NX 10 - rendering a car

[Ritchie]

Hello fellow NX users,

I have heard a lot about the new rendering module in NX 10, especially the new raytraced studio. Having just migrated from 8.5, this really looks like a big enhancement. Having worked with 3DMax in the past to render projects once they were completely finished (because of the painstaking export import process) I'm very keen to try the new rendering possibilities in NX.

I have made a few first renderings using raytraced studio of a car that I have designed and co-developed, called the RoadKart. Here is a link to some of the results:

http://www.mobitecture.com/portfolio/roadkart/

First impressions: NOT BAD! I did have to up the colors in Gimp to add more contrast but I'm quite impressed with the textures. Just look at that carbon! Also some of the details come out really nicely, like the headlights. These are elements that usually take a lot of time to get it right, this is really not bad for a first draft.

Untill now I have mainly worked on the materials, the scene itself is out of the box. I just added one light and selected a setting. I have fiddled a little with the lighting, but I haven't really noticed any big difference. Knowing that there are several rendering modes in NX, I would like to know what is the best way to control the lighting in Ray Traced Studio. I know that there are predefined scenes, but as far as I can tell they only influence the True Shading display? Since the documentation is rather limited on the rendering module I'm hoping to learn from the "best practice"" that some of you might have...If not then let's use this thread to define one! =)

On thing I have noticed is that the floor plane is not being rendered correctly. I have modified its offset in the Scene Settings so that it crosses through the bottom part of the tires, just a few centimeters to "ground" the car. In the current renderings this effect is not visible. I have no idea why, maybe the rendering module does not like intersecting geometry?

Any comments, critics and tips are very welcome!

 

[Toost]

Nice Work !

The quickest way to a pretty good image is to use one of the prepackaged scenes. They all(?) use HDRI lighting, which means that the light set-up is pre-done. You can then swap the lighting image and or add extra lights to the scene.
The trick is the scene editor, that's where all the magic is done.

Regarding the shadows on the floor plane / under the model, - It seems that these shadows are very difficult to render realistic, i see quite a few rendered models ( from all systems ) which are brilliant, but this particular shadow where the wheels make contact is poor / not realistic.
Make sure that Ambient shadows are "on" and that you use the "Full render" option.


Regards,
Tomas

 

[jpetach]

Ritchie,

NX 10 added an option for "Use with Ray Traced Image-Based Lighting" to "Scene Editor - Lights". In NX 10 the default is that the option is unchecked / off. But for lights defined before NX 10 the light(s) will have the behavior enabled. You may find the the light(s) (especially "Scene Top") from legacy parts need to be edited to turn this off in NX 10. Turning this off should improve the realism of the shadows.

HTH,
Joe

 

[Ritchie]

OK thanks guys, I just added some more images to test a few things. I have removed the carbon fibre material temporarily to speed up the rendering process while I'm looking for the right settings. These last four images are unedited and I think the colours look much better and there is more contrast as well.

I have modeled a physical floor underneath the car and I think this is a big improvement. I just could not get this result with the environment floor plane so I disabled it.

I have also switched of the option Joe suggested (this changed a lot!), set the shadows to high contrast and upped the gamma setting. The last two images are without any light with the option "use with ray traced image based lighting, the two before are with the scene top light with this option enabled. The scene top light is the only active light in the scene. Overall it looks nice, although I have no idea where the strange reflection above the rear wheel comes from...

I guess I'll be looking into the scene editor a bit more to experiment with some of the settings. Tips and critics are welcome in the meantime!

 

[Dave K]

The new rendering tools look pretty good, I've wanted to try them again, but have not had the opportunity. I did this one back in 2008 or 2009, and since then read about new tools to make a lot of it easier.

http://www.plm.automation.siemens.com/en_us/Images/RileyTech_DP_Front_Lights_tcm1023-107909.jpg

I never could get the OOTB floor plane to look right, so I modeled the ground too.

Looks good Ritchie!

-Dave

NX 9, Teamcenter 10

 

[Ritchie]

Cool Dave! Did you use a real lightsource for the headlights?

 

[Dave K]

yeah, I set 4 lights for headlights, one red interior light, and 4 tail/brake lights. Render time was about 16 hours with the lights on, as I recall. Hardware has come along some since then too, lol.

-Dave

NX 9, Teamcenter 10