Top Blender Rendering Mistakes To Avoid For Beginners And Pros Alike

Forgetting to Set the Camera

One of the most common mistakes in Blender rendering is forgetting to set up the camera before rendering. The camera acts as the viewpoint in the 3D scene, so not configuring it properly can lead to unfocused, incorrectly framed, or simply blank renders. To avoid this, it’s crucial to position and adjust the camera during scene setup:


import bpy
cam = bpy.data.objects["Camera"]

cam.location = (5, -3, 10) 
cam.rotation_euler = (radians(45), 0, radians(15))

The above Python script demonstrates creating a camera object and setting its 3D location and angle rotation precisely. Taking the time to place the camera where desired pays off tremendously later. Camera options like focal length, depth of field, and motion blur also affect the final render and should be considered before launching a lengthy rendering job.

Low Sample Settings

Insufficient sample counts lead to renders afflicted by noise, graininess, dark splotches, and other artifacts. Samples control how many virtual light rays per pixel get traced in the scene. More samples equal cleaner, crisper results but also increased render times. There is a balance to strike – too few and image quality suffers; too many and time is wasted for only marginal gains.

Table of Contents

For quick draft renders, 50-100 samples is reasonable. For final high resolution images, samples between 500-2000+ may be needed depending on scene complexity. More advanced sampling techniques like adaptive sampling can help concentrate samples in noisy areas and optimize efficiency. Setting sample values too low is tempting for impatient users but severely hurts render quality in the end.

No Post-Processing

Neglecting post-processing fails to realize renders to their fullest potential. While Blender can produce nice raw renders, critical adjustments like color grading, exposure control, sharpening, denoising, and compression should not be ignored. These polish the image and correct many minor (but noticeable) imperfections.

For color correction, a versatile node-based workflow is recommended:


Compositor Node Tree:
Image Input Node > Color Balance Node > Hue Saturation Node > Composite Node

This node chain allows precise tweaking of colors, highlights, shadows, vibrance and more. The Image Input node feeds the raw render as the starting point, then color balance and HSV nodes apply adjustments, with the Composite node saving the finished image. Modifiers like smoothen, pixelate and distort can further transform the look as needed.

Ignoring Lighting and Materials

Properly lighting a scene and crafting realistic surface materials are crucial for aesthetically pleasing renders. Bad lighting causes ugly shadows, bright splotches, and flat objects. Poor materials look fake, plasticky, and fail to capture nuanced surface properties. Lighting issues stem from having too few light sources, light placement being too extreme, or brightnesses not balanced. Materials suffer when properties like roughness, metalness, subsurface scattering are not accurately configured.

For robust lighting, 3-point lighting with key, fill, and rim lights prevents uneven lighting and shadows. Light brightness and falloff can further soften shadows. On materials, measured settings for properties like 0.3 roughness, 0.9 metalness, and 2.0 subsurface radius greatly improve realism. Dialing these in just right takes experimentation but pays off for renders that “pop”.

Sloppy UV Unwrapping

UV mapping projects 3D meshes onto a 2D plane to correctly apply images and textures. Poor UV layouts with overlapping, stretched, or distorted islands yield textures that are warped, tiled, or bleeding across mesh seams. Clean, non-overlapping UV islands must be unwrapped to use textures effectively. Reference cube mapping on objects bounds can assist.

Best practice is marking seams along hard edges and borders, unwrapping mesh islands individually, then packing islands compactly in the 0-1 UV space. The example below demonstrates clean UV layout for optimal texture mapping:

Taking time to unwrap models properly gives far superior texture control compared to procedural or generated UVs. It maximizes texture resolution usage, allows baking of normals, shadows, and ambient occlusion, and keeps textures crisp regardless of mesh deformation animations.

Attempting Complex Scenes as a Beginner

Attempting overly complex scenes too early leads beginners to bite off more than they can chew. Intricate scenes with elements like buildings, landscapes, machinery, and creatures impose tough technical challenges. Common mistakes include uneven terrain, repetitive structures, misaligned architecture, texture tiling, and poor proportions.

It is wise to start simple and master fundamentals before expanding scope. Beginning modelers should focus on getting comfortable with modeling tools, materials, lighting, and rendering simple assets first. Detailed environments, intricate machines, realistic creatures, fluid simulations all introduce more advanced techniques. Rushing ahead risks frustration, while nailing basics clears the path for greater complexity later.

The above simple scene with clean modeling, materials, lighting, and rendering exemplifies mastering elements first before increasing intricacy.

Rushing the Rendering Process

With patience wearing thin after minutes (or hours!) of waiting, it’s common to prematurely stop renders before completion. Yet cutting renders short negates all preceding efforts, as frames must fully process for usable results. Insufficiently sampled renders exhibit artifacts, graininess, dark spots, and even missing components. It also wastes saved checkpoint images and computational investment.

For smooth rendering, first enable Save Buffers in Performance settings. Then in Render settings, use smaller Tile Sizes between 8×8 and 64×64 pixels for progressive refinement. Increase Samples gradually across test renders to gauge appropriate values. Most importantly, avoid pausing or stopping the render before all samples, bounces, and passes finish.

Rendering is taxing on hardware and not instantaneous, so patience during the long haul ultimately yields better outcomes. Restarting a stopped render may also introduce variance between passes.

Not Learning from Mistakes

Failure to analyze rendering mistakes prevents improvement and progress. Diagnosing why a render generated poorly provides key insights for troubleshooting problems and honing techniques.

Common issues to inspect include: noise/graininess, fireflies, blown out highlights, textures clipping, distortion, bad lighting, color banding, aliasing, depth of field fringing, motion blur direction, clipping through surfaces, and more. Tracing these render errors back to misconfigurations in lighting, materials, camera settings, sampling rates leads artists to make corrections and evolve.

With attentive iteration and analysis of imperfections, artists sharpen their eye for flaws, gain intuitions for parameter adjustments, better understand simulator underpinnings, and boost overall quality over time. Online communities like BlenderArtists, Reddit, StackExchange provide helpful collaborative troubleshooting when stuck.