I'm coming with a very old question but I didn't use sketchup anymore for month and it seems I don"t remember how sections cuts are supposed to work.
I want to use a section to render my kitchen with a better view point.
So I cut a wall and I'm surprised that sketchup allows the sun to enter in, as section cut is not supposed to delete existing geometry as Gaieus says here.
And I'm also surprised that irender nxt make the same "mistake".
I'm almost sure I already used this functionnality in the past as expected.
What's my mistake here ?
SketchUp lets all sun light through the Section Plane, but IRender nXt will properly cast shadows from walls and other objects not visible from the section plane.
The light coming in through the section is a great "feature" of IRender nXt. Take a look at this example:
Where the section plane let's us view the interior of the room with better perspective - since the camera is outside of the room - but still light and shadow properly for windows in the room which is sectioned out.
It's exactly what I expect and what I get now.
In fact I discovered it was caused by a color name C_wall, which was considered transparent by iRendernXt.
I don't understand why but I saw that on different colors prefixed by C_ I used when I created new material in Sketchup.
Is it a special prefix for iRender ?
I just tried it and created a material named C_wall and it was fully transparent in SketchUp.
But then I realized that the last material I had worked on was a fully transparent window, and when you click '+' to create a new material it starts with the settings for the material you are pointed to,
When I made a material C_wall with the opacity set properly, it worked as expected.
If you do find a material which is opaque in SketchUp and transparent in IRender nXt, try to send us a model at support AT renderplus.com so we can take a look at it.
That could be the case for me as well. I'll check that and let you know.