Since my last post I have tried to use radiosity to tone down the overly bright renderings - well they aren't overly bright any more - in fact they are very dark. Increasing the 'intensity' of the light source (e.g. putting several '250' watt bulbs) did little to brighten the image. Similarly the lighten option also had little effect.
The ray trace seems to work fine, and resetting the radiosity has no effect. Any help would be appreciated. I would like to be able to have the same light intensity that the viewer shows generally in 3D view. I have the program settings at 3 for moderate. I have attached a screen shot of the options in the renderer section.
Per the request the version is 14.00.C.624
Hi Steve,
First, you will notice at the bottom of the forum is a link to an update. This will bring your version up to the latest (637) and address a couple of issues, although you may not have come accross them. I can't remember now whether the Overcast setting was added in this update or if it was the first update to V12 that added it.
Basic render is essentially your 3D view with some lights and shadows applied and this is fine for exterior renders. Radioisty tries to replicate reality and to do so takes a lot of other factors into accoount. It does have a number of issues but these mainly relate to getting a balance between interior and exterior light.
Probably if you turn off the sun and render just an interior view it may be OK. If you have the sun on and it is coming in through a window, then the volume of light from outside will overpower the 'artificial' lights in the same way as would happen in real life with a camera. Exclude the window from the camera's view and the lens will open and your photo will come out OK. Radiosity in TFP works essentially the same. My personal opinion is that it should not work that way, that interior lights should be about 10 times as bright to even up this discrepancy.
A few factors to check:
Are the Global settings correct? If you have it set to "Use current time for rendering" and you do it at night, then there will be no light from the sun. I always turn that off so I do not get caught.
Is the Time of Day OK? 9-10am I have found is best for exterior views. Before 9am the shadows are too long and it is starting to get dark, while after 11am if starts to get too bright and shadows become smaller but dark.
Basic render is usually fine for exterior as there is nothing for light to bounce off which radiosity relies on.
If rendering interior views, exclude windows from the view if possible or set the sun to Overcast or off altogether. The background will still be light so it will look like daylight through the window.
If you have lots of interior lights you may need to use Level 5 to get them all to work.
See if any of the above helps. If not post the BLD (or email it to me if you prefer) and I will have a look to see if there are other issues. Some of the lights work better than others but try the above first.
Allan
First off thank you for your suggestions - I will be trying them and advise.
As to the basic questions: Yes, time of day is off. I have set it for mid afternoon because I want to see what the light would be in this latitude, and have tried a few different times. Basic render has worked for the outside shots, but this would be an unlit hallway - it has no windows in the view. (Interestingly enough the outdoor light does poke through the open bedroom doors. (See attached .jpg)
I will update the program, but it might be the need to render it at 5. The reflections on the floor are realistic, just dark. As I mentioned in my first post, w/o the radiosity the same scene would be entirely washed out.
I will keep you advised. If I need to send you the plans I would rather email them to you as they are my own design. Thanks again.
Hi Steve,
Having seen what you are trying to render I think all you will probably have to do is turn the sun off and I think you will find the lights will come on. This should not really happen in this situation as you do not have any bright exterior light in the scene but I have a suspicion that will fix the problem.
If it does it will confirm my suspicion of an issue here as the sun should not affect it.
If you have edited any elements them make sure you do a backup of your catalogue before you do the upgrade just in case.
My email is alches(AT)iinet.net.au
Allan
Disabling Daylight (which I assume turns off the sun) seems to have helped- see attached and see if you believe these are the results I should be getting w/ track lights w/ 250 watt metal halide ground flood up bulbs - I think I need to continue to determine which lights to use. I seriously doubt that the hallway would actually be that dark with those types of lights in a 10' ceiling on track lights. In which case I believe the program needs to be tweaked for both the sun issue and the rendering of lighted scenes. I set the settings back to 3 (5 did not alter the situation although after waiting for the radiosity engine to finish, modifying the viewpoint and then raytracing it again was done quickly which is a nice feature and the image was really nice.) I will also rotate the lights to see if the wall splash alters - most of the light are pointed down the hallway for the far end of the overhead track, but the lights immediately above the camera are pointed in the same direction and don't seem to have a significant effect on the nearest walls.
Let me know what you think and if there are any other steps to take. I appreciate your time and comments. I may even have some pictures to post (after my wife makes me paint the walls ;).
Hi Steve,
Disabling the sun would be the reason for the improvement.
What you have is the results more or less that I would suspect with that particular light. All the standard lights in TFP have only one light source - so even though you may have a track with 5 lights on it, they are only fittings and the light source itself is probably just in the middle. This is why you are getting a flood of light at one spot and not much elsewhere.
If you want to simulate the effect of a track light then you can add the additional light sources to the fitting and position the sources appropriately along the track. This is not easy, unless you are familiar with X Y Z coordinates. I have done it a few times but more trial and error in positioning the light sources - just watching the red dot as it moves! May be good to do a Search, on Lights as the subject has been covered several times and you may pick up some tips.
There are easier ways by using other lights. In the example image I have used the same number of lights as there are fittings on the track but I have positioned them above the ceiling (so you cant see them - Ok if there is no room above!!) but lowered the light sources into the room and moved them closer to the walls where the light would be shining - as for example onto the frames (some of my paintings by the way). I have not attempted to hide the flush fluro lights used so you can easily see the idea. You can make them tiny and set things to invisible etc - it is the light source that is important. With the track light I have set the lens and frame ends so they are 'emmissive' (so appear to be lit up) and I have lowered the single light source for the track itself, so it does not make a single flare on the ceiling which would not be natural. (see 'Track Light Original image')
I have included the BLD file so you can see what was done with the lights although the options may not show up properly as as it will connect to your catalog not mine. If you install the BIM file (File/Catalogue menu) it should then give you the lights I have modified. You can also check my render settings.
If you can't follow it and need more detail just ask.
Allan
Allan,
As always, great tips on lighting and rendering!!!!
Thank You
Keith Wilson