretty good. Blender is normally quite hard to understand when you open it the first time. Template seems to be not too bad even for new Blender users with a bit of work.
24 Jun 2015, 22:21
Edited 30 Jun 2015, 02:31
3114 Posts
Did you delete the background of the rendered image in GIMP, or did you render the image in Blender with a transparent background?
24 Jun 2015, 23:21
54 Posts
Had the same issue as SatioGray, but unchecked the Open Shading box and rendered my first model! (Zaptor, built by Scrubs, here --> http://www.mecabricks.com/en/models/L0Qa3MWjMol#nbz1qD ) It was my first time using Blender, and I really enjoyed it! Thank you for the great video and template, Scrubs!
25 Jun 2015, 13:27
200 Posts
I removed the rendered background in GIMP.

My renders all seem to be in kind of dim light. Is there an easy way to change that?
25 Jun 2015, 14:00
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