Light is not the problem!

Seems many of you are not paying attention to the Render Report. Look at the ray firings of primary, secodary, and shadow rays. Here is where your questions will be answered. You will notice the more point lights you use the faster the shadow ray count increases. Usually shadow rays outnumber light rays by 400% for me. Understanding shadows is more important than understanding light when it comes to determining render times.

There are a few areas of confusion or misinformation in some of the previous posts I will address as follows:

Point Lights:

The default sun, radials, spotlights, all of these are considered point light sources. IBL, Domes, 3D Fills are cluster forms, made up of multiple point radials all managed as one. Point raidals have no physical size so they produce hard shadows by default. More on that in a moment.

There is a common misconception in the Bryce community that light is the enemy. On the contrary, it is the lack of appropriate lighting that ruins lots of Bryce renders daily. I will explain. Light is your friend and to get amazing results you need more than just the default sun and some ambience glow. There is so much more to lighting than that.

 

karl.garnham1,

Please have a look at my gallery:

http://www.renderosity.com/mod/gallery/browse.php?user_id=496780

I have pushed the limits on Bryce with indoor and outdoor lighting many times. Dimming light is unecessary and is likely detrimental to the final output. Bryce is already known and ridiculed for producing low contrast images. More light, not less, is the way to go. More contrast in the result is a good thing.

The brightness of a lightsource has no direct bearing on render time. You must have misunderstood something at some point in the videos. David and I have been friends for nearly 7 years and I dont remember him ever saying that. Light is not the issue. Shadows however, there is the rub.

Here are the things that do greatly affect render speeds:

1.Blend Transparency: This is by far the single slowest render function in Bryce aside from full volumetrics. Blend Transparency forces each light ray and each shadow ray fired to be fired multiple times adding to the render calculations. When a light ray strikes a solid object it stops and then a shadow ray is fired by the model onto othe rmodels. But when it hits a transparent object a second light ray must be fired along with a shadow ray. No wonder times increase as they do.

2. Normal Transparency: As mentioned above, transparency in general increases render time because secondary rays must be fired. But with optical transparency there is also the issue of internal reflection, which also increases render time.

3. Reflection: Reflection adds greatly to render time because it means more secondary light rays need to be fired as one surface reflects another. Limit reflection to where you need it.

4. Materials: You can light a scene using thousands of point light sources. If the materials are all neutral gray the scene will render in mere minutes. If however you have complex patterns in the materials, obviously the render will take more time. Lights alone are not the issue, it is the light combined with the textures that increase render time.

5.Shadow Intensity: By default the sunlight shadow intensity setting in the sky lab is 90%. The shadow setting in the skylab serves as the master shadow switch for all subsequent lights in the scene. Turn off sun shadows, it turns off all shadows for all lights. While 90% seems good at first, it adds to render time. Lower shadow intensity means that rays that would normally stop when they strike an object are instead fired a second and third and 20th time as they penetrate every surface in the scene on their way back to the camera. Believe it or not 100% shadow intensity speeds rendering.

6.Shadows 101: Lack of shadows is one of the things that makes Bryce renders look so cartoonish. In real life all light, even indirect skylight casts soft shadows that help reveal model contours and shape, making the image look 3d instead of flat and 2d. Lack of shadows will make the result look flat and 2d, which is usually not the goal. This is why IBL looks so good, because it gives both light and shadow from multiple directions just like in real life.

Scenes with a high degree of geometric complexity take longer to render due to increased shadows. Volumetric planes with detailed clouds take longer to render than less detailed clouds again due to the detail in the shadows.

Shadows are indeed what tend to cost the most render time, but they are essential. More lights means more shadows, so there is some degree of legitimacy to the notion that lights add to render time. IBL, Domes, and 3D Fills are comprised of multiple virtual point radials, so they add to render time. But if you think that the default sun and ambience alone are going to get you amazing results, you are wrong. We need light, so even if it takes a bit of time to render the results should be worth it. The more lights, the more you must avoid blend transparency. Dont use billboard trees if you want a fast render, use real 3d trees.

Ambience is evil and should be avoided at all costs whenever possible. Ambience bakes away the shadows that make a render look 3d. Replacing ambinece and skydome with actual radials floating around to represent light bouncing around the environemnt will give more plausible results.

 

Fozzibear:

Bryce 7 is not 64 bit, but it is LAA (Large Address aware). Bryce 7 can be pushed beyond 2gb to 3.6gb if you have enough system ram. Look at these two places for all the info you need.

http://forum.daz3d.com/viewtopic.php?t=155519&postdays=0&postorder=asc&start=0

http://www.techpowerup.com/forums/showthread.php?t=112556

Dont give up on Bryce. Bryce can do anything. It is right for all projects. Just look beneath the surface and you will see that Bryce is very capable.

 

Lastly, Bryce 6.3 is probably the slowest rendering release of Bryce yet. There was a bit of a snaffu if you will where Bryce 6.3 was released accidentally without a certain form of optimization being enabled. The results are that 6.1 is about 65% faster than 6.3. A step backward, I agree. Daz didnt seem too conccerned because they knew they had B7 coming out shortly afterward and it indeed has the opimization both enabled and updated. B7 is roughly twice as fast as 6.1, even moreso faster than 6.3.