Maxwell Render | Official public forum

Hello all,

I'm about 3 months new to Maxwell and hit my first roadblock. My emitters are always too dim and won't illuminate interiors bright enough.

For example, I am trying to render the inside of an elevator car. The car model is imported from Solidworks into Maxwell Studio where I do all my work. I setup a camera with one wall of the car hidden from the camera so it can show the inside. Four incandescent light bulbs (60-100w each) should illuminate the inside, but my rendering shows up almost pitch black. See an example here: http://img220.imageshack.us/img220/7921/58279741.png

So I played with the camera settings to take in more light and this is what I get: http://img232.imageshack.us/img232/4248/74267258.png

You'll notice a wood panel outside and right of the car in the first picture. I put it there to test the camera settings as basis of comparison. When I tweak the camera to let in more light it gets almost completely washed out.

Where am I going wrong here? Any and all help is appreciated!

-Josh

2 things come to mind:

1) Are you modeling to real-world scale?
2) What is the EV that you camera settings give?

Also I think I remember a bug where rendering into a closed room like that with a wall hidden to camera resulted in dark renderings -- let me see if I can find it...

Best,
Jason.

One thought. You might try checking the scale (it looks like the light isn't traveling very far which suggests to me that maybe it's coming in at some very large scale). There's no easy way to dimension objects in studio. I usually just bring in a 1x1 plane which will give you a 1mx1m plane. That should at least give you an idea if you're in the neighborhood in terms of scale.

-Brodie

What is lighting up the wood on the outside, btw? skydome?

-Brodie

For checking scale in Studio just switch to a orthographic camera view (F,B,L,R,T,D) and turn the grid on -- if you like you can specify the grid units in the preferences.

Best,
Jason.

Yeah, here's the bug I was talking about -- take a look and see if it is a similar issue:

http://www.maxwellrender.com/forum/view ... 12#p335012

Best,
Jason.

1) Sorry to say that I'm ignorant about scale in Studio. I do know that the scale was correct while modeled in Solidworks. Does it always import at the same scale? Oh and how do I turn the grid on?

2) The first picture has an EV of 13 and the second is 8. The environment is Physical Sky.

Let me know if you have any other questions...........

At the top of the Viewport you'll see a dropdown called "Display" -- just put a check next to "Grid"... I would make this change in the perspective "camera" instead of your actual cameras. Alternately you could set up an new camera to keep in orthographic mode for manipulation purposes... I often have several orthographic modes going at the same time.

The possibility to have multiple viewports open of the same scene with different viewpoints is one of the many advantages Studio has over Sketchup.

An EV of 8 would be typical of an indoor scene like you have here -- here's a list of EV settings:
http://en.wikipedia.org/wiki/Exposure_value

Also I'm not sure if you intend the wood to be on the interior of the room -- but if you do it looks like you may have to create UV's for the texture(s) to be mapped on those walls.

Also set the environment to "none" since there is no reason to have the physical sky on and it's causing light to penetrate into the room.

Best,
Jason.

Ya, sounds like it's working properly then. An EV of 8 would be way overexposed for an exterior scene (hence the wood is bleached out), but would be about right for an interior.

Likewise an EV of 13 would be ok for an exterior but very underexposed for an interior.

I did a quick test and couldn't reproduce the bug that thread talked about. Perhaps it was fixed in the last update?

-Brodie

I never had time to test it when it came up and I don't know how or if it was resolved... but the problem in this thread is clearly about camera exposure values.

Definitely read that link I posted about EV as that will hopefully set you on the right path to understanding what's going on KMC.

Best,
Jason

It sounds like it might be the sunlight with emitters issue, where the engine gives preference to the high powered sunlight. If it's not a scale problem, then I would think that disabling the sun would solve the problem.

Thanks to all of those who replied. I really appreciate the help! Let me spend some time experimenting with your advice and I'll get back with the results.

Just a guess based on some problems I've had:

1. Adjust your ISO film so it's more sensitive to light,
2. Adjuster the shutter aperture to regulate the amount of light,
3. Adjust the intensity,
4. Change your light globes to higher wattage or a different type of light output.
5. Add multilight and position some lights out of view that illuminate the car interior, (maybe look at setting these so they don't cast shadows?)

I think I have a better understanding of cameras and lighting thanks to everyone on here. However, I discovered a brand new issue while working on a new project. Take a look;

http://img232.imageshack.us/img232/4961/331838sl2.png

I might just be nitpicking, but I'm not happy with the quality of the rear "wall wash" light. Basically that's a light that shines down to highlight the surface of the wall. You can see this effect on the top of the rear middle wall. For some reason that area is still fuzzy while the rest of the car is clean and finished.

The SL is currently at 18.38 and that area hasn't improved much since the rendering began. Do I just have to keep rendering more or am I doing something else wrong?

Thanks again in advance!

what's your current lighting setup. what sort of emitters do you have, how many, where are they, do you have an hdr lighting the scene as well, skydome, none?

-Brodie