View Full Version : BIG problems with HRD lighting ...

06-11-2003, 03:32 PM
I've read everything that I can find about HDR lighting in Lightwave on the net and in 'Inside Lightwave 7', but I can't seem to get anywhere near the tutorials I find on the net. Now, what is it that I'm doing wrong. I've messed around with this for a long time now, and just seem to get nowhere at all.

On the image below I've used nothing but color - no texture maps at all. I've imported an HDR image in the Image Editor (downloaded from Debevecs site if I remember correct), and added it in the Effects > Backdrop. Turned down the intensity on the one light in the scene to 0, and turned on Global Illumination. Set it to Raytrace both shadow and reflections in the Render dialog.

I've also played around with different settings, but it always comes out very grumsy, and just plain crappy. And where does all that noise come from?

Now does anyone have any 'beginners experience' to share? Cause I'm sure I've missed something. Just can't figure out what it is.

06-11-2003, 03:50 PM
Beginner here.....

i gave up on .HDR and started using .TIF

06-11-2003, 04:04 PM
reduce the scale of your objects, or raise the rays per evaluation

- Will.

06-11-2003, 04:31 PM
Your radiosity settings are fine (you might want to try interpolated for faster rendering).

First thing to do - turn off raytrace shadows, reflections, refraction. Your scene doesn't need these as there is nothing worth reflecting to that accuracy and you have no actual lights (HDR doesn't need ratrace shadows turned on).

Second thing - make sure your pen is to scale.

Thirdly - Go to the Camera properties and turn on dithered motion blur and enhanced low antialiasing.

Fourthly - In the Global Illumination panel turn ON Shading Noise Reduction.

Fifthly - there's the 3 ways it can work out the radiosity, Background, Interpolated, MonteCarlo. Background will render fastest but will be less accurate, MonteCarlo will take the longest but is most accurate.

Try these settings for each and see how it effects them (make sure you've done the above things):

Background - Rays= 4x12 (more is better but slower)

Interpolated - Rays= 4x12 (more is better but slower)
Bounces= 1 (more is better but slower)
Tolerence= 0.2 (smaller values are better, but slower)
Evaluation Spacing= 5mm (more is better but slower)

MonteCarlo - Rays= 3x9 (more is better but slower)

These are the settings I'd probably start from. I'd then tweak as necessary until it looks ok and the settings are as low quality as I'd like to get away with.

Hope this helps. May I also suggest the Beachprobe.hdr. I usually use this one as a good lighting test for models. Some other hdr's require some alterations to work well.

06-11-2003, 04:41 PM
Thanks a lot for the input. It helped me to see that I was going in the right direction, but simply wasn't aware of these (important) things.


06-12-2003, 01:48 AM
the main problem with hdris like the kitchen is that this hdris are high contrast pictures with only small light sources. this will produce noise. one major improvement is to use the hdr exposure plugin as an image processing effect. play with the values, you will see the results in the image preview. try to lower the contrast. you will lose less or more 'hdri' effect if you change the contrast. if you down to the level of a normal ldri (8bit per channel contrast ratio) you don't have to use a hdri anymore.
for such hdris like the kitchen one it is a better solution to create the main light sources with normal lights within lightwave and to use the hdri only for reflection. since this hdri doesn't produce really usefull ambient lighting you will get much better results (better quality of the rendering and extremly faster rendering) with lights instead of hdri lighting. turning on 'shading noise reduction' will kill nearly any detail in your scene, especially if you go to texture things, so this can't be a solution for everything.

06-12-2003, 02:23 AM
Try using the HDRI image that LW provides first - it could be the HDRI image you are using.

06-12-2003, 12:34 PM
Use a Full Precision Blur from Image Editor.
They will rid of your grainy noise.