Very long render times

Matz699

Hi, still relatibvely new to Daz but experiencing some very slow render times on what I believe are not complex scenes. Rendering a room view with limited lights towarss the end of the room, and no complex structures. Rendering for approx 1h now with no progress indicated. Walls are an object but tried collada format with similiar effects, too.Attaching screenshot of studio and current view on render. Had in run last night but timed out after 2h.

Any thoughts being welcomed.

 

 

Richard Haseltine

If you have just a couple of point lights (for Iray Linear Pointlights are just point lights) then a lot of surfaces are going to be relying on bounced light, the more that is true the longr the render takes to conerge. Adding some extra lights to help fill in the hard-to-reach areas and then using Tonemapping (or post work) to get back to the look you want may help - but given that a lot of the surfaces seem fairly flat you might also get good results using the Iray denoiser in Render Settings.

xXQuatroXx

Alright adding to what Richard said, iray don't like the dark all too much. Plus closed rooms always take longer to render because the Iray particles keep bouncing from walls to infinity instead of floating out of the room when they are of no use anymore.

So point lights or spotlights or add planes to light op the room and then deselect any walls that aren't visible in the viewport of that scene. you don't need to delete the walls but just deselect them. What I also sometimes do is move the sealing. if a part of the sealing isn't visible in the render then I move the sealing so that the part that isn't visible has an open sealing.

Now I hear you saying, "but if I open walls then the light of the outside will come into the room as well"

Not if you set the "dome" to Scene only, if you do that no HDRI light will show and the scene will be completely dark un till you add some lights.

If you still want some light to shine through the windows then add a plane in front of the windows outside of the room and have the plane emit some light....

PS. lights can be controlled from the lights tab or if the light is emitted from a surface then from the surfaces tab.

then furthermore is your hardware. The better the hardware the quicker the render, It's all about the Cuda's ;) and also Vram, if the scene is not being used by your GPU to render then it might be the scene is too big for your vram to handle.

Some times this happens on low-end cards with 2 or 3 GB of vram when there is to much in the scene or that the textures are to high in the scene. To overcome this issue you can look for https://www.daz3d.com/scene-optimizer in the daz store. This will defiantly improve your render times regardless of low-end or high-end GPU cards.

Render settings are also important enough to find about this on youtube. Give "WPguru" on youtube a shot. Lots of good stuff and a complete fun 101 TUT on all kinds of standard and more advanced techniques.

xXQuatroXx

in addition, my recommendation is to not use the denoiser at all on still images. I recommend only to use denoiser when doing animations.

PS. Little tip. If you do animations, render at 720P with denoiser if you are on a GTX 1080 (or 2) and then upscale the images to 1080P with photoshop with enhanced upscale technique using the batch tool to automate the upscaling. This will speed up your render time and make animations faster. Remember, the closer you are to an object or figure the longer it takes to render.

Matz699

thanks, will try some of the suggestions

 

dijitul

If you'd like to determine whether lights are the problem or not, simply disable all lights (including the camera's headlamp).  Run the render and see how fast it goes.  If there's absolutely no light, then it should be super fast and completely black.  However, if you still see light, it could be from the environment and/or emissive surfaces.  If it has these, then disable/remove those as well and test render again.  Once you have a completely black scene that renders fast, you should then test with one SPOTLIGHT only.  Adjust the spotlight's brightness as needed (for my default scene, I usually have it set to 150000.  You can parent it to the camera, zero it's transforms, then set the Z location to 10.  How fast does it render like this?  

If you're still expericing slow renders with just one spotlight, it's likely something else such as GPU rendering enabled (or fall back to GPU due to low VRAM), or caustics are turned on, or too many reflective surfaces.   Hope this helps.

Catherine3678ab

Could try making the render without the hair. Then do a render with just {almost*} the hair. Glue them together in an image editor. Hair can take a long time to render. At that distance might consider rendering in 3D with shadows {on the hair model's tab} turned off. {no way to turn off shadows with Iray}.

* leave the head showing, erase that clean in the image editor.